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Author Topic: W1AW QRMing 80m PSK...  (Read 2887 times)
WB4IUY
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« Reply #15 on: January 16, 2010, 04:56:29 PM »

Thanks for the feedback, Rick. I'm playing on 80m PSK31 right now, an using the dual PBT is helping somewhat. I think I'm gonna get a narrow filter and put it in the SSB filter bank in place of the 1.8khz narrow SSB filter...I seldom (if ever) use that one.

73
Dave WB4IUY
www.WB4IUY.net
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N4KZ
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« Reply #16 on: January 18, 2010, 11:45:07 AM »

Split your VFOs with one on SSB -- for transmitting PSK31 -- and the other set for CW to use your CW filter. You must do some experimenting on the receive tuning but this system works fine for rigs that lack digital mode filters.

73, N4KZ

PS -- I use my Pro 3's 50 Hz digi mode filter when on PSK31 and receive just one signal at a time. Watching the whole waterfall is pretty and interesting visually but you're giving yourself a serious receive handicap. By receiving just one signal at a time, I vastly improve the receive S/N ratio and those weak signals pop up out of nowhere! Suddenly, getting really good copy on very weak signals is easy. And QRM is a thing of the past.
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W7ETA
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« Reply #17 on: January 19, 2010, 02:34:29 AM »

Since you've been licensed since the WN era, why do you equate operating your station with the same importance as the ARRL broadcasting bulletins and code practice on a SKED to benefit hams world wide?

Since we don't recognize how your transmissions could be important enough for the ARRL to monitor a frequency you like to use, and then wait for you to be done, why don't you enlighten us about how important you are.

73
Bob
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WB4IUY
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« Reply #18 on: January 19, 2010, 06:22:22 PM »

Bob, I didn't think it was about who was more important than someone else, but rather not firing up on a frequency that was occupied. I must say, as an "old-timer" I've learned a lot from this thread...

#1 - I picked up a few ideas on how to better operate PSK in crowded conditions

#2 - One can transmit on a busy frequency if one has been doing so for a long time

#3 - The "Do as I say, not as I do" rule applies if you're a  large organization that publishes a digital bandplan and then continues to operate outside of those guidelines

#4 - There is no need to check to see if a frequency is busy prior to operation if one is more important than those who might be currently using said frequency.

Dave WB4IUY
www.WB4IUY.net
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W7ETA
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« Reply #19 on: January 20, 2010, 01:08:35 AM »

Aaaaaaaw.  Come on Dave.  Time to fess up!

You ain't really one of those thinkin whatever you're doing is more important than The League starting on time?  Or that someone there is actually sitting around listening to every frequency they broadcast on, so that they can wait 'till all the frequencies are clear?

Just imagine if they interrupted your Q to announce that everyone should just hang around till Dave or the other op is done?

Do you really wanna be known as THAT! op?
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K1MMI
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« Reply #20 on: January 20, 2010, 01:21:42 AM »

I understand and appreciate the issues with a station not checking a frequency before transmitting.

A while back the CEO of ARRL wrote a letter explaining why they operate W1AW as they do. The ARRL is the place to contact to discuss W1AW transmissions.
I'm just trying to share information I've learned over the years and anyone can take my comments for whatever they are worth or not worth.

W1AW transmits bulletins on 6 or more transmitters at the same time. Having 6 employees to monitor 6 frequencies before beginning a transmission is not economically practical.

My understanding is the FCC rules were modified to give a bulletin station the right to transmit on multiple transmitters at the same time, without listening on the frequencies, provided they had a published schedule of all their transmissions.

To me, W1AW bulletins are in the best interest of Ham Radio because they are intended for a very large number of people and I'm just one person. I know when a W1AW bulletin is scheduled and it's not a problem for me.

Years ago I would complain when someone would politely ask me to QSY because a NET was coming on. I'm not a NET person but when I know 20-25 stations may be checking into a NET I have no problem QSYing these days.

Some Hams may choose to have a turf war and refuse to QSY for a NET but I can deal with QSYing because it seems better for two people to QSY rather than make it a problem for 25 people.

When I operate I try to use Common Sense and follow the rules and the spirit of the rules. Nothing is perfect but I believe W1AW Bulletins and NETs do far more to promote Ham Radio in a positive way rather than bickering over turf wars.

