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[Articles Home]  [Add Article]  

Plasma TV -- Mother of All RFI Producers

Paul D. Sergi (NO8D) on November 27, 2002
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Plasma TV --- Mother Of All RFI Producers

Have you noticed the big sales push by Best Buy (and others) of those plasma TV screens? You know, the ones whose prices have 4 digits in them. There are even payment plans where the price is spread over months or years to help you afford them. Many of these are going to be sold this holiday season.

Unfortunately, no one is mentioning the horrendous RFI that these things put out on HF.

I recently installed a CCTV system to keep an eye on my toys. The security company, ADT, suggested a Panasonic 42” Plasma TV/CCTV monitor since the light output was high enough that the pix could be viewed in broad daylight.

The morning after the installation of the plasma screen, I noticed a huge digital signal about 7.001 MHz and a few other places on the same band. Next, I checked 20 meters, then 15 meters. Same signal but a little weaker as I went up in frequency. Then, I looked at 80 meters - a gigantic noise at 3.505 MHz and other frequencies in the band. 160 meters was the same. What was this!

I did a little direction finding and found that it was coming from my house! Sure enough when I switched off the recently installed plasma display, the noise disappeared and I could hear the DX again.

The security company, ADT talked with Panasonic, who informed them that there was nothing that could be done. I owned it. I hooked up my HP Network Analyzer to see just how bad the problem was across the HF spectrum. It was unbelievably strong!

How strong was it?

Below, is a graph that shows the noise output of the plasma TV on the HP Network Analyzer. Those numbers on the right side of the graph represent db above the ambient noise level here inside the house. Yes, that would be 50 db at the top. That's about 8 S-units!

Notice how the noise is the worst on the low bands, but the rest of the bands are impacted as well. Your new Super Duper Signal Sucker receiver will definitely find this baby on any of the HF bands!

How did I get this graph?

First, I turned the Panasonic OFF.

Then, I placed a 2m rubber ducky antenna about 10 feet from the front of the Panasonic Plasma display. I took a reading across the HF spectrum and saved it to a diskette file, which I then imported to an Excel file. This allowed me to graph the ambient noise of the area.

Next, I turned the Panasonic ON and repeated the test, again importing it to the Excel spreadsheet. After subtracting the ambient noise curve from the second curve with the screen operating, I obtained the noise produced by the screen alone.

So What?

So, you are now saying, "So what - there's a big difference between 10 feet away and the distance between me and my closest neighbor. I might not hear that thing at all." You are SO wrong!

I have a 40m antenna that is located a quarter mile from my house and the signal levels from the Panasonic Plasma screen are still S-3 to S-5. Plus, this is off the back of the unit where the signals are attenuated by the metal casing. The signals off the front are stronger.

I have a 4 square for 40m located about 150 feet from the side of the screen and my `MP says it's S9+10db. So, unless the DX is stronger than that, you're likely to have a problem hearing them.

Let's look at some numbers

Just one Panasonic unit produces an S-3 raspy signal on lots of frequencies at 1/4 mile away from my antenna. How many houses are within a 1/4 mile radius from your house? 500? 1000? OK, now what percentage of those houses will have one of those super efficient raspy RFI generators by say, 2004? Let me guess at 2 percent. That means that you will have 10 to 20 of these things within the 1/4 mile radius of your station. Plus the prices are coming down which will result in a lot more of them. Got the picture?

The FCC will protect us, right?

This device, which is allowed to pollute the entire HF spectrum, is allegedly consistent with Part 15 rules; they say so right in the literature. It says that this device can't cause any licensed station any interference and it has to accept all the interference from licensed devices. Now all you have to do is get the rule enforced against all those people that surround you. Good Luck.

Some of the commercial airplane manufacturers are getting ready to use these things on commercial flights. The communication systems of the Friendly Skies are more concerned with VHF/UHF than the HF spectrum, so it's lucky for them that the spurious output of the screens is reduced as we go up in frequency. Even so, in order to comply with the regulations, some of the screen manufacturers have had to resort to a mesh over the front of the screen to form a sort of Faraday Shield that reduces the signals. Of course, this reduces the picture quality, too. So, don't expect your neighbors to start pulling the mesh over their screen to help you listen for the latest weak signal.

Apparently, the manufacturers don't think that those of us on the ground are worth the investment in shielding and the FCC backs them up with the limp Part 15 rules. Or maybe the Part 15 spawned the unthinking use of high voltage switching for a bright picture and RFI be damned attitude.

What can we do?

You could try one of the noise reduction boxes like the one made by MFJ or JPS but my experience has been that they require a lot of fiddling and retuning every time that you change frequency.

In any case, get ready for the RFI storm. It's forming right now at your local Best Buy and lots of greedy electronics manufacturers who don't mind polluting the spectrum while grabbing your money.

Is it true that if a device puts out a spurious signal on a certain frequency that it is susceptible to incoming signals of the same frequency? That's just a question. I'm not advocating anything.

Paul

NO8D

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Plasma TV -- Mother of All RFI Producers  
by N0NB on November 27, 2002 Mail this to a friend!
So, this makes perfect sense.

First, there is the discussion of pressure on the VHF+ bands (nothing new there) where everyone agrees that our HF allocations are relatively safe for the foreseeable future.

Now, we are greeted by consumer electronics (boy, there's a euphemism for shoddy design and throw-away upon failure planned obsolecense devices) that will wantonly polute the HF bands. I'm not surprised as I built a 1.33 GHz Athlon based computer last winter and it nearly wipes out the AM broadcast band along with 160m. There's still plenty of noise above 3.5 MHz, but I can live with it.

So, where does this leave us? For those of us living in a town, probably increasingly out of luck as time goes on. For those of us fortunate to live in the country with a half mile or more from our neighbors, we're probably in good shape as long as we don't buy one of these devices ourselves.

But, here's the rub. By sometime in 2007 (I think) the FCC has mandated that TV stations will be transmitting in digital format only, no analog TV transmissions will be allowed. I presume that means many more of these offending TV sets in the good old U.S. of A. Yessiree, progress and leadership brought to you by the federal government. What a waste.

On the other hand, will digital HF modes along with Software Defined Radio allow us to continue to use our HF allocations? Or, will the bands become so polluted so as to be useful only to hams in the remotest of areas. Of course we need to keep in mind the accomplishments the QRPp crowd has done with only millwatts. These devices, radiating in HF, are capable then of being heard all over the place particularly if the noise is conducted to the house wiring which may become a nice antenna. What a deal! On Sunday afternoons our DX friends will find comfort knowing that the good old U.S. of A. is watching the NFL and NASCAR.

Enjoy the DX now, because by Cycle 24 you might not be able to hear any of it.

Sigh...
 
RE: Plasma TV -- Mother of All RFI Producers  
by K5DVW on November 27, 2002 Mail this to a friend!
Unfortunately FCC part 15 is basically a barn door at HF, especially if you're located near the offending device.

Airlines SHOULD be worried about it if it's as bad as you predict. A lot of intercontinental flights use HF to keep in touch. Since I've seen these displays on planes, I can only guess they don't cause a problem to aircraft HF. They do a lot of testing to keep that from happening.
 
Plasma TV -- Mother of All RFI Producers  
by W4VR on November 27, 2002 Mail this to a friend!
I wonder if the ARRL and other users of HF (i.e. Federal Agnencies, etc.) are looking into this potential problem.
 
Plasma TV -- Mother of All RFI Producers  
by K4NR on November 27, 2002 Mail this to a friend!
A few years ago I found a strong signal on the bottom of 80 meters in my neighborhood. The bottom end of 80 meters was useless. I DFed it to a house just behind mine. I talked to the home-owner about the signal and I eventually figured out it was an FM signal from some type of wireless phone jack used for his daughter's PC modem (she used the line for voice now and then--I wonder if he would have wanted to hear what I had...). The ARRL was aware of the issue. Any way, I offered to replace the device with one that was not in the middle of 80 meters. I was told to "get lost".

I called CW with 1500 watts on the center of that frequency every night. I managed to have a number of nice CW QSOs despite the signal level from the neighbor. About a week later that signal was gone.

I'm sure my 1.5 KW had more impact on him than he had on me and I'll bet the device was useless anytime I was having a QSO.

73 de Tom, K4NR

 
RE: Plasma TV -- Mother of All RFI Producers  
by WB2WIK on November 27, 2002 Mail this to a friend!
This is scary.

I haven't run into this problem yet, personally, but it seems I've just been lucky.

Part 15 should help. As you likely know, the FCC doesn't actually get involved in the vast majority of Part 15 products; they make the rules and issue ID numbers, but independent labs do most of the testing, and in the case of major manufacturers, some of them have their own "in house" labs which are on the listing of accredited FCC labs and can thus self-certify without submitting anything at all to the FCC.

The placement of a Part 15 label on a product, and the standard Part 15 text printed in an owner's manual is no assurance that the appliance actually meets Part 15 requirements. In the verification process, normally only ONE sample is tested, and that can be a prototype.

Based on the data posted, I'd guess this particular unit does not meet Part 15 Class B requirements for radiated emissions, and I'd provide this report and the test data to the FCC immediately, prompting them to independently verify this product from a random sample.

BTW, in my (FCC listed) compliance laboratory here at work, we frequently test all sorts of labeled "Part 15" devices and find them out of compliance, and over the radiated and/or conducted emissions spec limits. The ones within the Class B limits rarely interfere with anything.

WB2WIK/6
 
Plasma TV -- Mother of All RFI Producers  
by KG6AMW on November 27, 2002 Mail this to a friend!
Plasma TV, meaning HD (high definition) flat panel tv that run anywhere from $2,000 and up, with $4,000 to $6,000 being the norm. The ones that are 3 or 4 inches wide. I know these TVs don't use the normal CRT set up, but maybe somebody can explain what it uses in its place. Like everything else, we need to identify the problem and start writing letters to the ARRL, FCC, and whoever else will listen. Yes, I know you don't think it will help, but lets start anyway.

Merrill
 
RE: Plasma TV -- Mother of All RFI Producers  
by N7TEE on November 27, 2002 Mail this to a friend!
Merrill,
What the plazma TV's use for the picture is a large group of small TV screens. They at the present time have a life expectance of about 10,000 hours of viewing before they have lost so many of the screens that they are unwatchable. If you have seen digital TV when the screen is afected by the weather with the black holes in the picture, that is a pixel and the plazmas each pixel is a TV screen. The projection TV's do not use the same amount of power to project the picture so hopefully the neighbors buy one of them.

Digital is different than High Def.. Digital is just the same band width as a regular TV station. The thing that is changed in the digital and regular TV station is to change from analog to digital (0's and 1's) for the picture. But the High Def. is about 6 times the band width because of all the information used in the picture. And is in digital mode also.
Hope that this helps.

73 Dave
 
Plasma TV -- Mother of All RFI Producers  
by W9ACF on November 27, 2002 Mail this to a friend!
If ARRL was worth a damn, they'd be fighting this tooth and nail......

It won't happen
 
RE: Plasma TV -- Mother of All RFI Producers  
by K4PDM on November 27, 2002 Mail this to a friend!
Whatever you may feel about the ARRL, they are our only hope.
I envisioned a future of interference-free HF because of the commercial push for VHF, UHF, and beyond.
In reality, the trend seems to be toward making the frequencies under 30 MHz into a garbage dump.
We have no one to fight this except the ARRL, however you may feel about them, and they'd better get a lot more of the ham fraternity's support than they are now getting!
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on November 27, 2002 Mail this to a friend!
This is but one of a number of potential threats to HF. Some of the posters are quite correct -- Part 15 is a sieve through which all but the very strongest of unwanted signals can be legally radiated.

These types of devices are unintentional emitters under the rules. Unintentional emitters deliberately generate RF energy, but do not intentionally radiate it. Another example of an unintentional emitter is a computer system.

Part 15 of the FCC's rules set limits on unlicensed emitters of RF energy. Unintentional emitters must meet radiated emissions limits above 30 MHz and conducted emissions limits below 30 MHz. That means that on HF, there is no specific limit on the amount of noise this type of device can radiate.

