2
$\begingroup$

I have a CB radio and I occasionally mess with a cheap SDR Dongle I have. I can pick up CB transmissions no problem but would like to be able to broadcast from my SDR. Is there any way to do this? I believe that it is a RTL-SDR I have never really been able to figure it out.

If the radio is not compatible do you have any recommendations of one that is?

$\endgroup$
  • 1
    $\begingroup$ What SDR is it? Many of them are receive-only, but we can't tell without the model number and/or chipset information. $\endgroup$ – user2943160 Jun 24 '16 at 23:06
  • $\begingroup$ Add that info directly by editing your question, not as comment! $\endgroup$ – Marcus Müller Jun 24 '16 at 23:19
7
$\begingroup$

An RTL Dongle is Receive-Only. You can't transmit with it.

$\endgroup$
5
$\begingroup$

CB is licensed by rule (like FRS), and CB transmitters must be certified by the FCC (also like FRS). If the SDR you're using doesn't have an identifying label on it, you're probably not allowed to transmit on CB frequencies (of course, monitoring them is fine).

So, aside from the technical question of whether your SDR will transmit in that band, you need to make sure it's FCC-certified. I did a quick search in the FCC OET database, which is where records of equipment authorization are found. CB is regulated under Part 95D, and the search page even has a convenient "software defined radios" checkbox. There were no results with those two criteria. Unless I'm running the search wrong (if someone else gets a different result, please say so), that means there are currently no SDRs certified for use on CB channels.

Monitor away, but know that transmitting with uncertified equipment is illegal, and the penalties can be quite severe. If you don't have one already, maybe you should consider getting an amateur license! You'll get a lot more flexibility in where you can transmit and the equipment you use.

$\endgroup$
  • $\begingroup$ Thank you so much for your help. I've been thinking about it but just haven't had the time yet. $\endgroup$ – jacksip Jun 25 '16 at 12:12
  • $\begingroup$ You probably don't need to set aside a big block of time to get your ham license. Get a license book and look through it (the ARRL manuals are thorough, the Gordon West books are designed to teach you just what you need to pass the exam), and take an online practice test at least daily. The practice test gives instant feedback to tell you what the right answer is if you make a mistake. Soon the answers stick in your head. Before you know it, you'll be ready for the exam. $\endgroup$ – rclocher3 Jun 27 '16 at 16:23
  • $\begingroup$ FCC certification on CB bands only applies to the U.S. and other territories that recognize FCC regulations. But other regions may have laws that are even more strict. $\endgroup$ – hotpaw2 Oct 2 '16 at 21:06
  • 1
    $\begingroup$ @rclocher3 I went from "I should get a license" to Extra in about 8-10 weeks of very part-time study (15-20 minutes most days, no session longer than an hour) with an online study aid. Took all three tests the same sitting. Not free, but well worth the cost of a cheap Chinese HT that I did spend. $\endgroup$ – Zeiss Ikon Aug 16 at 13:32
  • $\begingroup$ @ZeissIkon nice work! $\endgroup$ – rclocher3 Aug 16 at 19:27
0
$\begingroup$

You can transmit arbitrary data with a hackrf one or a hackrf blue. Both will work with gnuradio. The frequency range is very wide, see http://www.rtl-sdr.com/hackrf-initial-review . The output signal will need amplification.

$\endgroup$
  • 1
    $\begingroup$ This would not be legal on the CB bands, as noted by Rafael KG7YWU in their answer, because the device is not certified for Part 95 operation. $\endgroup$ – user2943160 Jul 9 '16 at 0:22
  • $\begingroup$ Right, I am aware of that. But it is possible to stay within legal output power using only a modest amplifier, as the hackrfs are well known for weak tx power. It is a well documented platform, it's scriptable (python at least has libraries for talking to it) and it is compatible with gnuradio. If OP doesn't exceed legal wattage and is careful not to exceed the frequency he is allowed to use... Why not lwt him have his CB instead of scaring him? $\endgroup$ – user400344 Jul 9 '16 at 8:26
  • $\begingroup$ The answer was not limited to only territories covered by U.S. law or FCC regulations. $\endgroup$ – hotpaw2 Oct 2 '16 at 21:04

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.