Ed
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WB4IUY
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« Reply #21 on: January 20, 2010, 03:53:30 PM »

My biggest grumble wasn't so much that they don't listen before they transmit (though I've commented on it), as I had not thought about the fact that they transmit on multiple frequencies at once. I'm sure that is quite a task to manage and helps a lot of hams around the world.

I was more aggrivated by the fact they they are transmitting a high power CW signal in a tiny sliver of the band that was even promoted by themselves as being as for PSK-31 for the last several years, and is mostly used by low power transmitters. I realize that CW is legit anywhere, but the ARRL themselves  promotes the use of a bandplan to maintain harmony among modes of operation.

BTW, I've received a message from the League that they are looking about for an 80m operating frequency outside of the PSK sub-band, so they are aware of the issue and working to do something about it.

I've tinkered around in my rig, as a result of feedback in this discussion, and found that I can use a CW filter as an auxillary filter in SSB mode. I've already ordered a tight filter for the SSB mode, specifically for PSK in the USB mode. This will help my personal operations via my 756. The ARRL moving, as they indicated that they are looking to do, will help others who use PSK in the PSK sub-band.

Dave WB4IUY
www.WB4IUY.net
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N2EY
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« Reply #22 on: January 20, 2010, 05:09:19 PM »

WB4IUYI writes: "I was more aggrivated by the fact they they are transmitting a high power CW signal in a tiny sliver of the band that was even promoted by themselves as being as for PSK-31 for the last several years, and is mostly used by low power transmitters. I realize that CW is legit anywhere, but the ARRL themselves promotes the use of a bandplan to maintain harmony among modes of operation."

Some fun facts:

W1AW code practice/bulletins are transmitted simultaneously on 8 different frequencies. The schedule is published in QST and is on the ARRL website, and doesn't change much from year to year.

The total time of CW bulletin/code practice is less than 34 hours per week, which is about 20% of the time (there are 168 hours in a week). Weekends are usually free.

Except for the WW2 shutdown, the Maxim Memorial station has maintained a regular published schedule of bulletins and code practice operation since 1936. (W1AW was H.P. Maxim's call)

For US hams, PSK31 is legal on any frequency from 3.5 to 3.6 MHz, as long as the entire signal is inside those limits and the licensee's license allows it.

So why is PSK31 operation clustered so close to W1AW? Thereby hangs a tale....

Back when US TV was analog, every NTSC color TV set had a 3579.545... kHz crystal inside. Amateurs interested in "glowbugs" (simple tube rigs) and QRP operation often salvaged those crystals from old TV sets for use in their rigs. 3579 became a popular glowbug frequency.

3581-and-a-fraction became the W1AW frequency because a simple direct-conversion receiver using a 3579.545 kHz xtal as a BFO would be tuned perfectly to W1AW. Also, amateurs using simple and uncalibrated receivers could find W1AW if they built a simple oscillator using one of those crystals.

Then in 2001 there appeared a rig called the "Warbler". It was a single-board QRP PSK31 rig designed for computer control. Its front end filtering was a ladder filter made from those same crystals, which limited the coverage to a few kilohertz right near 3579. And since the Warblers were there, it became a watering hole for all PSK31 operation, even by hams with rigs that could go anywhere.

And the glowbuggers were pushed off 3579. But W1AW stayed, in part because it effectively marks the edge of the band.

The Warbler concept was radical in that the rig itself is fix-tuned; there is no frequency adjustment at all. The rig simply inhales a couple of kilohertz of the band and converts it to audio, and then the sound card and software of the connected computer decide which signal to decode. Interesting concept and simple, but not the best for dynamic range nor QRM reduction, because ANY strong signal will take over the passband.

Since a PSK31 signal is only a few dozen Hz wide, it could be used with very sharp filtering in a tunable rig. But that means you have to tune the *rig*, not the computer, and that you see a much smaller slice of the band on the waterfall display.

It seems to me that the solution is at least three-fold:

First, there's no reason VFO-equipped PSK31 stations can't move a bit farther away from W1AW when it is in operation. The schedule isn't a secret.

Second, stations using rigs other than Warblers can use better filters, turn off the AGC, turn down the RF gain and do other things to improve the dynamic range of their receivers.

Third, W1AW can move someplace else. But where?

WB4IUY: "I've tinkered around in my rig, as a result of feedback in this discussion, and found that I can use a CW filter as an auxillary filter in SSB mode. I've already ordered a tight filter for the SSB mode, specifically for PSK in the USB mode."