The manufacturer of the device is required to meet the absolute emissions limits. In the case of a device like this TV, the device must be Verified under the FCC Part 15 rules. This simply means that the manufacturer is required to have tested it for compliance and must have those test results available to the FCC, if an FCC agent asks for them.

This is the sole regulatory responsibility of the manufacturer. The Part 15 rules then stipulate that the operator of the unlicensed device must do so in a way that does not cause harmful interference. In most cases, the operator of the device is in our own household -- where we at least have some control -- or in a neighbor's house. Telling a neighbor that a brand-new TV he just bought at the local electronics emporium is being operated in violation of federal law is a conversation I would not want to have to have with my neighbors.

Even worse, the absolute-maximum emissions limits are extremely high, by amateur radio standards. The limits for intentional emitters on HF -- that can operate in the ham bands if they choose -- are 30 uV/m at 30 meters distance from the source. Translate: S9+15 dB to an 80 meter dipole located 100 feet away. The conducted emissions limits result in approximately the same levels, with the typical efficiency of power-line wiring.

By the time these battles get down to individual cases, the battle may be won, but the war is being lost. ARRL may have put in 500 staff hours dealing with the 3.53 MHz wireless modem jacks, ultimately succeeding in helping to persuade the manufacturer to make design changes, then working with AT&T cable to do a system-wide recall, taking care of 90% of the problem. But the potential in the rules is still there for the next noisy computer, the next new technology and the next widespread threat to HF.

This is best addressed at the regulatory level, and that is as hard a sell as I can imagine. Rather than doing nothing, as one poster implied, ARRL has been working with the FCC, power utility companies, and various equipment manufacturers to try to stem this tide on a case-by-case basis, and on the big picture. Over the past two weeks, I have attended the IEEE C63 "RFI" committee meeting in Baltimore and the TIA "VDSL" committee meeting in Altanta, giving these two standards bodies a detailed presentation on amateur radio and information that shows how the current rules are written in a way that harmful interference with amateur radio is likely. Similar actions are under consideration for the FCC. (There was an FCC staffer in attendance at my Baltimore presentation.)

Yes, these devices appear to be a potential problem, but not better or worse than my neighbor's noisy arc welder, my own tungsten outdoor light or a host of other intentional, unintentional and incidental emitters of RF energy. I guess ARRL *is* worth a damn, because it has devoted two full-time staffers to dealing with RFI problems, ranging from individual help to hams with problems to writing the ARRL information in the RFI Book to the numerous RFI web pages at http://www.arrl.org/tis/info/rfigen.html. Add to that its work with the FCC, manufacturers and standards organizations, to say nothing of the additional work done by the DC team internationally, and we have a program that has managed to get a lot done.

Could the League do more? Sure. If any of you can offer suggestions on how this can be accomplished with two RFI engineers at ARRL HQ (and a host of volunteers in ARRL's EMC Committee), pass them along.

ARRL's information on Part 15 is found at http://www.arrl.org/tis/info/part15.html.
 
Wonderful news for Condo Hams :(  
by G3SEA on November 27, 2002 Mail this to a friend!

Ah yes ! Imagine the future hash in condominiums !

Just one more reason to get on Echo-link !
 
Plasma TV -- Mother of All RFI Producers  
by W9JCM on November 27, 2002 Mail this to a friend!
Mm thats funny I have a plasma TV and have NO problems on HF here. Good luck. I wont get rid of my plasma its great!
 
Plasma TV -- Mother of All RFI Producers  
by W8UR on November 27, 2002 Mail this to a friend!
So you returned it, right? If not, then you're telling the manufacturer, with your dollars, that you willingly accept this interference.

And of course, should any neighbors purchase one, you'll shut them down with the FCCs help and a proper explanation that the fault lies with the manufacturer. Only by hurting the mfg in the pocketbook, through poor sales (unlikely) or through returns of these obviously poorly engineered devices will a timely difference be made.
 
Plasma TV -- Mother of All RFI Producers  
by WN3VAW on November 27, 2002 Mail this to a friend!
While this is a serious problem, and I'm certainly not belittling it, I'm curious as to why the author simply accepted the "you bought it, you own it" philosophy of the seller and manufacturer.

If the Plasma TV is radiating RF hash at these levels, it is clearly NOT operating within Part 15 rules, therefore it is clearly NOT operating correctly, and should be repaired or replaced under warranty -- it did come with a warranty, didn't it?

By all means, alert all of us to this problem, make sure your local club & it's RFI committee knows, and make sure the ARRL RFI staff knows (tho I'm sure by now someone has pointed them to this article if they haven't already found it). But I suspect that you will achieve a greater and more immediate impact and reaction by returning it and demanding replacement, repair or refund. They refuse? Then it's time for Small Claims court, and have a word with your local media (newspaper, TV, radio). Someone has a consumer reporter who just lives for stories of big corporations selling malfunctioning equipment for thousands of $$$ and then refusing to back the warranty...

In other words, if you have to, be the squeaky wheel and you will get the grease. Or as the book title goes, "Don't Get Mad... Get Even"

73, ron wn3vaw
 
Plasma TV -- Mother of All RFI Producers  
by N5SCP on November 27, 2002 Mail this to a friend!
Don't worry about it! Interest in this hobby is DYING and all you 'old fart hams' will be DEAD by the time there are 10,000 plasma screen TV's out there.
 
Plasma TV -- Mother of All RFI Producers  
by ETOWER766 on November 27, 2002 Mail this to a friend!
IF ANY OF YOU HAD SEEN THE INSIDE OF THIS (PANASONIC PLASMA TV) AS I HAVE, YOU WOULD UNDERSTAND WHY IT MIGHT PRODUCE OR CREATE RFI PROBLEMS. I WORK FOR A COMPANY WHO DOES AUTHORIZED FACTORY SERVICE FOR THIS BRAND AND OTHERS; WHEN YOU REMOVE THE BACK COVER---THERE IS NO SHIELDING BETWEEN THE SEVERAL PCBS AND THE REAR COVER----I HAVE SEEN MANY COMPUTER MONITORS WITH FAR BETTER SHIELDING INSIDE THAN THIS EQUIPMENT, AND I AM NOT SUPRISED AT THE RESPONSE FROM PANASONIC, I OFTEN SPEND 30 MIN ON THE PHONE TO GET THRU TO "TECHNICAL ASSISTANCE" ONLY TO HEAR"IF CHANGING THIS BOARD DOES NOT FIX IT, SEND IT BACK"

AT THIS POINT IN TIME NO ONE(EVEN PANASONIC) REPAIRS THESE TO COMPONENT LEVEL. THIS IS A NEW TECHNOLOGY THAT I BELEIVE IS FAR FROM PERFECTED. IF THIS UNIT CAUSES THIS TYPE OF RFI INTERFERENCE, WHAT HARMFUL THINGS IS IT DOING TO PEOPLE?
 
RE: Plasma TV -- Mother of All RFI Producers  
by KG0D on November 28, 2002 Mail this to a friend!
Hey there, N5SCP - you need a good @$$-kicking!

REAL hams are concerned about this issue. I'm sure that you as a big shot, so called "tech plus" (God that makes me laugh!!!!) won't experience much interference on your two-meter handheld radio (probably a Radio Shack model anyway), since all you do is hang out on your local repeater, trading "handle here is" and "10-4's", so butt out and let the real hams who you should be respecting speak on this issue.

By the way "Josh", why don't you turn off your playstation and crack open a book! Maybe Mommy will read it to you...
 
RE: Plasma TV -- Mother of All RFI Producers  
by N4EKV on November 28, 2002 Mail this to a friend!
Great info and chart, Paul. After being plagued by similar recurring birdies on HF from switching power supplies and wasting bux and time with mostly useless ferites, I too came to the realization that we hams were fighting a losing battle for quite, unpolluted airwaves. While the noise from switching power supplies probably isn't as severe as your plasma screen monster, switchers -- both in and outside of PCs -- number in the tens of millions and are growing rapidly..

Adam, N4EKV
 
Plasma TV -- Mother of All RFI Producers  
by KD7DCR on November 28, 2002 Mail this to a friend!
Paul (N08D),

One of the best written technical reports I have seen to date! Thank you for the extra effort.

I am about to make a major purchase, to "add" HF bands to my Ford Van for ARES/RACES situations...under the "what if" clause of Murphy's Law... This $1100 has taken 2 years to come up with and is only a reality now due to the big price discounts this winter. I was figuring that I would "use it" once in awhile.

After reading this report, I am now wondering if this may become my MAIN Operational mode = mobil? Living in a tract home, how else can I get 1/2 mile away from such messy devices? Not what I planed when I started into this hobby back in the 90's.

Up here in ID we make extensive use of the 40M and 75M phone bands for disaster work - 2M can and will fail you. Perhaps this angle, of Homeland Security and Disaster Response, can become a useful hook in any actions we are forced to take under part 15 (sic) rules. It might even be enough, along with the long range ARTC aviation usage, to get a class action basis declared.

Perhaps a data base should be established at ARRL into which we can dump our field reports by grid or long/lat for reference - via the web and email? IF widespread locations and datam can be documented early in this effort then attention from the FCC could be more forcably demanded.

Just my observations and feelings...we need to watch this one close!
 
RE: Plasma TV -- Mother of All RFI Producers  
by N2YTF on November 28, 2002 Mail this to a friend!
This is in response to the reply of another ham, N5SCP.

Interest in hamradio has never been higher. I was surprised to learn this but here are the facts:

There are more hams now in the US then there ever been in the history of the US, and the percentage growth of the number of hams in the US from 1980 to 2002 is absolutely incredible (I dont remember the number but I think it is about 80%).

The Editor of CQ magazine gave a speech at my club recently and revealed this and other facts about the US ham population and the ham population worldwide that really opened my eyes.

Older hams are important to the hobby and benefit ham radio (money and time to spend on the hobby) in many ways. Imagine how few manufactures would be developing and selling rigs if the hobby was made up of teenage schoolkids with only allowances to spend on gear parents may view as toys. I dont know how many teenage hams can match the spending of a retired ham or a ham nearing the end of his career (and perhaps near the top of the ladder). Hams living at home with parents may have difficulty in convincing non-ham parents to allow the erection of outdoor antennas as well. Also dont forget, in this time of political battles for every inch of spectrum voting age hams have great value to the hobby (compared with the younger ones).
I know there are some older hams out there that have lost their desire to explore new modes and learn about the hobby, but I know plenty of younger hams who do not explore and learn about the hobby for other reasons (budget constraints, too busy reading for class to read for a hobby as well).
Also I would say that a lot of older hams, by virtue of the fact that they have lived longer, are much better educated than some younger hams. A teenage ham hasnt lived long enough to complete a graduate degree and may not have completed a college degree. An older ham with a degree in EE or a similar field can do things in the hobby and contribute to the hobby in a way a younger ham cannot.

Younger hams are also important (may be more physically active and inventive in getting together cheap setups, may be longer term hams). Some schoolaged hams may have more time to devote to the hobby than some working age hams depending on work schedules and the seriousness with which the younger hams take their schoolwork and the older hams take their jobs. Personally I have heard many great stories about people operating from work from terrific locations that a school aged ham may have trouble competing with. The most recent story I heard was from a ham who worked at a factory and mounted a vertical on the top of something like a 300ft smokestack. I have also heard great hamming from work stories from the author of the Six Meters, The Magic Band book while at Ham Radio University (yearly event run by LIMARC).
I think that there are a lot of younger hams who, by virtue of being in school have active minds that are in the right "mode" for learning and are more likely to try out new types of operating and frequencies. Some (not all) older hams may have lost this.

