Build CB Transiever

Thread Starter

RepublicanRF

Joined Jul 31, 2011
4
Hello all,

I have been interested for sometime in building my own CB radio transiever but I'd like to do so with solid state components. I've found multiple AM/FM/World Band SOC recievers & transievers but i cannot find one for the CB (USA) band. I'm assuming this, but being as you can by handheld, self contained CB radios (where all of the components are basically in the mike) surely someone is manufacturing these. Below are two links: the first is to a manufacturer of the AM/FM recievers that are examples of what I'd like to find a CB transiever in. The second link is just an example of a midland handheld CB radio --- I cannot imagine that the analog components are inside of here --- if you know different though please correct me.

So my main question is: Does anyone know of a manufacturer that makes CB radio system-on-chip transievers? All suggestions are welcomed.

Thanks in advance for all of your help.

SOC AM/FM recievers
http://www.silabs.com/applications/audio/Pages/AudioSystem.aspx

Midland 75-822 Handheld CB Radio
http://cgi.ebay.com/MIDLAND-75-822-...637862295?pt=US_CB_Radios&hash=item35b3167d97
 

Wendy

Joined Mar 24, 2008
23,415
Unless you have a Amature radio liscense you will not be allowed to build one legally at full power (5W).

I've built plenty when I was a teen in the 100mw power range, basically a simple crystal and transistor will get you on the air.

Given that they are commonly available and reasonably cheap, why not buy a legal unit?
 

Thread Starter

RepublicanRF

Joined Jul 31, 2011
4
Bill,

I have a couple of good store bought units. I just want to build one. The ones that you've built - with a crystal and transistor - could you tune them to more than one channel?
 

John P

Joined Oct 14, 2008
2,025
I think that on the build versus buy scale, this one is way down at the "buy" end. Spend a few bucks to get a commercial unit, then pay yourself back by working at minimum wage, and you'd still come out ahead in terms of the time it would take.
 

Wendy

Joined Mar 24, 2008
23,415
Changing channels on these units is simplicity itself, use a different crystal. The crystal determines frequency.
 

Papabravo

Joined Feb 24, 2006
21,159
Unless you have a Amature radio liscense you will not be allowed to build one legally at full power (5W).

I've built plenty when I was a teen in the 100mw power range, basically a simple crystal and transistor will get you on the air.

Given that they are commonly available and reasonably cheap, why not buy a legal unit?
Since the 11-meter CB band is not an amateur band, why would you need an amateur radio license to build a CB transceiver. BTW, IMHO even an Extra Class License does not require any great knowledge of circuit design or construction techniques. What a CROC if true.
 

Wendy

Joined Mar 24, 2008
23,415
Rules may have changed over time that I am not aware of, but there is (was?) HAM frequencies right next to the CB band. It was a source of linear amps, which was a major headache for those who were legit.

It is illegal to build and operate a CB (unless you keep the power very low) to the best of my knowledge. Except for certain critical frequencies the FCC does allow for very low power transmitters.

CB is considered to be the 11 meter band, and is not open to Hams far as I know. The 10 meter band (28Mhz and above) is open for Hams. The problem is that they are close enough that what works for one will work for the other.

Back in the mid 70's, where most of my experimentation was being done, their were radio control channels in the 27Mhz region. This has been changed and is now illegal, except for small toys.

To the OP, I don't think you are going to get much help here, unless you choose to get a technicians Ham license. It is against the terms of service to assist in illegal activities, which this is.

Commercial radios go through a rigorous set of tests to keep them legal and on the up and up. A home brewed setup can't keep up.

I think I can discuss theory OK though, CB channels support upper and lower sideband with suppressed carriers, which is very advanced AM theory.

Receivers are generally always legal, with certain exceptions.
 

Wendy

Joined Mar 24, 2008
23,415
It was one of the things I was thinking about. I've never been sure states have the right to ban them outright, but then who is going to fight it?

Another exception is services that expect pay for their broadcast, the measures/countermeasures game between satillite providers and crackers has never ceased to amuse.

Yet another exception is specialized government channels. Given our government has restraints on the basics as far as I know you are not allowed to repeat what you hear (or see) assuming you have cracked their security. I could be wrong about that one though.
 

Jimcsjr

Joined Jun 5, 2016
1
I think that on the build versus buy scale, this one is way down at the "buy" end. Spend a few bucks to get a commercial unit, then pay yourself back by working at minimum wage, and you'd still come out ahead in terms of the time it would take.
I'm sorry - this is more than ten years out of date - but my goodness, to say radio is only meant to be appreciated by using a commercially bought unit... I seriously think the OG replier forgot that they were posting on a RTFM kind of forum. I honestly think the only time you should ever nay-say - is never.
 

dendad

Joined Feb 20, 2016
4,451
Welcome to AAC @Jimcsjr .
Yes, this is an old thread.
But the comment that you are not allowed to make and operate your own radio transmitter other than a very low power is still valid.
It is not saying that radio is only to be appreciated by using a commercial unit at all. It is just that allowing anyone to make their own transmitter runs a very high risk of causing interference, and that may be to an essential service. That is why it is regulated. And it is well to be that way.
Years ago, (around 50) some high school chums of mine did just that. Unknown to them, they just happened to flatten the local fire brigade radios. A visit from the radio inspectors had them loose all their electronic gear. Fortunatly for them, that was all.
By all means, study to gain your ham radio license. Many of us have and it is a great hobby. Then you will gain the skills to make your own radios on the Ham bands. That is a lot better then just being stuck on the CB. Many frequencies and operating modes become available to you.
Ham radio operators have been in the forfront of many advances in the technology.
 

Papabravo

Joined Feb 24, 2006
21,159
The hottest new technology is a low power mode called FT8. The first trans-Atlantic calls on 432 MHz. were made just last week.
 

Papabravo

Joined Feb 24, 2006
21,159
Joe Taylor has a piece of software called WSJT that is a free downlod. I used it for Meteor Scatter QSO's on 6M, using FSK441 modulation. It now supports a number of low power digital modes including FT8.
 

nsaspook

Joined Aug 27, 2009
13,085
I completely lost interest in radio engineering after my stint as a radio professional in the military operating VLF to SHF, morse to high speed digital, land, sea, and air. 6 month long 12 on 12 off shifts locked in a crypto vault for years is like a professional baker and donuts. You can be extremely good at your work but yet, it's still work. Radio is a like a aroma that makes my bones hurt. I know the craft like the back of my hand but there is no interest in it.
 

DickCappels

Joined Aug 21, 2008
10,152
Unless you have a Amature radio liscense you will not be allowed to build one legally at full power (5W).

I've built plenty when I was a teen in the 100mw power range, basically a simple crystal and transistor will get you on the air.

Given that they are commonly available and reasonably cheap, why not buy a legal unit?
I think it was back in the 1970's that the FCC (United States Federal Communications Commission) threw up their hands and said "ok, its a free-for-all, You don't need licenses for the Citizens Band". Amature radio stations in the U.S. Still need to be operated by Licensed hams.

Alan Yates published a one transistor CB transceiver that might be a good way to start.
http://www.vk2zay.net/article/156
 

Toughtool

Joined Aug 11, 2008
63
The hottest new technology is a low power mode called FT8. The first trans-Atlantic calls on 432 MHz. were made just last week
Wow, That reminds me of my 7 mile transmission of standard TV (ATV) on this band from
Panama City to Lynn Haven FL. My best reception was Mexico City TV (commercial). The shortest distance (air line) between Panama-City [,FL ]and Mexico-City is 1,122.58 mi (1,806.61 km).
 
Top