I hear all these stories about people getting fined for amping up their signal on CB's, ham, whatever... i was just curious how they could get caught.. does the signal work like a GPS for people trying to find others? Or is this primarily for stationary locations... i couldn't see how a mobile unit could ever get caught... i was just curious how that would work. Thanks!

 

Unless it was the diesel police harassing an occasional truck driver for a linear during an inspection at a chicken house or during traffic stop I can't recall a geeked up mobile unit ever being tracked down and cited. Usually its a BIG base station known to have been causing interference problems with someones TV or other piece of electronics that gets their attention before they go looking. When I say BIG some of these guys run 1000's of watts.

A CB is like anything else giving off a radio signal....it doesn't take much to track its origin and that can be done with something as simple as the signal meter on the front of a standard CB if one was so inclined.

 

Before the FCC field offices will get involved, there has to be some other complaint filed against the person first. Something like interference with another radio service or net, continued profanity, etc. Then, if they have the manpower, the FCC will send out one of their mobile vans from the closest field office. These vans are equipped with direction finding gear and antennas. They'll first triangulate a rough position to pinpoint the city/area. Then they'll cruise street to street to find the vehicle or house. The number of these vans is limited, I think I remember reading that there's something like 11 of them in the country. Their number one priority is finding operators who interfere with licensed radio services, especially emergency services, and federal frequency allocations. CB is way low on their priority list, though they have on occasion gone after individuals there.

The FCC maintains a website where you can see enforcement actions taken against the Amateur radio services here:
http://www.fcc.gov/eb/AmateurActions/Welcome.html


Where you are more likely to run into problems is if you are running a CB that is non-type accepted by the FCC. For CB (and FRS/GMRS), the radios have to be certified by the FCC on a per model basis. Some brands like Galaxy also sell radios for export that do not meet US FCC type acceptance, and sometimes they end up getting sold in the US. They generally put out more power than what is allowed in the US for CB, or they are 10 meter radios that can be easily modified to use on CB. There are some state police savy enough to know this and if stopped, they might look at the radio if they were trying to get you for something. Regarding the state police, this is what I've read, and been told, but have zero first hand experience with it happening to me. With these types of radios, the FCC uses their manpower to go after the companies selling the products versus the individuals using them.

http://www.eham.net/articles/8189

Within the last year, there were two instances of mobile abusers being tracked down and caught. One had a police handheld and was making bogus officer down calls. Turned out to be a Sheriff's auxilliary guy too. Another was a guy with a marine VHF in his car making bogus distress calls to the coastguard. The Coast Guard is pretty good at "getting a fix" since they are equipped to locate vessels in distress by triangulating position from multiple receiver sites. I highly doubt though they have the bandwidth and resources to go after a guy in his jeep running 25 watts illegally unless that person is also interfering with another licensed service.

Pretty much any emitted radio signal can be traced back to the point of origin, even one that is moving.

 

1000's of watts? That sounds a bit ridiculous, unless you have a huge antenna mass behind your house.

 

There are "competitions" where a group of folks get together and key their mikes at the same time while another person goes a distance away... whoever is heard is the winner. These are mobile units that drive to a pre-determined location.

Some have upwards of 10K watts going through multiple antennas, usually suburbans or vans, most running 2-4 leese-neville 250+ amp alternators, they're quite the setup, running the 12V up to 110V then through pole pigs(transformers) to get the 10+K watts.

LN alternators are the ones used on big rigs.

edit: Sorry I meant 10K+ Volts which is used by the amps to get the thousands of watts... wife's cousin had an X hubby who built his own ham radios.... used pole pigs to easily get 2K watts... his method of testing was to put dummy load onto transmitter, then tie mike open for about 12 hours

 

Yes, HAM ops used to build their own radios all the time....not as much anymore, but there are still a few. Mostly the things we build now are antennas and amps. We as HAMS, depending on the band, are legally allowed to TX up to 1500w. The amp I use in the shack, depending on the band, can get upwards of 1300w.

 

While that would certainly work on FM, where only one transmitter can capture the receiver and lock on, in AM (like CB), you'll hear all of the transmitters together. That is why air band radio is AM still to this day. If there is an aircraft in distress making a call, you'll still hear him even if someone else is transmitting on that frequency too.

 

What you'll hear is a squeal--or several squeals when several transmitters are involved. The squeal is at the difference frequency between the two (or multiple) carrier frequencies of the transmitters. While we may think of all of the radios as being on the same frequency, they're actually not likely to be. That difference, caused by inaccuracies in hardware performance and environmental differences in the gear, is usually only a few hundred Hertz off. Beat those frequencies together and you get the very audible squeal. Beat multiple frequencies together and you get multiple squeals. That squeal is what CBer's colloquially call "being stepped on." If you have one particularly strong station, his signal can override the others and come through loud, though perhaps with some subdued squealing in the background. Of course, that depends on a variety of factors, including power output, distance from receiver and propagation affects.

Back to OP's question: In my younger days, when an active ham (WB6MPD), a friend of mine decided to run an all-music radio station. This was the late 60s. He put his 160-meter transmitter at the very top end of the commercial AM band, and began transmitting from his personal music collection. It was great, for those of us who knew where to tune. Well, until the FCC paid a visit to his home after about two weeks. It seems that he was transmitting almost on top of the LORAN station located at the Silver Strand in San Diego (you've seen it if you've driven out on the Strand--it looks like a big elephant cage). My friend learned exactly what bearing he lived from that station. It was fun while it lasted.

 

Loran is at 100KHZ and the top of the AM band was 1620KHZ. Hardly on top unless he had a really dirty transmitter. STuff like this really shines a negative light on HAM radio, even to condone it or associate with someone who does it.

 

You're absolutely right about condoning it. But I was all of 16. I would discourage anyone from violating the FCC laws today (and have written to that affect in various threads here on JK-Forum). I should have probably said so again in my first post; thanks for bringing it up.

You are, however, wrong about the operating freq's. The transmission frequencies of 1750 kHz, 1850 kHz, 1900 kHz and 1950 kHz were used for LORAN-A (I did say in the first post that it was in the 60s--100-KHz LORAN-D was a pipe dream back then).