All ages and types have a place in ham radio and have something to offer. Interest in the hobby is extremely strong historically and hams should realiaze that. Some hams in the 50's and the 60's thought ham radio was dying (check the old articles)....well to paraphrase the editor of CQ "we have been dying quite well for some time now"

73s
Thomas, N2YTF

 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on November 28, 2002 Mail this to a friend!
N4EKV writes:

< Great info and chart, Paul. After being plagued by similar recurring birdies on HF from switching power supplies and wasting bux and time with mostly useless ferites, I too came to the realization that we hams were fighting a losing battle for quite, unpolluted airwaves. While the noise from switching power supplies probably isn't as severe as your plasma screen monster, switchers -- both in and outside of PCs -- number in the tens of millions and are growing rapidly..>

Unlike most power supplies, which would be incidental emitters (power lines, motors, fluourescent bulbs, etc) and thus subject only to a requirement not to cause harmful interference, switch-mode supplies are oscillators and if they operate above 9 kHz, they need to meet the conducted emissions limits. They also have to have the FCC label about harmful interference, etc. If they (or their owner's manual) don't have this label, it is a sure sign that the manufacturer is not aware that the device needs to be tested for compliance. A few hams have sent me older switchers that we have tested above the limits.

The ARRL Lab ran around to a few of the home centers and obtained some of the current spate of switch-mode supplies and they all met the FCC limits. (Based on the description of the signal levels of the plasma TV in question, it, too, is more than likely compliant, although I would be willing to test it if it were sent to me in the ARRL Lab). If any of you have any info about noisy switch-mode supplies that are currently being sold, please send the model number and source to me at ARRL HQ. A good indication that a supply is above the conducted emissions limits would be S9 level noise from a neighbor's unit.

The League is staffed to help. Every single time ARRL files Comments with the FCC regarding Part 15 related issues, the answer is the same (to paraphrase): "The rules state that if harmful interference occurs, the operator must stop the interference or stop using the device. How much more protection does amateur radio want than absolute protection?" Well, if the Commission will back this, then the rule is reasonably adequate to permit relatively high levels of conducted and radiated emissions. If they FCC won't, though, this is critical information, and to the extent it can be documented, may serve as the basis of future ARRL filings.

To date, about 90%. As most hams have noted, the FCC has been sending letters to utility companies. What many hams don't know is that behind each of those letters is tens to hundreds of hours of ARRL staff time, trying to resolve this directly with the hams and utilities involved. This is part of ARRL's MOU with the FCC, which is the ONLY way that the FCC could possibly take on that number of cases. Riley recently gave me an interesting quote about the ARRL/FCC power-line work. He said, "I don't know what we would do without you -- probably nothing." In other cases, such as Darwin Networkings causing RFI on 2400 MHz, the FCC also was willing to initiate a contact letter. The Cinergy case that involved intermod between a power-line arc and WLW was another.

There are a few unfortunate cases where the local FCC field offices have reached decisions I don't think were correct. ARRL has been working with the FCC to try to get these resolved properly, although once a decision is made, it is mighty hard to get it reversed.

What the League does in cases like this is to first work with the ham. Local cases are best handled locally and if a solution can be found, in more cases than you might imagine, a neighbor is willing to cooperate -- if he or she knows what to do. (Why literally make a federal case out of a local problem?) In other cases, we can write a letter to a neighbor or smooth the way for a case to be handled by Riley, by first determining the level of interference and obtaining all the contact info. The Word file we send him is already formatted for his printer. :-)

The HQ staff is very interested in getting more reports of harmful interference involving unlicensed equipment. Best bet is to give me a call at 860-594-0318 and we can interact a bit to figure out what is best. (I believe that the involved ham is a much better judge of a local situation than I, so I almost always want to defer to local judgement about what is best.)

Last but not least, most switchers are conducting differential-mode noise onto the line. Ferrites probably won't work, but a brute-force AC-line filter (Radio Shack catalog #15-1111 or the filters sold by Industrial Communications Engineers may help.

73,
Ed Hare, W1RFI
ARRL Lab
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on November 28, 2002 Mail this to a friend!
<Perhaps a data base should be established at ARRL into which we can dump our field reports by grid or long/lat for reference - via the web and email? IF widespread locations and datam can be documented early in this effort then attention from the FCC could be more forcably demanded.

Just my observations and feelings...we need to watch this one close! >

It is one of many that need to be watched. I will probably take the Lab's R-3 to the local electrnonics emporium and see how much variation there is between models.

As to the database, Mike Gruber, W1MG, the ARRL Lab RFI engineer, is putting the finishing touches on the one started earlier in the year. It will be primarily used to help him juggle over 200 open RFI cases and to generate various reports and such (both for me to give my boss, but also of potential use with the FCC). We are also discussing the possibility to have an on-line reporting system and the best ways to share the results of the database reporting with hams.

Please do send report of RFI to rfi@arrl.org, so we can point you to the right information, count the RFI bean and offer some staff help, if needed.

73,
Ed Hare, W1RFI
 
RE: Plasma TV -- Mother of All RFI Producers  
by K4IA on November 28, 2002 Mail this to a friend!
I appreciate the fact the ARRL has been attending meetings and trying to raise the issue to RFI makers. But, let's get real here. Your are wasting your time, energy and resources if you try to convice them ham radio deserves protection. Instead demonstrate they need to reduce RFI to protect themselves.

Consumer electronics companies don't care one whit about a few ham radio geeks. They want to $ell million$ of expen$ive components and aren't going to change anything to make us happy. We lose both ways. If they interfere with us, so what. We are too few and far between to impact their bottom line. If we interfere with their widgets, we're the problem. Ask your neighbor whose fault it is when his mega-buck TV goes fuzzy. Just when we thought cable and satellite made TVI a thing of the past, it comes back to haunt us.

Part 15 needs revising. Here's how to get it done:
Electronics devices will interfere with each other. RF pollution from one plasma TV is bad for other plasma TVs. All consumer electronics devices are affected: computers, Tvs, wireless devices, networks, door bells, modems, alarms, etc. The manufacturers have to face that reality. This makes it a regulatory issue. The manufacturers need protection as much as we do.

Properly educated and motivated, the consumer electronics industry should welcome RFI standards. Otherwise, nothing will work. Your TV will set off your burglar alarm, but that is OK because the wireless dial up to the police won't connect and your garage door will be flapping up and down while your computer crashes and you can't blame it on that @#!*^ ham down the street because he gave up and sold his equipment.
 
Plasma TV -- Mother of All RFI Producers  
by KG6AMW on November 28, 2002 Mail this to a friend!
Give up the fight before hand? Come on, nothing beats a good dust up. Even if you lose.
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on November 28, 2002 Mail this to a friend!
<Consumer electronics companies don't care one whit about a few ham radio geeks. They want to $ell million$ of expen$ive components and aren't going to change anything to make us happy. We lose both ways. If they interfere with us, so what. We are too few and far between to impact their bottom line. If we interfere with their widgets, we're the problem. Ask your neighbor whose fault it is when his mega-buck TV goes fuzzy. Just when we thought cable and satellite made TVI a thing of the past, it comes back to haunt us.>

Although I agree about the view of the neighbor, this has not been my experience with industry. I have been pleasantly surprised at how well industry has responded. A good example is found in the 3.53 MHz wireless modem jacks. The manufacturer, when faced with a number of complaints of interference, redesigned their product to use a non-amateur frequency. The major customer, TCI Cable (now AT&T) responded by doing a system-wide recall of the devices. Why do you think this contact was a waste of time?

The Home Phone Networking Alliance designed a product that used 4.5-9.5 MHz to use residential and business telephone wiring to network computers. After joint testing with ARRL, their next version used 4 to 10 MHz, with 30 dB notches in the ham bands. Why do you think this contact was a waste of time?

The HomePlug industry consortium designed a similar product specfication to use HF to network computers using residential and business electrical wiring. I approached them with legitimate concerns and they, too, did some field testing with ARRL and ultimately put 30 dB notches in their product line.

The same concerns are being raised with the two major VDSL committees and the PLC industry. I disagree with you that doing so is a waste of time.

My opinion is based on my experiences. Perhaps you could share with us your experiences with industry that have led you to your conclusion that such contact will do no good. On what did you base your conclusion that ARRL is wasting its time in trying to work with industry?

73,
Ed Hare, W1RFI
ARRL Lab

 
RE: Plasma TV -- Mother of All RFI Producers  
by W5MIT on November 28, 2002 Mail this to a friend!
I doubt the FCC will crack down on Panasonic (or other plasma manufactures) because the FCC has a financial interest in the development of HDTV technology. As soon as HDTV sets are common place, the FCC will auction off additional spectrum currently allocated to analog television.

Also, if you use your Plasma display as a security monitor for you shack, I wouldn't think that you would need to have it on when you are in your shack, thus, problem solved!
 
RE: Plasma TV -- Mother of All RFI Producers  
by W5MIT on November 28, 2002 Mail this to a friend!
In responce to: N2YTF on November 28, 2002:

Actually, times are "a changing"... Teenagers have larger disposable incomes now than any other time in history. In fact, marketers have drastically altered their techniques to appeal to the teenage market, which is the fastest growing market segmet (this information from UC Davis economics department). Many teenagers work part time jobs.

As a high school student around the age of 16, I worked at RadioShack and a transportation engineering firm. I made enough to buy any of the best rigs, but chose to buy an IC-746 and then a FT-100D. Many non ham students spend thousands on their cars (many up to $10,000 before they graduate thanks to their spending more time working then on their school work and america's growing debt problem!).

Chances are, if the ham population was younger, you would have a greater emphasis on more technologically advanced rigs that might cost more money.
In my opinion, the main consumer of very expensive electronics equipment if probably the 30-40 year age group. Younger hams will probably also demand more technologically advanced equipment, including digital voice, high speed data, new fangled rig features in more compact sizes.
 
RE: Plasma TV -- Mother of All RFI Producers  
by K4IA on November 28, 2002 Mail this to a friend!
Ed

I do not mean to belittle your efforts. With all due respect to your hard work, you said it yourself: "By the time these battles get down to individual cases, the battle may be won, but the war is being lost. ARRL may have put in 500 staff hours dealing with the 3.53 MHz wireless modem jacks, ultimately succeeding in helping to persuade the manufacturer to make design changes, then working with AT&T cable to do a system-wide recall, taking care of 90% of the problem. But the potential in the rules is still there for the next noisy computer, the next new technology and the next widespread threat to HF."

It is time to stop fighting battles and go for the big picture. In the examples you give, I have to ask, why do regulations allow devices such as wireless modem jacks to broadcast signals in the ham bands or other allocated frequencies? In the example which started this article, why does the industry insist on shooting itself in the foot by designing devices that will interfere with each other?

My point was, you've got to convince them it is in their own self interest to regulate RFI. You will suffer death by a thousand paper cuts if you try to run around and fight these devices on a case-by-case basis.
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on November 28, 2002 Mail this to a friend!
<It is time to stop fighting battles and go for the big picture. In the examples you give, I have to ask, why do regulations allow devices such as wireless modem jacks to broadcast signals in the ham bands or other allocated frequencies? In the example which started this article, why does the industry insist on shooting itself in the foot by designing devices that will interfere with each other?

My point was, you've got to convince them it is in their own self interest to regulate RFI. You will suffer death by a thousand paper cuts if you try to run around and fight these devices on a case-by-case basis. >

I think we are saying the same thing. This is the very approach I take when I deal with HPNA, HomePlug, the VDSL guys and the IEEE C63 "RFI" committee. My presenation was not just a pitch about how wonderful ham radio is -- the contrary, it was a pitch about the need for them to offer more protection for amateur radio in systems that will be deployed in residential areas. My wireless modem jack example -- and the very real costs to the manufacturer and customers involved -- really DID get their attention.

The Part 15 rules permit radiated energy on any frequency. In fact, the permitted levels are about 100 dB less than the 50 milliwatt harmonic that is legal from a 500-watt HF transmitter... The premise of the Part 15 rules and our rather lax amateur spurious emissions requirements is that most of the time, such emissions do not cause widespread harmful interference. A 3.5 MHz radiator that was used in a mine would be just fine. The Commission feels that the "no harmful interference" clause is sufficient cause for manufacturers to consider what might be deployed near their product and choosing a frequency wisely.

Part of my job is to help them understand why choosing a popular ham band for their consumer product will be a big -- and costly -- mistake. So far, the successes have outnumbered the failures. :-)

73,
Ed Hare, W1RFI
 
Plasma TV -- Mother of All RFI Producers  
by W2XX on November 28, 2002 Mail this to a friend!
N5SCP Effective: 09 Jul 1994 ****Expires: 12 Feb 2001****


So long son, hope you cleaned up your room before leaving the building. Asshat.

