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Author Topic: a 7500 watt 11 METER CB OP?  (Read 19613 times)
N5LRZ
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« Reply #15 on: August 31, 2009, 03:25:12 AM »

Re DRN...

No money no problem...

Do what the IRS does, or should I say formerly did.  Seize their property (home, etc) and sell it.  Garnish their income to the extent the law allows.
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N7ZM
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Posts: 131




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« Reply #16 on: September 01, 2009, 05:59:21 PM »

This guy is just blowing smoke.....there is no mobile that can do that much power without Tubes, and can you imagine the power supply needed for that, all in a mobile, come on........or maybe he's using one of those inaccurate MFJ meters. Wake up and smell the roses. This guy did what he was looking for, he got us writting about it.
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K9FON
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Posts: 1012




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« Reply #17 on: September 04, 2009, 11:15:38 AM »

7500 watts. Hmm i guess he feels the need to make up for the lack of "something else" much like the bozos with the loud mufflers on motorcycles and trucks. I just dont understand the rationale of people with this kind of mindset. I really dont get it............
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N2EY
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Posts: 3895




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« Reply #18 on: September 04, 2009, 02:51:37 PM »

There are ways to get that much power in a mobile. I don't do this sort of thing, but I have read about it, and it's not as impossible as it may seem.

The first step is that the regular 12 volt power system isn't used for the amp. It's used for the driver and low-power stuff only.

For the big amp, a completely separate 24 or 48 volt system - or systems! - is/are installed, with big alternators and batteries. This means a big vehicle, like a Suburban, van, or pickup-with-cap, but that's part of the game.

At 50% efficiency, 7500 watts out means 15,000 watts in. 15,000 watts sounds like a lot but it's only about 20 horsepower, so even a small V-8 is more than enough. At 48 volts, 15,000 watts is 312.5 amps, which is a lot but not unmanageable with heavy-duty components, particularly if you have more than one system.

(What passes for "high power" in radio is really not that much in other fields. Back when AM broadcasting was king, mighty WLW ran 500,000 watts, and became a legend. 500 kW sounds like a lot, but it's only 670 horsepower.)

The second step is that the amp is modular, consisting of several smaller amps connected with splitter/combiners. These can be as simple as quarter-waves of 75 ohm coax. Each amp module may contain quite a few transistors, but since quality of signal isn't a consideration, matching isn't a big concern.

The third step is low duty cycle and not caring about how clean the output is. The system need only work long enough to get a meter reading. During a max-power test, both the batteries and alternators power the amp, too.

There are RF power transistors that can do 150 watts output per pair all day long, so in short-term redline operation you might get 250 watts from a pair. 8 of them in an amp will give 2000 watts, so you chain up 4 modules and get about 7500 watts after all the combiner losses and such.

The final trick is that the quoted power levels are often peak watts, not average.

73 de Jim, N2EY
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N2EY
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Posts: 3895




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« Reply #19 on: September 04, 2009, 03:02:36 PM »

"There is serious $$$$$ to be made here."

Well, yes and no.

First off, the FCC doesn't get the fine money. It goes into the general fund, and FCC never sees a penny of it directly.

Second, the wheels of justice turn slowly, and it may take lots of manhours and dollars to get a serious fine. The cost of prosecution may and probably will exceed the fine recovered.

Third, there's enough other crime out there that devoting serious resources to something like a rules violation can make an agency a target for serious criticism.

The real questions are:

Who is complaining?

How are they being hurt? (interference to a legal operation is a good one)

What evidence exists?

If somebody is blasting ten kW of 27 MHz RF from a mobile out in the country during a sunspot minimum, and nobody complains of interference, why should FCC spend a lot of resources on it when there are hams and others complaining daily about power-line noise, plasma-TV noise, intruders in the bands, unlicensed folks on public-service frequencies, defective TV sets leaking RF on EPIRB frequencies, false distress calls on VHF marine channels, etc.?

73 de Jim, N2EY
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NO2A
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Posts: 801




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« Reply #20 on: September 04, 2009, 05:34:08 PM »

Jim,i don`t care either if they want to do that stuff on 27 mhz,but the problem starts when they eventually find their way up to 10 meters and sometimes 12 meters. I`ve heard the cb`ers on with their "roger beep" radios and it just keeps getting worse. There have been reports of taxi drivers in NY city running radios like those on 10 meters illegally. (and other businesses) as well.
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N2EY
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Posts: 3895




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« Reply #21 on: September 05, 2009, 04:30:52 AM »

NO2A:

I agree 100%; what cb folks do on their channels is one thing, but when they leave those channels and go on the ham bands, it's something else.

This isn't a new thing, either. It's been a problem since at least the mid-1970s. It's why Novices and Techs have 10 meter privileges.

Personally, I'd rather have the FCC use its limited resources to go after intruders in the amateur bands rather than the occasional superpower cb setup.

But that's just me.

