Monday, August 15, 2005

Anyone monitor 27.185 MHz lately?

((This is a little post to a message board making fun of people who use illegal CB radio equipment, yes, this is what happens when you have a scanner and to much time!))

I don’t know what it is about that frequency; there sure are a lot of over modulated 20 kHz wide AM signals centered on 27.185. Wow, a signal wider than the entire audio spectrum. Must be someone transmitting on gear they know nothing about, but have tried to soup up to do something that they shouldn’t. Oh, and some seem to think, the louder they shout into the microphone, the better their signal will be. News, it’s an unintelligible mess, and I’m not talking about the horrendous English.

For those of you that wish to monitor, first, cover your children’s ears. Second, a quality ground plane antenna can be built out of aluminum tubing with a vertical element measuring 103.292 inches and four radials of 103.292 inches. This antenna would be good for transmitting as well, but we aren’t talking about that right now, if we were, we’d want that vertical element to be 258.23 inches long in order to achieve an RF radiation pattern toward more toward the horizon instead of up into the sky where it may reflect off of the ionosphere and cause interference to other users of the frequency more than 155.3 miles away. Just to be on the legal side, you would want that antenna to be mounted 19 inches below the highest point of the structure it is mounted on, with the highest point of the antenna not to exceed 60 feet above ground level.

The equipment used on this frequency seems to fall in to two distinct classes, legal and illegal. Any general coverage all mode HF receiver is legal to use when receiving transmissions made on 27.185 MHz, as are some scanners than can receive frequencies in this band. Legal transceivers for the frequency 27.185 must be approved by the FCC and are not allowed to be modified. If they must be repaired for some reason, it must be performed by a certified technician. These radios tend to have much better signals than others. There seem to be many illegal transceivers in use on 27.185 MHz, what I find disturbing is that some of them use distinguished names like President Lincoln, General Grant, and even General Washington while others have more mundane names like Galaxy Saturn Turbo, Magnum S-3, or Connex 3300HP. Some transmissions appear to be so distorted that only very low quality, but high power RF amplifier could be to blame, that wouldn’t quite be legal either.

What I really want to know, is, what is up with all the echoes on 27.185 MHz? Are these people trying to hold a two way conversation, or are they just making RF for the fun of it?

You know, I was listening to 29.150 MHz the other day, a rather polite gentleman was discussing an old Collins transmitter from the 50’s that he rebuilt, the one he was using to hold the conversation at that moment. I was receiving him 5-2 on my scanner, the signal wasn’t strong, but it was coming from about 200 miles away. What made it different from what I often hear on 27.185 MHz is I could actually understand what was being said. I wonder why there is such a difference, I mean, its all radio, isn’t it?

I guess, all users of 27.185 MHz aren’t bad, in fact, I’d say the majority who use the frequency do so properly, but the few bad apples in the group, tend to bring down the group as a whole. I guess that is all I have to say about that.


Anonymous said...


If you haven't figured it out yet, 27.185 is "Channel 19" on the CB band, where truckers communicate with each other. Three years for this post, eh!

Anonymous said...

thats funny like the other guy said
its channel 19.we have 10 meter radios and linears tuned run at cb
frequencies. 27.185 is a dirty channel.

Anonymous said...

quite clearly this scanner user was not very experienced, either that or he was not following his hobby properly. if he did he would know what he was listening to on 27.185 AM, channel 19 CB which is on the mid block comprising of 40 channels between 26.965-27.405. this particular band is used internationally by CB operators all over the world. I agree there are some idiots on CB radio, but there are also idiots on Amateur radio bands too, partularly on 2 meter VHF. so all in all its just like everything else in life. there are always the minority who seem to abuse things. of course you can now use any mode of transmission you want in Britain, ever since AM and SSB was legalised last year. providing of course you stay within the confines of the EU band 26.965-27.405 and use type approved equipment. basically that means no old sidebanders, no modern export radios and no converted amateur radio equipment. two other points the scanner user should be aware of are: 1) prior to june 2014 it would have been illegal for him to listen to AM broadcasts on channel 19, because the laws only allow the general public to listen to broadcast radio, licensed amateur radio operators and license free radio communications. anything else is not permitted, including monitoring unauthorised radio operators on illegal CB frequencies, even listening to the civil aviation band on VHF is illegal according to the wireless telegraphy act, although its tolerated and ive never known of anyone who's been prosecuted for it. its even illegal to listen to your local dustman too! and if you dont believe me check it with Ofcom. many people mistakingly believe that its perfectly legal to listen providing you dont act on the information you have heard, this was also thought to be the case while monitoring the Police prior to when they switched to digital tetra radio. this is just a myth and IS SIMPLY NOT TRUE AND HAS NEVER BEEN TRUE, and if you get caught with sensitive frequencies stored in your scanner the authorities will prosecute you, of that you can be sure. the public are only allowed to listen to the services I have already mentioned and nothing more. 2) the scanner user should also be aware that many radio amateurs started life on CB radio, and many of them also used illegal frequencies like 27.555mhz in order to DX via USB, or even 27.185 AM for local chat. today channel 19 mid band is relatively quiet, although you do sometimes hear irish truck drivers on the motorway passing through on AM who typically use illegal foreign rigs like sidebanders and AM/FM rigs. all the points I have mentioned here are facts, and having been involved in radio communications for over 30 years myself, I know exactly what iam talking about.

Anonymous said...

PS: The information provided above only applies to the United Kingdom.

Anonymous said...

The reason youre hearing a "polite" man on 29.15 is because that is the "well educated" 10 meter ham band. On the other hand 27.185 is the cb radio world. So as far as it being "all radio " its actually different and not always all radio