 
HF will be dead in a few years from RFI  
by KF6IIU on November 28, 2002 Mail this to a friend!
My Mitsubishi 27" conventional TV puts out S5 to S9 spikes every few khz all the way into VHF, has done so for years. I canot operate with it on. So TVs have always been a problem.

RFI will be the downfall of HF within a few years. I have S5 to S9 QRM on 20 to 10 meters at my home QTH 24 hours a day. On 10m, which is the only band I have a mobile rig for, the noise is S3 to S7 EVERYWHERE within a 1/2 mile radius of my house. The noise goes away a couple S units at night, but is back every day, and is worse on hot days. The power company (PG&E) has been out to visit but clearly doesn't have the resources or know-how to track it down, even assuming it is a power company problem.

Forget antenna restrictions. Forget about band allocation grabs. The proliferation of cheap crap electronics from overseas will doom HF soon. Part 15 is a joke.
 
Plasma TV -- Mother of All RFI Producers  
by M0AFJ on November 29, 2002 Mail this to a friend!
Maybe its about time for the US to adopt the CE regulations for Emissions and Immunity testing of all elactronic products. Its not perfect but I'm sure that a product like the Panasonic TV screen would not be allowed to be sold in the EU.
We do have problems in Europe but the EU regs are policed. We recently had an instance of a hair dryer which was being sold under a well known brand name which was found to be exceeding the conducted emissions regs, the fine was a few thousand dollars BUT the product had to be withdrawn from sale which cost the company a lot more.
We should be more worried about PLT technology, where HF data is transmitted down power lines to the house, God knows what will happen to HF when this is available.
Maybe the ARRL should campaign for the CE regs to be adopted in the US, It may even open up a few markets for you all, (we are one of the biggest trading blocks you know!).
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on November 29, 2002 Mail this to a friend!
<Maybe its about time for the US to adopt the CE regulations for Emissions and Immunity testing of all elactronic products. Its not perfect but I'm sure that a product like the Panasonic TV screen would not be allowed to be sold in the EU. >

Maybe, but if memory serves, the US limits for conducted emissions are 250 microvolts across a 50-ohm LISN (line impedance stabilization network). This is the RMS voltage at the peak of the waveform,in a 9 kHz bandwidth for HF. This "legal" Part 15 emission can result in a received signal level of up to S9 on 3.5 MHz to a halfwave dipole located 30 meters away from the source. More typically, the noise is broadband, and at typical "antenna" gain for the power line of minus 20 dBi, an S5 to S7 noise level would be common. I don't believe that the CE regulations are significantly lower than this.

<We do have problems in Europe but the EU regs are policed. We recently had an instance of a hair dryer which was being sold under a well known brand name which was found to be exceeding the conducted emissions regs, the fine was a few thousand dollars BUT the product had to be withdrawn from sale which cost the company a lot more.>

In the US, a hair dryer would be an incidental emitter, with no limits on radiated or conducted emissions.

<We should be more worried about PLT technology, where HF data is transmitted down power lines to the house, God knows what will happen to HF when this is available.>

I know exactly what will happen -- the noise levels will be horrendous unless the industry takes steps to protect amateur radio. Significant progress has been made in that area, with the HomePlug specification including 30 dB notches below the level that the FCC permits carrier-current devices to operate. But whether the access PLC industry (internet over powerlines) will follow suite remains to be seen.

<Maybe the ARRL should campaign for the CE regs to be adopted in the US, It may even open up a few markets for you all, (we are one of the biggest trading blocks you know!).>

That may or may not be a good idea. In some cases, having stringent regulations cast in stone can be a double-edged sword. If the only regulatory responsibility is to meet the limits, then manufacturers will rest on their laurels. I have already seen a few cases where FCC field offices have looked at the Part 15 label on equipment and told neighbors of hams that it meets the FCC regulations, so no additional filtering is necessary. Right now, the US rules are high, but there is an additional provision about harmful interference. I am still testing the FCC waters on that one.

I once thought that immunity requirements were important. I have changed my mind. The CE regs have, if memory serves, an immunity level ranging around 3 volts/meter. This translates to 100 watts to a dipole located 30 meters from a neighbor's house.

The level that would be necessary to really protect amateur radio operation would be more like 30 volts/meter. IMHO, this doesn't have a chance of flying, and if the FCC were to adopt an immunity regulation, it would be somewhere near 3 volts/meter.

In Germany, the regulators took it one step farther. They recognized the imbalance between a 3 volt/meter immunity law and the fact that amateurs can create fields 20 or more dB above this in their neighbor's homes. They then mandated that amateurs not exceed 3 volts/meter to protected equipment, and the amateurs are required to determine that in advance.

73,
Ed Hare, W1RFI


 
The Curse of 10,000 Plasma Screens  
by WB9GKZ on November 29, 2002 Mail this to a friend!
Once the count in my neighborhood reaches 10,000 I'm
gonna disconnect all my antennas. I'll stack all my Kenwoods, Yaesu's and Icoms on one side of the room...on the floor. I will then light a candle in the hamshack and start chanting in Morse Code, staring at the flame. I will not shave or trim my fingernails.
All of my meals will be slid under the shack door. They shall call me the Radio Recluse....I will not show myself until Part 19 is fully enforced.

Pat WB9GKZ
 
RE: The Curse of 10,000 Plasma Screens  
by N6AYJ on November 29, 2002 Mail this to a friend!
Wow, this is really a problem! If we get too many of these plasma TV's in general use, you guys won't be able to get on HF and talk about your prostate problems anymore! I agree with K5SCF. I recently searched the FCC ham database by zip code and found 4 people in my town whom I knew, but I didn't know were hams. When I spoke to them about ham radio, they ALL said they never get on the air and would probably let their licenses lapse: the local repeaters were too unfriendly, and hams on HF were too judgmental and always talking about their medical maladies. It's a dying hobby. I've been a ham for 42 years, and I say. "good riddance". Bill Crowell, N6AYJ
 
RE: Plasma TV -- Mother of All RFI Producers  
by OBSERVER on November 29, 2002 Mail this to a friend!
Great article Paul, thanks for sharing your findings with us. I am surprised that a good radio with IF-ANF DSP doesn’t knock out those plasma birdies…

Face it guys, the hobby is slowly dying. It has been a gradual decline, but never the less it is declining. If you think I am full of it, look at the statistics, and age distribution of the amateur population. The average age is gradually creeping upward with very few younger folk's entering the hobby. So, we might as well have fun while the hobby is still here.

Last I checked the typical overweight, out of shape, cigarette smoking, RF absorbing Ham does not have a longer life span than most folk's. First, I suggest that Hams stop smoking, over eating and start up a good healthy diet and exercise program. Put a treadmill in the shack and mount that radio in front of it. Take advantage of some of those remote base capabilities and ride your bike while working a contest. With all of this in place, we might be able to extend the hobby out a few years as the average Ham’s life span increases. Second, I suggest that we petition the ARRL and FCC to lift the maximum allowable power limit from 1500 watts to unlimited. That way we can eliminate or overpower those “plasma jammers” and take back our spectrum!
 
RE: Plasma TV -- Mother of All RFI Producers  
by W9ACF on November 29, 2002 Mail this to a friend!
500 hours spent on RFI.... Be still my beating heart! Quit talking about who joined the staff and who died and who got elected to a position in ARRL. Focus people!
 
Plasma TV -- Mother of All RFI Producers  
by AC0X on November 29, 2002 Mail this to a friend!
Doesn't anyone remember the old TV sets that would cause QRM every 15.75 kHz?

 
RE: Plasma TV -- DTV backstory.  
by KB3DVS on November 30, 2002 Mail this to a friend!
As a television producer, I must comment on various facts presented here:

by N0NB on November 27, 2002
> By sometime in 2007 (I think) the FCC has mandated that TV stations will be transmitting in digital format only...
> will digital HF modes along with Software Defined Radio allow us to continue to use our HF allocations?
> Or, will the bands become so polluted so as to be useful only to hams in the remotest of areas.

Digital TV began broadcasting several years ago in the top markets.
By the end of 2002, all markets will have at least one DTV signal on the air.
Most are already complete with a DTV signal on the air for every broadcast signal.
If you're not already hammered by the "noise" of a digital broadcast, then they're doing it right.
Moreover, the vast majority of stations on the air with DTV have found that they can get equal or better coverage with DTV at significantly less power. So instead of being 50,000 watts, they have started up at 12,000 w and were surprised to have achieved 95% coverage of their anaogue signal.

by KB7WJL on November 27, 2002
> What the plazma TV's use for the picture is a large group of small TV screens.

I can't get into it because I don't fully understand the engineering involved, but the name is accurate. There are plasma gasses that are excited with high voltages in each of the little "pixel" chambers. It's not LCD or LED. It's certainly not little TV screens.

> The projection TV's do not use the same amount of power to project the picture

Projection TV's, more accurately, enclosed rear projection TV's are completely different than Plasma screens. Projection TV's use CRT, DLP or LCD video projectors and bounce the video around in the box to get the distance needed to focus the video on the translucent plastic screen. They all draw different power based on the requirements of the actual projector and other tuning hardware inside. Perhaps less than a CRT of similar size, but still sizable if the screen is to be bright, and they vary dramatically depending on design.

> Digital is different than High Def.. Digital is just the same band width as a regular TV station.

Very true. DTV is already on the air. Channel 29 may be FOX, Channel 30 may be FOX-DT in your city. In fact, DTV may not be TV at all. A station can broadcast internet data as part of its stream. They can offer tailored Muzak for busses and other numerous mobile recipients. DTV is very open.

> But the High Def. is about 6 times the band width because of all the information used in the picture.

Actually, no. It may be 6x the data- uncompressed, compared to an uncompressed SDTV signal. However, the broadcast bandwith was deliberatly limited to no more than is already given for analogue broadcasts. So the frequency edges of the "channels" remain the same, no matter analogue or DTV. The total data stream is about 19 megabits per second (Mbps). No matter what is inside it.
Furthermore, every DTV transmission is MPEG-2 encoded- similar to a DVD. The bitrate is so low that stations can easily multicast 4-6 standard definition signals in the space allocated. DVD's are usually mastered at 4 to 6 Mbps. I've read of stations offering a 720p HDTV broadcast AND a SDTV stream at the same time. Nevertheless, no matter what the station broadcasts, it has to fit in the same channel space as has existed for decades.

by ETOWER766 on November 27, 2002
> IF THIS UNIT CAUSES THIS TYPE OF RFI INTERFERENCE, WHAT HARMFUL THINGS IS IT DOING TO PEOPLE?

Good Question. Hopefully OLED's will develop quicker than they have been and overtake the big and heavy plasma screens before they get a firm foothold in the marketplace.

by W5MIT on November 28, 2002
> As soon as HDTV sets are common place, the FCC will auction off additional spectrum
> currently allocated to analog television.

I've read this too, however, after seeing how the channel allocations have been as broken up as the anogue ones, there is no blanket spectrum, save the channels in the 60's, that will be garnered. For various reasons different in each location, channels are as spread out through the VHF and UHF frequencies. This means that the existing channels aren't getting all packed into channels 40-60 on UHF, they are sprinkled from channel 2 (VHF) all the way up- just as they are now. IMHO, a waste of spectrum.

Anthony
 
Plasma TV -- Mother of All RFI Producers  
by VK2HL on November 30, 2002 Mail this to a friend!
Well well... I wonder how many of the fruitcakes that protest against cellphone antennas park their kiddies in front of one of them!