There you go. Will it also work in LSB mode? That way, you could zero-beat W1AW.

This raises a question: Is anybody still using the Warbler rigs?

73 de Jim, N2EY
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N3OX
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« Reply #23 on: January 20, 2010, 10:17:41 PM »

This raises a question: Is anybody still using the Warbler rigs?

That raises a further question.  How much should we shuffle things on the bands to accommodate rigs with essentially no selectivity?  If I'm on 80m CW and all I have is a SSB filter, I have to suffer with it until I get a CW filter.  I have no expectation that stations will remain weak and un-problematic +/- 1.5kHz from my operating frequency.

By the way, here's another important operating tip from G4ILO, when you really want the panoramic tuning:

http://www.g4ilo.com/2009/05/psk31-with-agc-off.html

Turn off the AGC, turn the RF gain way down.  Put the weakest signals down closer to the sound card noise floor and just make sure the strongest don't distort.  Maximize the dynamic range of the system... and you can't pump the AGC if the AGC ain't on :-)

You probably can't fix your W1AW "problem" this way.  You probably need that selectivity.  For that, the CW filter is *perfect.*  It is the answer.  It may be that the ARRL will move W1AW anyway: they did that with the 160m station to help out the 160m weak signal guys.

 But that will still leave the "problem" of stations who put out good loud signals on PSK31.  Insisting on weak signals everywhere inside a chunk of spectrum that accommodates a hundred PSK31 passbands is not really the right solution.  You can't tighten selectivity too much further than a basic CW filter without getting fancy, so dialing in one super weak PSK31 signal 100Hz away from a super loud one is not going to happen.  But using that CW filter almost all the time is not insane.  I think that viewing panoramic tuning as an unalienable right of PSK operation is just a recipe for angry ops and bad blood against people who have the audacity or "bad" propagation luck (!?!?) to put out a loud signal.

Except possibly to accommodate special homebrew projects, like the Warbler, we should encourage the use of selectivity when the problem calls for selectivity, not necessarily lowering of power output or moving loud stations many kHz away... those are strange responses to a simple problem.

73
Dan
















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73,
Dan
http://www.n3ox.net

Monkey/silicon cyborg, beeping at rocks since 1995.
NI0C
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Posts: 2383




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« Reply #24 on: January 21, 2010, 05:16:31 AM »

N2EY nailed it with these sentences:

"there's no reason VFO-equipped PSK31 stations can't move a bit farther away from W1AW when it is in operation. The schedule isn't a secret.

73,
Chuck  NI0C

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K1MMI
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« Reply #25 on: January 22, 2010, 12:50:23 AM »

WB4IUY writes:  "can't imagine this QRM from the league as being much more than _noise_ to most hams,
 performed so we know they're still there and actually doing something. "

In Massachusetts the W1AW transmissions are extremely strong and provide a very reliable data source.

In the 60's I would listen to W1AW CW transmissions to boost my CW receiving skills.

In the mid 80's I wrote assembly language progams to decode CW and RTTY transmissions on my 1 Mhz Radio Shack Color Computer. To debug and test a computer program you need a very reliable data source and W1AW transmissions was the main data source to get my
programs to work.

Over a year ago I wrote a Windows program to send and receive RTTY. W1AW RTTY transmissions was the main data source to test and debug my program.

Recently I've been listening to W1AW 30/35 WPM transmissions.

With over 700,000 Hams in the USA I suspect there are a large number of Hams who appreciate
these W1AW transmissions. I expect these W1AW transmissions to continue as long as the ARRL
receives feedback from Hams who see these transmissions as having value. If the Ham Community
tells the ARRL there is no need for these W1AW transmissions the ARRL will discontinue them.

In Massachusetts when I use HamRadioDeluxe and my sound card to receive PSK31 transmissions on
80 meters I'm lucky to hear two stations using PSK so I wonder how many PSK stations are bothered
by W1AW transmissions? But in other parts of the USA there may be a lot of PSK activity and W1AW
transmissions are a big problem.

Ed

PS - My understanding is the FCC rules were modified to special case the ARRL/W1AW situation where the ARRL represents 700,000 Hams. If my understanding is correct the W1AW transmissions are in full compliance with the FCC rules.
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N2EY
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« Reply #26 on: January 22, 2010, 04:31:58 AM »

I googled "Warbler PSK" and found that the Warbler kit is still available from Small Wonder Labs. Only $55.