73 de Jim, N2EY
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K9FON
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Posts: 1012




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« Reply #22 on: September 05, 2009, 07:42:22 PM »

As long as the FCC is lax on rule enforcement the CB ops will do whatever they feel like no matter what. The day the FCC dropped the licensing requirments the CB band went down the stool, and we are dealing with what we have now..........
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N5LRZ
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Posts: 0




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« Reply #23 on: September 06, 2009, 08:10:53 AM »

The FCC could just pull the plug and shut down the CB Band entirely by taking it away from the CB people and giving it to commercial, military, or whomever.
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K2NRC
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Posts: 19




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« Reply #24 on: September 06, 2009, 11:30:04 AM »

regarding n2ey's reply....i commend you for actually researching before typing!  and you're pretty close!  old diesel truck alternators made by leece-neville are able to produce enough AC to power 4cx15000 tube amplifiers in vehicles.  in some cases multiple tubes.  in all cases multiple alternators and batteries.  heck, they have even adapted multiple lexadine ge=nerators from trains to provide voltage in their trucks!  they've been known to install a SECOND nitrous aided big block engine in the rear of a van to power the amp ONLY!  all these things are to be seen on the web.  parks across ny nj & PA have these things on display regularly. no shame no hiding, out in the open. and if someone complains of interference-they move!  they happen all over the US as well.  cbers have designed a thing called a 'motormaul'.  google it, or of that's too difficult, check here-http://www.cbradiomagazine.com/Articles/CB%20Motor%20Mauls%20Explained.htm.  maybe oversimplification of a very simple device that does not provide multitudes of power required to produce 7.5kw or more rf output, but enough output to make 16 or 32 2sc2879's work fairly well in a cbers world.  and no, these guys don't use wilson 2000 magnet mount antennas.  they put BEAMS on their parked trucks, at the very least they are using large pieces of metal that WILL handle far more then 1500 watts hams are limited to.  and no, they don't use rg58 or rg8 or 9086.  they use minimally rg218 which will handle almost 7.5kw at 27 mhz, for 25' which is probably more then they're using.  commercial hardline is also used.  at the very least they use bird commercial wattmeters, as well as top line commercial pieces.  do they have too much money to know what to do with it?  in most cases, apparently yes.  this is just MOBILE. there are more then a few regularly operating with more then 25kw.  there is a world famous rap singer that is known to use an amplifier made with a 4cx40 THOUSAND tube, in his studio.  WHY is it so hard to accept that it can be done?  ignorance may be bliss, but i KNOW of a ham using a homemade 3cx3000 tube amp on 6m.  does he exceed 1500 watts???  he CLAIMS not to, but come on, who buys a corvette to drive it at 55 mph??  i have heard many a discussion on 40, 20, 10 & 6m regarding the oversized tubes hams are building amps around.  i know of a particular one that i see parked from time to time and he has NEVER EVER interfered with me on 10m or any other band, so i'm not neccessarily inclined to care.
so, guys, come on, i personally don't care if they ain't bothering me, though there are many that DO care even if they're not being affected. i just have other things in life to worry about....i am sorry you have so much free time on your hands.  but pull your heads up from the sand & look around.  there probably is a bit of exaggeration here or there-i'd personally lie on the LOW side rather then the high side-but, research a bit & see what cbers are doing.  i will BET something can be LEGALLY applied to the ham bands here or there!
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ONAIR
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Posts: 1744




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« Reply #25 on: September 06, 2009, 08:22:22 PM »

I once saw a guy who had a huge amp in a van along with a gasoline generator!  Would have cost him a lot less to get a tech ticket and get on 10 meters legally.
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N5LRZ
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Posts: 0




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« Reply #26 on: September 06, 2009, 08:47:13 PM »

The "Jessie James Syndrome" has always been an all too attractive way of life for a lot of people--or so it would seem.
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N0ZNA
Member

Posts: 115




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« Reply #27 on: September 08, 2009, 06:32:51 PM »

I ran 11mtr ssb from 1969 till 1993.I got my lic then.With you background in antenna work and equipment,you should get you lic.I ran good equipment,and antennas.Your antenna is 99% of your equipment.Get the book,or just sit down twice a week on qrz.com and take the test question.Its not that hard.If you like 11mtr ssb,you will love 10ssb.And you dont have the am carriers,or roger beeps and echos.73s de JW
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W7ETA
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Posts: 2527




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« Reply #28 on: September 08, 2009, 11:45:28 PM »

I like to run a clean station also!  AND, I ensure my audio is good and clean, mic level adjust properly, NO processing!

PLUS, I do it on ham radio.

Bob
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AD4C2006
Member

Posts: 20




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« Reply #29 on: September 07, 2009, 10:07:49 AM »

Where you have been? Don't you know that very high power over 5KW and up to 20KW has become since many years ago the main fun and proud of all illegal cb'ers? C'mon,that's another old story,look,what could you tell me If I tell you that in the state of GA there was a MAJOR,yes Sir,a city MAJOR who gave permission to run a national "shootout" (that's how they call it) competition and after it was done they had a PARTY where the MAJOR was giving himself the trophy to the winner? That was in a website for years,its not anymore on the net,but this is going every year in the state of GA where the biggest guns on that band are,unfortunately FCC has no man power neither time to spend chasing all these violators but the day you be waiting at the red light for the green one and your stereo become crazy,your dome light will be flashing by itself and the car computer made your car to stop,spin your head around and I am sure you will find either an 18 wheeler or a big SUV with a couple of vertical with huge coils on them running more than 5K on 27Mhz.This is a national epidemy worse than the swine virus and thousand of CB'er are infected with it but the vaccine is not been produced yet and I don't think so it will.

Hector
AD4C
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