Cheers
 
RE: Plasma TV -- DTV backstory.  
by KB0NLY on November 30, 2002 Mail this to a friend!
First off i want to commetn on the posts calling it a dying hobby. The hobby isn't dying nearly as fast as the hams in it! I can search on my Zip code for licensees and it shows more than are ever active, why you may ask? Well first of all over 50 percent of them are in the retirement community, a rather nice group of apartments on one end of town with antenna restrictions, another 20 percent of them are facing down death on a daily basis in the hospitals elderly care unit, and the remaining 30 percent around here are usually chatting once or twice a day on the local repeater between working and spending time with the family. Unfortunately that 30 percent is slowly declining into the other two groups, i have tried to get friends and family interested, but how do you interest someone who says, and i quote:

Oh yeah the whole morse code and shortwave radio thing, you guys still do that stuff, i just jump on the internet and talk to family and friends in three different continents without that static and interference.

Unquote.

Let's face it people, it is happening in some areas more severly than others. I love Amateur Radio, always have since the first time i heard a voice come over the radio saying my name, i was 15 at the time and amazed in how someones voice could travel through the air from antenna to antenna.

I am working on my upgrade to General harder than ever this year, i bought a new all in one HF,VHF,UHF radio and want to use HF to be able to talk to someone that isn't a local, there is four local repeaters that i scan through most of the day when i am in the shack, and all four of them stay quiet for periods of days at a time, and would stay quiet longer if not for weekly nets and local club meetings. An those club meetings are getting short, after all there is getting to be a lot of empty chairs and not many new faces.

I don't want to get flamed on here for saying this, i'm just trying to calmly and politely relate what i see on a daily basis where i live. Another problem that i will only briefly touch on is the CW requirement for HF use, ok so some people like or even love using CW, that's great i'm not trying to say you can't use it, but boy do we need to eliminate it. I have seen way to many heads shake no when i tell them that it requires a CW test to get on HF, and then i realize that person just gave up on our great hobby and went back to his/her computer.

Ask anyone that works for the post office how Email has killed mailing personal letters, and how online bill paying has hurt the sales of stamps and money orders and priority mail envelopes, the list goes on, why do you think stamp prices keep going up! I work from my home in the computer biz, i build and repair and upgrade computers for a living folks, it has been a real change in the last few years as far as the age of computer users, i got clients that are having me teach them how to do things with there computer in there 70's!! Computers and the internet are doing the same thing to Amateur Radio that it did to the USPS.

I don't want to hurt anyone's feelings, and i have nothing but the utmost respect for the "old farts" of the hobby. You OM's are the reason i love the hobby, but that doesn't mean that i have to jump off the bridge because everyone else is doing it, there are new and exciting things to do in the hobby and we all need to step back and look at the new ways to enjoy it. And sometimes a part of something we love, as CW requirements is a part of Amateur Radio, has to be let go so the thing we love lives on.

Just my $1.95 worth on the posts relating to the "dying hobby" HI HI.

73,

Scott, KBØNLY

 
Plasma TV -- Mother of All RFI Producers  
by KG6AMW on November 30, 2002 Mail this to a friend!
Possible plasma TV interference is just one more problem to solve. Your choice is to make the best of everything or sit around and bitch about people and life. I've been in this hobby 2.5 years and made several good friends in that period of time. I don't what they look like and maybe they are old and fat, but I do know a little something about their mind. Ham radio is dying, so what. I'll make the best of it and if lasts 10 months, 10 years or 50 years, I'll enjoy it all. Get out there, use the bands, support the ARRL and add something to ham radio. Get busy living or get busy dying.
 
RE: Plasma TV -- Mother of All RFI Producers  
by KA4KOE on November 30, 2002 Mail this to a friend!
Its amazing how these threads go from RFI producers (the original topic) to the death of amateur radio and sedentary hams dying off in droves....my 10 year old little girl is burning to take her Tech exam.

Anyway, IMHO, from what I have seen and read at industry trade shows, plasma screen technology will most likely be overtaken by large active matrix displays or by ultra thin organic types. In the latter, it is conceivable that the display could be rolled into a poster tube. You get the thing home, and then stick it to the wall as you unroll it. Imagine that! Small organic displays now on the market are about the thickness of a nickel.

Plasma displays are still limited by high cost, burn in (they're just as susceptible as standard CRTs), pixel drop outs, and, most importantly, lifetime of the phosphors. We're talking 20K hours folks....which is comparable to a standard F32T8 fluorescent tube.

What you buy now at under 5K in the various "Best Buys" of the industry are usually bottom of the barrel and low resolution types.

Anyway, the gist of all of this is that don't get too upset by the RFI problem of plasmas just now.....again, IMHO, they are already obsolete and about to be overtaken by other technologies.

Philip Neidlinger, PE, CTS
KA4KOE
 
Plasma TV -- Mother of All RFI Producers  
by AC0X on November 30, 2002 Mail this to a friend!
We used to have to tolerate TV sets that had such noisy TV sweep frequencies that one set in a house would cause strong harmonics every 15.75 kHz. Yet we survived that. We used to have to live in a neighborhood where *no one* had cable and most *every* TV set was *SO* susesptible to overload that we even a QRP signal would wipe out reception. But we survived that. I suspect (with ARRL's assistance), we'll survive this, too.
 
THE SKY IS FALLING!!!! (well.....)  
by AC0X on November 30, 2002 Mail this to a friend!
On a side topic....

I wish everyone who keeps saying that "ham radio is dying" would just SHUT UP. If you think that's true and believe that's a good thing, then why do you post here? This is a HAM RADIO web page. Go back to looking at your favorite porno sites. If you think "the death of ham radio" is a BAD thing, then stop yer whinin' and DO something about it. Join a club, elmer someone. And please stop yapping how "all the hams near me live in retirement homes". If what you want isn't in your backyard, go looking for it. This is the year 2002. There are TONS of "ham radio clubs" on the web you can join, each with people who have questions that you might be able to help with.

Besides, despite the claims of the chicken littles out there, ham radio is NOT dying. Come to the VE sessions I go to. I'm STILL seeing (2 1/2 years after restructuring) many more exam candidates then I saw in the years previous. There are still 685,000 licensed amateurs. Even if the worst month for license losses in recent years (Sept 1997) where the number of hams dropped by 1300 gets repeated EVERY month from now on, that's over FOURTY YEARS before that number gets depleated. And that month was NOT usual. Check the numbers. On average, over the last handful of years, the number of licensed hams has *INCREASED*. The "Great Expire-Off" the naysayers predicted would happen in the last couple years as the no-code tech licenses expired *HASN'T* happened.

Ham radio DOES need our support if it's going to survive, grow, and even thrive. But we have to remember what we're doing is "feeding it to keep it healty", not simply performing CPR on a near dead corpse.
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on November 30, 2002 Mail this to a friend!
<We used to have to tolerate TV sets that had such noisy TV sweep frequencies that one set in a house would cause strong harmonics every 15.75 kHz. Yet we survived that. We used to have to live in a neighborhood where *no one* had cable and most *every* TV set was *SO* susesptible to overload that we even a QRP signal would wipe out reception. But we survived that. I suspect (with ARRL's assistance), we'll survive this, too. >

While I suspect that the "plasma TV" problem might be more like a noisy switch-mode power supply in the particular model, this whole Part-15 issue is a biggie. A few years ago, I saw an ad for a computer-controlled outlet strip. In one of my articles, I mused half-jokingly that now I could interfere with my neighbor's extension cord. I didn't give much thought to the fact that now my neighbor's extension cord can interfere with me.

The proliferation of noisy devices -- being made under rules that have been with us for decades, but are just now starting to see more widespread deployment of devices - could, in some areas, wreak the death of a thousand small cuts on HF and even VHF operation. As I tune HF, especially my favorite band, 40 meters, I hear "signals" that I do not recognize, and not all of them are amateur. As I drive around mobile on 80 meters, I hear all sorts of stuff and with companies looking to implement access PLC technology, I am actually getting a bit nervous. So far, we are not even a full step ahead of the Devil, and there have been a few close calls.

Back when TVs were becoming popular, susceptible TVs and amateur harmonics caused quite a bit of TVI. There were those who predicted the end of amateur radio. They may have been right, but for Lew McCoy and other hams who recognized the problem and realized that solutions were better than dire predictions.

I have faith in amateur radio today and I believe solutions can be found for the problems that face us. In the Part 15 case, it will not be a one-man show, though I hope to help keep ARRL in the fray from start to finish. But ARRL's strength is not found in any one individual, but in the fact that members are willing to fund a paid staff to do the work and members are willing to volunteer some of their time and expertise where needed. "My" RFI work at ARRL HQ has not been my work. The RFI Book was written by a team of experts, only one who works at ARRL HQ. All I have learned about RFI, I have learned by talking to knowledgeable hams in the field, who have given their input and guidance to me and to ARRL.

IMHO, this is what makes amateur radio strong, and I am honored to be a part of it.

73,
Ed Hare, W1RFI


 
RE: Plasma TV -- Mother of All RFI Producers  
by KD5SZW on December 1, 2002 Mail this to a friend!
Excellent article, thanks! Just a quick "attaboy" to Thomas, N2YTF for the "extra " class shown when he responded to another ham's comments. I't folks like you who are the reason ham radio is what it is, and always will be.

73's
Dennis Wood
 
Plasma TV -- Mother of All RFI Producers  
by K4OG on December 1, 2002 Mail this to a friend!
I purchased a Panasonic 42" Plasma Display about a month ago. It is an impressive, vibrant display and is a great addition to the home theater. But, when it comes to RFI, I'm not sure if it is the "Mother of All RFI Producers" or not, but it sure is a Mother something. Loads of crud on the lower bands and no amount of my tinkering has put a dent in it. But when I shut the display down, this racket goes away, but then all I have to contend with is power line hash and noisy dimmer controls in the area. Which BTW, is almost at the same level as the "Mother of All RFI Producers"
 
Plasma TV -- Mother of All RFI Producers  
by K8DIT on December 1, 2002 Mail this to a friend!
Whenever I see the phrase, "Mother of" I smell hoax.
Could it be another tempest in a teapot? Noone has
declared, "Stop the Madness," but it may be appropriate. Hams, like everything else that's wholesome and goodly in America, is not going anywhere
anytime soon. If Plasma TVs begin to produce victims, then lawyers will turn large profits into losses by class action suits, the EPA will ban them and the Media will make money exposing them. The producers of these products know this, so I think that this topic has excellantly stirred the pot and produced the necessary awareness that will never amount to much because we are now aware and watching Big Brothers every move, conspiracy theories aside, and Plasma TVs will quietly become a non topic from here on, forevermore.
 
RE: THE SKY IS FALLING!!!! (well.....)  
by KC9OD on December 1, 2002 Mail this to a friend!
My Rural Electric Member Co-op board of directors has voted to replace the existing metering devices with new ones capable of remote turn-on/off, remote metering, and "home security" options. This means the power line itself will become a miles long radiator of digital garbage.
Besides the simple feedthru meter which could be pulled tin case of a real emergency will be replaced with something that if I/whomever can't contact an operator means the power CAN'T be shut off in case of fire, etc.

Not everything needs to be digital; I have a DIGIT for those who want to pollute the spectrum.
Being the last house on a quiet road is about to end as several developers are poised to build a dozen houses next door. At least my property lines are 700 feet from the house ,but it sounds like 7000 is what's needed ! Well, the hams out West should still be able to work some DX.

Maybe we will NEED those California Kilowatts just to work each other.
 
RE: THE SKY IS FALLING!!!! (well.....)  
by W1RFI on December 1, 2002 Mail this to a friend!
<My Rural Electric Member Co-op board of directors has voted to replace the existing metering devices with new ones capable of remote turn-on/off, remote metering, and "home security" options. This means the power line itself will become a miles long radiator of digital garbage.
Besides the simple feedthru meter which could be pulled tin case of a real emergency will be replaced with something that if I/whomever can't contact an operator means the power CAN'T be shut off in case of fire, etc.>

This type of power-line communications is authorized under Part 15. They have no specific conducted or radiate emissions limits, but are limited in frequency, if memory serves, to below 2 MHz. Virtually every utility in the country uses such PLCs to remotely turn on and off equipment. Most operate below 300 kHz and send only very short bursts of data at slow speed. This type of PLC does not pose a significant threat to amateur radio.

Access PLC, however -- internet access over power lines -- is another story. It does pose a very real threat and if my calcuations are correct, may be capable of raising local noise floors by as much as 50 to 70 dB.