The rig covers approximately 1 kHz of 80 meters, which is more than enough for several PSK31 signals if they're clean.

I found it particularly interesting that there's a screen shot of the waterfall display taken *while W1AW is in operation 2 miles away* (!). The Warbler copies right through it. (The trick is that W1AW is zero beat).

If a ham using the simple Warbler 2 miles from W1AW's legal-limit CW can have 100% PSK31 QSOs, what's the problem?

73 de Jim, N2EY

One more thing....

Why isn't PSK31 allowed in the US 'phone subbands? Yes, I know it's FCC rules, but why do those rules exist?
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WB4IUY
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« Reply #27 on: January 22, 2010, 04:49:15 AM »

"Why isn't PSK31 allowed in the US 'phone subbands? Yes, I know it's FCC rules, but why do those rules exist? "

I didn't know that..it's actually a rule to not allow PSK in the phone band? ...Ya learn something new every day :-)

Dave Wb4IUY
www.WB4IUY.net
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N2EY
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« Reply #28 on: January 22, 2010, 06:45:21 AM »

WB4IUY: "it's actually a rule to not allow PSK in the phone band?"

In the USA, FCC part 97 does not allow any 'data' modes in the 'phone/image subbands on 75, 40, 20, 17, 15, 12 and 10 meters. 160 and VHF/UHF have no such restriction, and of course 30 has no 'phone subband and the five channels at 60 meters are USB only.

No PSK31, no RTTY, no PACTOR, no AMTOR, no Winlink, etc. Only CW, voice and image modes like SSTV.

I don't know why the US rules are like that, but they are.

Check Part 97 (available free from the ARRL website and elsewhere) and you'll see.

73 de Jim, N2EY
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N2EY
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« Reply #29 on: January 22, 2010, 08:06:17 AM »

N3OX asks: "How much should we shuffle things on the bands to accommodate rigs with essentially no selectivity?  If I'm on 80m CW and all I have is a SSB filter, I have to suffer with it until I get a CW filter.  I have no expectation that stations will remain weak and un-problematic +/- 1.5kHz from my operating frequency."

Exactly!

One thing that *can* be done is for wide and narrow signals to each have their own subbands.

N3OX: "Turn off the AGC, turn the RF gain way down.  Put the weakest signals down closer to the sound card noise floor and just make sure the strongest don't distort.  Maximize the dynamic range of the system... and you can't pump the AGC if the AGC ain't on :-)"

Adaptation of an old, old CW operating trick from back when most receivers' AGC didn't work on CW.

The problem is that many of today's hams aren't used to operating without AGC, and manually controlling the RF gain.

N3OX: "You probably can't fix your W1AW "problem" this way.  You probably need that selectivity.  For that, the CW filter is *perfect.*  It is the answer."

It's *an* answer. Here's another:

On the Small Wonder webpage they show and sell the Warbler kit. There's a screen shot of a QSO going on when W1AW is in operation 2 miles away (!). Solid copy because that Warbler is set up with W1AW zero-beat, so all you see are the keying sidebands.

Per the website, the Warbler only inhales about 1 kHz of the band, making it narrower than an SSB filter.

I may have to get me one of those things...

N3OX: "It may be that the ARRL will move W1AW anyway: they did that with the 160m station to help out the 160m weak signal guys."

And of course the question is: where do they go that they don't step on somebody else?

N3OX: "But that will still leave the "problem" of stations who put out good loud signals on PSK31.  Insisting on weak signals everywhere inside a chunk of spectrum that accommodates a hundred PSK31 passbands is not really the right solution.  You can't tighten selectivity too much further than a basic CW filter without getting fancy, so dialing in one super weak PSK31 signal 100Hz away from a super loud one is not going to happen.  But using that CW filter almost all the time is not insane.  I think that viewing panoramic tuning as an unalienable right of PSK operation is just a recipe for angry ops and bad blood against people who have the audacity or "bad" propagation luck (!?!?) to put out a loud signal."

I agree 100%. W1AW is far from the worst problem because we know where and when they will fire up.

But expect things to get worse. One of the selling points of SDRs is the idea that you can watch the whole band on a panoramic display, regardless of mode, and tune by pointing and clicking. Works great until a rock-crusher comes on the air and puts phantom signals all over the place.

73 de Jim, N2EY
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