73,
Ed Hare, W1RFI
 
OUCH!!!!  
by N2MR on December 2, 2002 Mail this to a friend!
In Germany, the regulators took it one step farther. They recognized the imbalance between a 3 volt/meter immunity law and the fact that amateurs can create fields 20 or more dB above this in their neighbor's homes. They then mandated that amateurs not exceed 3 volts/meter to protected equipment, and the amateurs are required to determine that in advance.
 
RE: Plasma TV -- Mother of All RFI Producers  
by KE1MB on December 2, 2002 Mail this to a friend!
good for you K4NR, I had a neighbor who checked up on me with the FCC and found there was nothing he could do, I suggested in a nice way that he could either take the filters I was offering and install them, or scream and yell at me and then therefore never be able to watch TV, talk on his phone, or use the internet ever again. He choose to keep his mouth shut and take the filters.
 
RE: THE SKY IS FALLING!!!! (well.....)  
by WB2WIK on December 2, 2002 Mail this to a friend!
Well, my next door neighbor just had a new plasma screen TV delivered on Saturday, and I haven't heard a peep from it yet. <Whew!>

I know he had it turned on Sunday around noontime, for a football game, because I visited him to see how he liked the new "rig." He loves it, and it sure is very, very bright and clear. I ran home quickly to tune across the HF spectrum, but didn't hear anything unusual. I turned my HF beam right at him, but that's not a close one because the beam is about fifty feet higher than his house, and obviously not really aiming "at" his TV set. I'll try this again, next time the tower's cranked down.

So far, so good, though!

WB2WIK/6
 
RE: Plasma TV -- Mother of All RFI Producers  
by KA5S on December 2, 2002 Mail this to a friend!
It's worse than 250 uV; that's with a Quasi-Peak detector. This a detector with attack and decay time calculated to deemphasize noise that has proven in studies less irritating to radio listeners. Low-duty-cycle emissions may have a peak value MUCH higher than the quasi-peak value measured.

I have LISN's and I really should hook up some of my consumer stuff and see what they put out.

Cortland
 
Plasma TV -- Mother of All RFI Producers  
by WR8Y on December 2, 2002 Mail this to a friend!
Another Chicken Little weather report: "The sky is falling, the sky is falling...." Ham radio was tougher in 1974, the TV tore up all HF bands and I tore IT up!!!! Now, with cable and better TVs all that is behind me!

Ham radio is easier these days.

As for 'cliff dwellers', well, they've never had it easy....

Plasma TV is certainly a concern, but I fail to understand why there is all the fault-finding with the ARRL.

After 1200 miles of HF mobile in a noisy Ford Ranger, nothing scares me ...

Let's all get back on the air,
73,
Mark
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on December 3, 2002 Mail this to a friend!
<It's worse than 250 uV; that's with a Quasi-Peak detector. This a detector with attack and decay time calculated to deemphasize noise that has proven in studies less irritating to radio listeners. Low-duty-cycle emissions may have a peak value MUCH higher than the quasi-peak value measured.>

Yes, although the QP detector is designed to meausure a higher level than the RMS value of the signal. It is necessary to use a QP detector because truly noiselike signals can have very high peaks, but only rarely. For absolute gaussian noise, I believe the theoretical peak is infinity. The QP detector allows one to make a consistent measurement that is a reasonable indication of the effect of the peaks on equipment and listeners. I can live with it, because for most of the signals we are talking about, we are either seeing discrete signals where the QP and RMS value is the same or very noiselike signals, where it is the average power of the signal that really impacts amateur radio.

A very few very pulselike signals may give a QP reading that is not necessarily indicative of its true effect, but on HF, this would probably be moot because the C63.4 measurement bandwidth on HF is 9 kHz, and the bandwidth limiting would really limit the pulse. In a 9 kHz bandwidth, I think the QP detector does a pretty reasonable job.

<I have LISN's and I really should hook up some of my consumer stuff and see what they put out.>

FB, but don't forget to bandwidth limit the signal in some way to ~9 kHz! You can, of course, use other bandwidths, but with care. If you are measuring a signal that is less than about 2500 Hz wide, a narrower bandwidth, such as a ham receiver, will give a good measurement of that narrow signal. If the signal is very noiselike, it can be measured in any bandwidth and corrected to 9 kHz, with some error, depending on the nature of the signal. (I know YOU know this, but the correction would be 10*log(measurement bandwidth/specification bandwidth), where the specified bandwidth is 9 kHz on HF.) For reference, a gaussian noise signal would have a QP-measured-to-average power ratio of 9.4 dB, if memory serves.

Now, this is all my understanding of a rather complex subject, so if any of youze guys are measurement engineers, feel free to jump in and help make us all smarter. Nearly everything I know about RFI has been learned from someone smarter than I am, and I ain't done learnin' yet. (And, for the record, "youze guys" is the Yankee equivalent of you all!)

Cortland, if you can set up that LISN, please do and report your results here. If they can be reasonably correlated to QP and 9 kHz (sure wish I had an ESH-30... I have to settle for the ESH-2...), we can find a home for the results somewhere on the arrl.org pages, I am sure.

73, Ed Hare, W1RFI
 
Plasma TV -- Mother of All RFI Producers  
by K9MI on December 3, 2002 Mail this to a friend!
The ARRL did a great job in helping resolve an RFI problem I had that was coming from local power lines. I had no cooperation whatsoever with the local power company, and with the ARRL's help and a letter from the FCC to our mayor, the problem was solved. Without the ARRLs representative, John, K2QAI who helped me with this problem, I would still probably have 20 db+ over S9 on 40m and lower, and S9 on 20-10m. I have no doubt the ARRL will do what they can in this situation also. If this does become a huge problem, my only fear is that Big Money will win out over Amateur Radio.

Mike K9MI
 
RE: Plasma TV -- Mother of All RFI Producers  
by KD5OWO on December 3, 2002 Mail this to a friend!
I am very big on the plasma TVs I mean they are great for veiwing and they have a wonderful wonderful picture. Still of course we do not own one and I know my neighbors won't get one so I have nothing to worry about. What I am worried about is the fact that Plasma TVs are getting to be a big thing more and more of them coming out and the more TVs made over time the cheaper the TVs get and when the TVs cost the same as a new Projection TV you will see your neighbors switching over. It is a sad thought that hams have to worry about RFI problems everytime something new comes out on the market. Some have said that the 1.2gig phones cause problems and in the 80s hams had problems with Toasters, Color TVs, and Microwaves..

I look at it like this we can not stop the production of these RFI Creators.. RFI Adapters are a good idea rather then yelling at the "innocent" TV and Applicance makers, who have done nothing to harm 'you' just doing thier jobs.. Its kind of hard to say, "Well this TV Caused problems on this Amateur radio we are not going to sell it and so we are going to loose big bucks" on the other hand what can the TV makers do to fix the problem? At this time nothing! I am sure later something good will come..

73
Steve,KD5OWO
 
RE: Plasma TV -- Mother of All RFI Producers  
by W6MRK on December 4, 2002 Mail this to a friend!
hello fellow hams, well eventhough our voice through
ham radio can be loud, dont forget the other services that use the frequencies the are plagued with the interference of the plasma tv, such as in california ( that supports a large population) who's CHP operates in the high 30's to low 40's megahertz range, and Im sure other states who's highway patrol operates in the same range also ,could pick up the same interference both mobiles and motorcycles, and base stations, when public safety and law enforcement get interfered with, then the fcc will take prompt action and start superquick investigations into the problem and correct real quick the problem, and if it takes the manufacturing companys of such interfering devices to redesign such devices , they would rather do a recall and redesign than to face federal lawsuits and other legal challenges. it may not be immediate but you can rest assured it will happen, the arrl can help back the fcc in its pursuits. when it comes to public safety and law enforcement, fcc is big brother and some good things come from it.... 73 and good luck to plasma..... mark de w6mrk
 
RE: Plasma TV -- Mother of All RFI Producers  
by KC0ODK on December 5, 2002 Mail this to a friend!
I've been very impressed by Ed's posts. So much so that I've decided to join ARRL and submitted my on-line application just prior to making this post. I'm also impressed by the level of integrity of replies to those "edgy" posts. Thanks for not taking the bait. Now on to the thread:

1 - The hobby isn't dying. The empiracal data (cited earlier in the thread) as well as anectdotal data just don't support that. Just last week I had a 10-year-old lad in the club shack and demonstrated VHF and HF. He's totally hooked and I'm certain he'll have a license soon. His interest was first sparked by the recent IMAX Space Station movie. IMHO, the ARISS project is bringing more youngsters into the hobby than we suspect.

2 - I'd be interested to know whether anybody has specific data of Plasma screens in Aircraft. By specific data, I mean make & model of monitor, aircraft type, etc. I've heard of at least one instance where a "high-profile" customer was unsuccessful in getting Plasma on a biz-jet due to safety complications. In the avionics business, we have rigourous environmental testing requirements including pressurization/decompression, vibration, temperature, HIRF, & RFI.

73s,
-Lawrence





 
RE: Plasma TV -- Mother of All RFI Producers  
by KB0NLY on December 5, 2002 Mail this to a friend!
I've heard from a few frequent flyers about the displays on commercial airlines, some say that the display is nice and clear etc.. so they must not be using any of the methods of using shielding in front of the display? I wonder further on how the display's on the airlines differ from the consumer products of similar technology. What did they do to improve the displays, how did they make them so RF tight? I read one post here that mentioned the aircraft only use VHF and above, that's not true, once beyond the normal VHF range of the tower they use HF exclusively. Especially true of HF use on the airlines is when it's a flight to Europe etc.. that goes over a ocean or sea, there isn't any towers to talk to on VHF then!

Obviously they must have either worked the problems out with the manufacturer of their displays in the early stages of development, or they came up with a add on solution to cure the problems we are seeing.

Perhaps someone needs to talk to them and find out just what the difference is? I know that on some commercial jets they use an LCD display similar to that of a Laptop computer, so perhaps not all of them are even using Plasma displays?

73,

Scott, KBØNLY
 
RE: Plasma TV -- Mother of All RFI Producers  
by KC0ODK on December 5, 2002 Mail this to a friend!
KBØNLY wrote
"so perhaps not all of them are even using Plasma displays?"

I suspect none of them are Plasma, unless somebody posts with specific make/model display & aircraft model combination that can be independantly verified. Commercial LCD panels are available with exotic (i.e. very bright) backlighting technology. This stuff is much easier to get certified in A/C.

"once beyond the normal VHF range of the tower they use HF exclusively"
Not quite true. VHF is all required for contiguous 48 states. Most narrow-body US registered aircraft have no HF. Commercial and private aircraft use VHF to contact several types of aviation facilities besides "towers". These include enroute air traffic control centers, flight service stations, unicom, and various commercial services.

KC0ODK

 
RE: Plasma TV -- DTV backstory.  
by KD5DFM on December 6, 2002 Mail this to a friend!
come on now , "om" i mean one day you also will wear that title. i am a mear puppy at 38 but i still respect the wisdom of those who has lived and delt with things longer than me . 5 wpm is not much to ask and if anyone knows the characters then anyone can do it. i do all the time and enjoy 10 wpm.
are we not all people and fellow hams no matter how old we are. some of the youngest at heart i know are above 60 ;-P .
and as far as the ham clubs my local club has increased over two fold , from 20 attending meetings to over 50 . and our club members are more than ever. how did we get there . by one welcoming new members and two a friendly , positive attitude.
now as part of the rfi , im afraid the party with the majority is also the corporate Americas best friend. you will get no where with band spectrum or rfi as long as the interest of the corporate leaders and stock market is of importance. sadly , where has the economy gone. :-(
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on December 6, 2002 Mail this to a friend!
>I look at it like this we can not stop the production
>of these RFI Creators.. RFI Adapters are a good idea
>rather then yelling at the "innocent" TV and
>Applicance makers, who have done nothing to
>harm 'you' just doing thier jobs.. Its kind of hard
>to say, "Well this TV Caused problems on this Amateur
>radio we are not going to sell it and so we are going
>to loose big bucks" on the other hand what can the TV
>makers do to fix the problem? At this time nothing! I
>am sure later something good will come..

This is all governed by FCC Part 15 rules, and those rules are intended to prevent widespread harmful interference from devices. They are lax enough so that local interference to sensitive amateur operation is likely.

Manufacturers are obligated to follow the rules. They generally do. Don't be so pessimistic about their not being willing to do more. I think that the biggest suprise I have had in my RFI work is that when I have approached industry reasonably, they have generally responded reasonably. Letters to CEOs of power companies usually get responses. Phonex and AT&T corrected problems with the 3.53 MHz PX-421 wireless modem jack, and the current modem and telephone jacks do not cause widespread interference. HomePlug and Home Phone Networking Alliance put 30 dB notches in their product lines to protect amateur radio. There are other similar projects in the works, from access PLC to VDSL.

This didn't come easy. Each of these cases involved from tens to a few hundred hours of staff work. (My wireless modem jack email folder contains over 1000 messages, plus an even greater number of sent messages in my archives).

But to a manufacturer, if someone approaches them with a problem that suggests they have to do major changes to redesign a product, that someone had better have more than a vague claim that the product will cause interference. ARRL and HomePlug and, separately, HPNA did joint field testing and demonstrated that the un-notched levels of their product would cause widespread interference, just as an example. With PLC, ARRL is working with the IEEE C63 commmittee to try to raise awareness in that industry and see what inroads can be made.

But with this type of work -- slow, cooperative and thorough documentation of a problem, coupled with reasonable expectations, these corporate giants can and do respond appropriately. I sometimes feel like I am threading eye of a needle, or walking a very narrow path, but that path appears reasonably well defined, and, by golly, the process is having a good effect.

When I was a young man, I used to tilt at every windmill. I am different now. I have picked just one and I am going to knock that sucker down!

73,
Ed Hare, W1RFI
ARRL Lab
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on December 6, 2002 Mail this to a friend!
> I've been very impressed by Ed's posts. So much so
> that I've decided to join ARRL and submitted my on-
> line application just prior to making this post. I'm
> also impressed by the level of integrity of replies
> to those "edgy" posts. Thanks for not taking the
> bait. Now on to the thread:

Thanks, Lawrence. The League will put that support to good use. Next week, I am going to take the Lab's Icom R-3 receiver down the pike to Circuit City and give a listen to the diffent TVs. It will probably be touch to sort out the really quiet ones, but that will be a good first cut at it. Let's use your membership dollars to pay for my time for that trip. (The HQ staff are not volunteers, or I would never drive to work on a snowy day like this one!). My participation here is on my own, so I will post the results here as a volunteer.

And as to the bait, I am an old rec.radio.amateur.flame pro, and, for the most part, have learned to keep my responses reasoned. I care deeply about whether the people who read my words will accept them and learn from them -- as I may learn from their responses. If I get flamish myself, that will very much detract from what I am trying to get done, and getting stuff done is more important to me that telling somebody off.

Besides,done right, one can easily point out the fallacy and illogic in someone else's argument. Folks here genearlly know who the flamers are, and they don't need me to point it out. :-)

73,
Ed Hare, W1RFI
 
RE: Plasma TV -- Mother of All RFI Producers  
by KC2GYD on December 6, 2002 Mail this to a friend!
If you believe the hobby will be dead that soon, I will buy you a tombstone for your grave. I for one refuse to believe that and will not roll over and play dead. If that makes me an "old fart", so be it.

Thanks,
Bill - KC2GYD
 
Plasma TV -- Mother of All RFI Producers  
by KG4VIC on December 8, 2002 Mail this to a friend!
My nehibor has one and they are complete JERKS! they chase me into my house every day after school their tv is causing interference with almost all the frequencies on my scanner. (I am licenced but can't afford a radio)
 
Plasma TV -- Mother of All RFI Producers  
by KG4VIC on December 8, 2002 Mail this to a friend!
My nehibor has one and they are complete JERKS! they chase me into my house every day after school their tv is causing interference with almost all the frequencies on my scanner. (I am licenced but can't afford a radio)
 
RE: Plasma TV -- Mother of All RFI Producers  
by KC0IGY on December 9, 2002 Mail this to a friend!
I too would like to salute the work of the ARRL on the RFI issue, as well as the spectrum defense issue.

I'll add something further, as a paid up member I really appreciate Ed's appearance in this forum, and I encourage the ARRL staffers to be as visible on other issues. To the rest of us, it would be an awfully good idea for all of us to spend a little more time talking about FUN with amateur radio! This is not to say that an issue such as this shouldn't get the wide ranging discussion that it has.

73,
Pierre KC0IGY
 
RE: Plasma TV -- Mother of All RFI Producers  
by KC1XU on December 9, 2002 Mail this to a friend!
It's very easy to say:

"if ARRL was worth a damn, they'd be fighting this tooth and nail...... it won't happen"

It all costs money. How much did you contribute to the ARRL's legislative fund?

KC1XU

 
RE: Plasma TV -- Mother of All RFI Producers  
by K4WTN on December 9, 2002 Mail this to a friend!
Well threes a battle plan! Just tell them (the press, neighbors friends and family ect) that there $2k+ investment will only last for 5 years or so and there display will burn out like a light bulb. Also they wont be able to replace the $1500+ screen as the mfg’s had horrible problems with them interfering with all sorts of communications equipment
( not just ham) and dropped the whole idea as it was costing the mfg’s $$$$$$$$$$$$
In battles with FCC, military, ECT.

Sometimes we need to resort to a little propaganda
 
Plasma TV -- Mother of All RFI Producers  
by WA2JJH on December 9, 2002 Mail this to a friend!

Every body is right on the money. Plasma is the worst.
The good alternative is the new TFT technology. They are just larger cousine's of the lap top. Video projectors are for the most part TFT. Just put in a 300W-1000W bulb. Quick and easy to replace.

The consumers have a choice between TFT or Plasma.
When the plasma "TUBE" or power supply burns out, though away the entire TV!

The consumers are very unenlightened about RFI.
Maybe if it is found that plasma just might interfere with commercial , public service or military communicatons...The FCC will come around.

There should be very strict emission FCC standards
on these "mother of all RFI"Consumer devices.

I know I will complian to my so called elected reps. Maybe if enough people complain, plasma will have to have better shielding.

When some one asks me should I buy Plasma or TFT, I say TFT. Yes, I do admit plasma looks slightly better.

I like the fact with a TFT, anybody can swap out a bulb or a flouresent source.

I guess a small step wold be to tell our non-ham friends and family NOT what to buy for the holiday season! You may also want to call a local TV station and "pitch" the story! Nothing is worse then bad press!
I am pitchin the story to a local TV station I used to work for. I have "pitched" before and they did Air the story a few times. Best time to a"pitch a story" is the holiday season and sweeps(Feb).

Best of seasons greetings

MIKE WA2JJH




 
Plasma TV -- Mother of All RFI Producers  
by WA2JJH on December 10, 2002 Mail this to a friend!
Good artical and timely. Hams can do something against plasma TV. Many people consult on me on electronics as gifts. Tiss the season. Fact TFT technology, the same as your laptops, are available in the same sizes as plasma. No plasma is not as bad as a spark gap transmitter, but the stray RF is unacceptable.

A fringe benefit of being a ham is that people will take your advice, over the ex-fast food worker moron at a so called electronics store. Plasma is a "tube" Tubes age. High voltage power supply caps dry out.

TFT are millons of transistors. Nice low voltage power supplies. The only thing to replace is the flourecant back light.
Cheap and easy to replace.

With projection TV's it is a no brainer. a simple 300w-1000w projection bulb can be swapped out in seconds.

Another tactic is the media. during the holiday season and sweeps is where you can "pitch" a story.
Just ask for the AE at a local TV station. I have an in.
I worked in commercial broadcasting for 20 years. I will "pitch the plasma demon" to an AE. Many things I have pitched have aired.

Yes Plasma looks slightly better than TFT. However plasmas's simply violateS FCC specs.for RFI. Farady sheilding is a must.

Tell all your friends to go TFT RATHER THEN PLASMA.
YOU WULL BE DOING A PUBLIC SERVICE
tnx BEST HOLIDAY GREATINGS TO ALL PEACE 73 de WA2JJH
MIKE NYC
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on December 10, 2002 Mail this to a friend!
>There should be very strict emission FCC standards
>on these "mother of all RFI"Consumer devices.

There are emissions limits on plasma TVs -- the same ones as for any unintentional emitter. If the rules need to be changed, don't think in terms of plasma TV, think in terms of all emitters.

15.109 sets limits on the amount of energy below 30 MHz that unintentional emitters can conduct out the device's AC line cord. The limits are at a level that would typically result in about S9 noise to nearby amateur receivers.

15.209 sets limits on the amount of radiated energy about 30 MHz. On VHF, the legal limits would be about S7 or to to a nearby 2 M ground plane.

There are no radiated emissions limits on HF for unintentional emitters. They operate subject to a requirement that the manufacturer use good engineering practice and the operator not cause harmful interference. Would complying with the FCC limits for intentional emitters be good engineering practice? I am sure the FCC would think so. The legal limits for intentional emitters would result in S9+ interference to nearby amateur stations.

Think the rules need to be changed? Maybe. To give us complete protection would require about 50 to 75 dB of improvement. Are you willing to pay lots more for every piece of equipment you buy to reach that level of protection? What percentage of plasma TVs do you think ended up near an amateur who is using the part(s) of the band(s) that might be affected?

The existing Part 15 rules are meant to prevent most cases of harmful interference. Amateur radio has rules on harmonics and other spurious emissions that are intended to prevent most cases of harmful interference. Both have a further requirement to correct interference from spurious emissions(or fundamental emissions in the Part 15 case). Do you think that Part 15 should be regulated to the same degree of protection as amateur radio must offer its neighbors.

Let's put this into a different perspective. A device that is generating the legal limit for intentional emitters on 3.5 MHz has a transmit power of about .0027 microwatts (assuming 0 dBi antenna gain). On HF, at 500 watts an amateur station is permitted a harmonic or spurious emission of 50 milliwatts. We are permitted about 70 dB more harmonics on the channel that TV is tuned to than the TV is permitted to transmit on our channel. If you add the 50 dB more that would be required to protect against any possible interference, if amateur radio were treated equally with Part 15, our transmitters would have to have:

-40 dB (existing FCC spurious for amateur)
-70 dB (to get ham to be Part levels)
-50 dB (to get Part to never interfere)

-150 dB would be needed unconditionally ensure that no amateur transmitter ever intefereed with any nearby equipment. Even if you add back the 50 dB, perhaps to account for the fact that TVs are not as sensitive as ham equipment, we have to be careful what we ask for when the scales are already so very unbalanced in our favor.

Just some food for thought and more fodder for the discussion. :-)

73,
Ed Hare, W1RFI
 
Plasma TV -- Mother of All RFI Producers  
by WA2JJH on December 13, 2002 Mail this to a friend!
Yes, True OUR RADIO'S may cause interference. However when the WORLD TRADE CENTER, went down ham radio's provided a lot of emergency communication. Ham radio has provide emergency communication for many years. A plasma TV cannot make the same claim!

So that is my food for thought. Again TFT/Bulb has just about zero emission compared to the more expensive Plasma.

OH, and to that kid with the expired license that called us all "OLD FARTS", I am 42 years young. I can still break a wooden board with my fifth metacarple or my elbow.
 
RE: Plasma TV -- Mother of All RFI Producers  
by W1RFI on December 13, 2002 Mail this to a friend!
> OH, and to that kid with the expired license that
> called us all "OLD FARTS", I am 42 years young. I
> can still break a wooden board with my fifth
> metacarple or my elbow.

When the teenagers were still living at home, their friends used to pick on me for being old. One day, I confessed that it is indeed tough getting old. I gave them an example: If I spend 10 hours outside on a Saturday splitting firewood, by the end of the day, I am pretty sore. And, being old, when I wake up the next day to do it all over again, it takes a bit of time to get the kinks out. They then looked at a piled mound of about 3 cords just out in the back yard and decided that this might be a good time to change the subject. :-)

Here it is over 10 years later and I am still heating completely with wood. The young fellow is more than welcome to come over my house and show me how young folks can split firewood for two days running without breaking a sweat...

73,
Ed Hare, W1RFI
 
RE: Plasma TV -- DTV backstory.  
by N2YPH on December 17, 2002 Mail this to a friend!
KB3DVS - Thanks for posting the clarification, very well written, better than I could've done it.

I wonder - What percentage of plasma TVs are *THIS* bad? One person posted that they had no problems at all with their plasma display.

I wonder if the popularity of LCD displays for PCs will eventually drive LCD prices down below that of plasma for the largest of displays. (They're coming close... I've seen a few LCD widescreen TVs of the same order of size as plasma displays, at only 10-20% more expensive.)

LCDs typically cause far less RFI - In fact, I've often seen using an LCD monitor (and even going "all the way" to a laptop) recommended as a good solution for PC-originated RFI.

We won't see OLED displays anytime soon due to the liftetime issues of red/blue OLEDs... Green OLEDs are competitive, red/blue aren't there yet. :(
 
RE: Plasma TV -- Mother of All RFI Producers  
by WR8Y on January 22, 2003 Mail this to a friend!
test again...
 
3-output "Guest" boat Battery Charger, M  
by WB5WPA on November 12, 2003 Mail this to a friend!
Add this device to the prodigious RF-producer list: The "Guest" (AKA "GuestCo" in some circles) Model 2623 3-output (3 independent batteries: 3-12V or 1-12V and 1-24V 'stack'), 25 Ampere, on-board boat Battery Charger.

These potted "high-frequency switching technology" chargers are quite capable of putting out over half a dozen S9+ signals (with a number of those at +30dB over S9) in the 80 Meter ham band (as indicated bt my Yaesu FT-101E series HF rig). Other 60/120 Hz 'hash' components can be heard all throughout the HF spectrum up through 30 MHz - and this is with a "Corcom" brand AC Line Filter in-line with a short cord to the AC mains!

Initially, I thought the power company was at fault ... wrong-o! It was my neighbor and his bass boat! I can now tell when he's out fishing or back charging his 24V trolling motor 'stack' and keeping his starting battery 'topped off'.

These chargers, as indicated in the user manual are Part 15 "Class A" certified devices. If this charger indeed meets this 'looser' spec (than the Class B devices) for conducted emissions - the devices in this category are *indeed* noisy ... there are models out there (like those made by Charles Industries as in their 5000 series which are Class B certified and advertized as "Virtually no RFI or EMI interference - exceeds FCC/Class B requirements" but at additional cost over what the Guest charger sells for) that are more suitable for a residential neighborhood.

de WB5WPA Jim
 
RE: Plasma TV -- Mother of All RFI Producers  
by KD7YVV on November 30, 2003 Mail this to a friend!

>RE: Plasma TV -- Mother of All RFI Producers Reply
>by KG0D on November 28, 2002 Mail this to a friend!
>Hey there, N5SCP - you need a good @$$-kicking!

>REAL hams are concerned about this issue. I'm sure >that you as a big shot, so called "tech plus" (God >that makes me laugh!!!!) won't experience much >interference on your two-meter handheld radio (probably a Radio Shack model anyway), since all you >do is hang out on your local repeater, >trading "handle here is" and "10-4's", so butt out >and let the real hams who you should be respecting >speak on this issue.

>By the way "Josh", why don't you turn off your >playstation and crack open a book! Maybe Mommy will >read it to you...



David,

Your reply certainly doesn't reflect the best portrayal of a "Real" Amateur.
I was recently licensed 10 days ago.
I suppose the time I put in studying for my license
and the research time I've put into getting a proper
radio and learning the operation and protocols of
the local K7NWS repeater are a complete waste of
time and effort eh?
It seems you should read a book David, one entitled
Now You're Talking, latest edition, and remember
what it was like when you were first starting out.
You'll probobly find reference in there to something
called the Amateur's Code....
The one written in 1928 by W9EEA....

The Radio Amateur is
CONSIDERATE
LOYAL
PROGRESSIVE
FRIENDLY
BALANCED
PATRIOTIC

Just a thought.....

--Deeply Shrouded & Quiet
--Kilo Delta Seven Yankee Victor Victor

 
Brand: Terminator Scooter Battery Charger  
by WB5WPA on May 31, 2004 Mail this to a friend!
The electric scooters sold here:

http://www.terminatorscooter.com/

utilize chargers branded as "Made in China".

These chargers, furthermore, carry *no* FCC label as is currently required under the law per FCC Part 15.

Furhermore, the manuals for the chargers also carry no required FCC Part 15 notices.

These power supplies/switchmode battery chargers *will* generate RFI that *will* affect your operations from 80M (didn't check 160) through at least 20M ... the strongest RFI seems to be from about 5 through 7 MHz at least - every 50 to 60 KHz as one of these guys details here:

http://lists.contesting.com/archives/html/RFI/2004-01/msg00059.html

I noticed relatively little RFI in the AM Broadcast band except for a 'dirty carrier' around 700 KHz - probably the operating frequency of this switch mode charger.

The charger that affected me was one street over and about 7 or eight houses up; we *do* share common underground AC power utilities though the power distribution network in the back alley easement - this would seem to *aid* the transmission of the offending noise from these chargers throughout the neighborhood.

The gentleman I contacted on premises was quite receptive; my opening line was "have you been having any TV or radio inteference problems lately" to which he replied: "yes".

Within two minutes we had it islolated to the Terminator Scooter Battery Charger ... the charger outputs about 28 volts for charging 2 - 12 V batterys in series located inside the scooter.

The equipment I used to track this source down, as always, was a Sears 4-band AM-FM-SW receiver circa 1968 (I still have the original Sears shipping label and the radio's manual as well as 'shop' repair schematic).

The secret to DFing these 'sources' is to use that radio on the 2 - 6 MHz band where the ferrite loopstick antenna is still 'active' and DF when close to the offending source by using the 'nulls' seen of each end of the loopstick antenna ... I walked a lot of streets in the area until finally 'landing' this one - that 5 MHz energy travels blocks in all directions, and again, this was with *underground* utilites - the mere fact that we use two different step-down xformers doesn't seem to be an impeding factor in the promulgation of this noise down the 'power line' ...

Jim WB5WPA


 
RE: Plasma TV -- Mother of All RFI Producers  
by HEYMAW on June 15, 2004 Mail this to a friend!
Another question, Does anyone know if Plasma TV's interfere with other INFRARED devices?
 
RE: Plasma TV -- Mother of All RFI Producers  
by XR11 on November 16, 2004 Mail this to a friend!
Anyone follow up on this plasma TV intereference thing?

Also, note the article below: "TV sets off search and rescue satellite" maybe now something will be done.

One thing that is curious, the FCC officials quoted in the story sounded as if this is the first they have heard of RFI problems from the new TVs.

http://www.space.com/spacenews/businessmonday_041025.html

 
Plasma TV -- Mother of All RFI Producers  
by KB0GU on November 21, 2004 Mail this to a friend!
Well I wonder if a plasma TV moved in near me, all of a sudden I am getting this raspy signal across the band as the author of this article describes. I have no sound bite to compare to yet but it sounds like a phaser off of Star Trek. On the psk waterfall it looks like a rain shower about a Kilocycle wide and it tends to drift up or down a bit with time like rain being slowly blown across a field. When centered in the passband of the TS870 it gives an S9 signal on 7.070 +- 1 Khz. I have a Radio Shack DX100 shortwave receiver upstairs and it shows very strong signals all up and down the shortwave bands. My plan is to take a pocket shortwave receiver and explore the neighborhood, but given the statement above that the signal could be from as far away as a quarter mile there is a lot of homes in that circle around my suburban home. So far I can avoid the signal by moving up or down from it by a khz but it does tend to slowly creep around and can end up in the pass band during a long winded qso. In short it is quite annoying. Guess I am wondering if my transmit signal is getting into it as bad as it is getting into my receiver?
Best Regards
 
RE: Plasma TV -- Mother of All RFI Producers  
by KB0GU on November 21, 2004 Mail this to a friend!
Oh, yes - in reading all these replies in light of recent history and the date of their posting I could only sigh thinking about the recent approval the FCC gave for BPL, which was my first thought when I heard this noise, maybe it is BPL I thought. Well no it is not modulated like BPL would be. Oh well, guess I will live with it and work around it.
 
RE: Plasma TV -- Mother of All RFI Producers  
by HETHERT on June 8, 2005 Mail this to a friend!
Thanks for bringing up a very important point- your last one. What will all this RFI be doing to human & pet health? Worse yet the cable companies are marketing HD packages hot & heavy. By the way, all analog bcstg stops by 2015. All major networks are to be in the digital/HD fold by 2008. Expect the next 3 Xmas's to fuel up this problem in a very big way.
I have a new company marketing ferrite beads to consumers, who are concerned about all this leakage. I am very sad to say- business is definitely looking up!
Try to "educate" your non-Ham & non-tecnically oriented neighbors to this problem. Let them know there are work arounds & solutions. It's much easier to get understanding & cooperation from ppl who have the knowledge of the problem- then from those who don't have a clue. Hint to the uncooperative, that they are not only causing radio interference, for your Ham- they are probably causing future cancerous growths amongst their own family members-maybe even themselves!
I can actually foresee future "airwave wars" taking place in many American communities- probably globally as well. Instead of "road rage wars", an already incredibly stupid reason to shoot your neighbor- now ppl will lash out in a state of rage- over the local airwaves.
I am very concerned that all this additional RFI, will cause a huge increase in future populace incedence of malignant adenomas(cancerous tumours.)
 
Plasma TV -- Mother of All RFI Producers  
by ON4UN on November 3, 2005 Mail this to a friend!
About 1 year ago I bought a JVC Plasma TV. I checked it out with my 160m and 80m portable receiver with DF antenna (ferrite) and the noise generated at about 3m (10 ft) in the same room was no worse than from any regular TV. I have been DX-ing on all bands (and contesting) without any noise problems from it at all.In practice I cannot hear whether the TV is on or off on any band, and can work the sual stuff on the low bands...
I know about a case where a Samsung Plasma TV caused S9 interference almost 1 km away (ask ON4WW).
To me it looks like there are brands that are well shielded/filtered and others (probably the cheaper ones)that cause all the problems.
73
John, ON4UN
 
Plasma TV -- Mother of All RFI Producers  
by ON4UN on November 3, 2005 Mail this to a friend!
About 1 year ago I bought a JVC Plasma TV. I checked it out with my 160m and 80m portable receiver with DF antenna (ferrite) and the noise generated at about 3m (10 ft) in the same room was no worse than from any regular TV. I have been DX-ing on all bands (and contesting) without any noise problems from it at all.In practice I cannot hear whether the TV is on or off on any band, and can work the sual stuff on the low bands...
I know about a case where a Samsung Plasma TV caused S9 interference almost 1 km away (ask ON4WW).
To me it looks like there are brands that are well shielded/filtered and others (probably the cheaper ones)that cause all the problems.
73
John, ON4UN
 
RE: Plasma TV -- Mother of All RFI Producers  
by KA2UUP on December 7, 2005 Mail this to a friend!
Just bought one of the things. Boy, do I REALLY have a problem now. 20 meters is the worst with a swishing noise every 15-20 kHz.

I guess guess I'll have to tell the wife to shut down when I operate. Wish me luck!!!

Bert, KA2UUP
 
RE: Plasma TV -- Mother of All RFI Producers  
by WA2KBU on January 22, 2006 Mail this to a friend!
>Any way, I offered to replace the device with one that was not in the middle of 80 meters. I was told to "get lost".

I called CW with 1500 watts on the center of that frequency every night. I managed to have a number of nice CW QSOs despite the signal level from the neighbor. About a week later that signal was gone. <

Sometimes Charlie homeowner just doesn't get it, I am glad to hear that you had so many 599 qso's on that 80 meter frequency! LOL

Bob K8NY
 
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