peepsman

Ok, so I'm not that smart. I understand CB. I started in CB when you needed a vibrator type of converter in you car to run a base station in it to convert from 12 volt to 110 volt, but can someone explain SSB to me?

AK4Dave

Single side band.....? What is it that you want to know? Other than it's way more efficient than AM as far as communications go......read this:

http://en.wikipedia.org/wiki/Single-sideband_modulation

Mark Doiron

The short version: When you transmit over a radio in AM (Amplitude Modulation), you send a carrier frequency, plus two sidebands. You may remember from high school physics that if you took two tuning forks close in frequency and struck them both at the same time that you'd hear two high pitched tones, plus a slow warbling tone. That latter tone was at the "beat frequency." Basically take the frequency of the two tuning forks (for example 655 and 660 Hertz), add and subtract them (5 Hertz and 1315 Hertz) and those are your beat frequencies. In that high school class, most people can easily pick out the 5 Hertz example, even though the higher frequency may not be noticed with the other frequencies that are present.

Anyway, back to A.M. One of the tuning forks is represented by the carrier frequency. The other frequency is constantly changing: It's the frequency of your voice. Mix the carrier and your voice together, and you get the resulting transmission of a carrier, a lower sideband (your voice frequency subtracted from the carrier) and an upper sideband (your voice frequency added to the carrier).

Now, if the intelligence. what you're saying that is, is completely carried in one of the sidebands, why even bother transmitting the carrier frequency and the other sideband? Why not just put all of the power into that one sideband, and improve radio performance? Of course, at the distant end you'll need to reinsert that carrier in order to extract the intelligence, but that's easily handled. So, that's what is done: SSB is the transmission of just one sideband. And, yes, two parties can have two different conversations going on while sharing one frequency--one on the upper sideband, and one on the lower sideband. So you've also reduced bandwidth congestion. BTW: If you listen to a SSB signal without reinserting that carrier, it sounds somewhat like Donal Duck talking.

Final thought: I've never seen a Jeeper use an SSB rig.

AK4Dave

And that's too bad too. Because like I've said it is a far more efficient way of communications......ie,

Far less congestion on the channel of choice, (as an unspoken CB rule channels 30-40 are usually used for SSB coms)

More audio (louder) because most CBs that have upper and lower sideband, even though it's a 4 watt CB, (AM) the SSB audio transmitted is equivalent to about 12 watts. This extra "power" so to speak, added with less congestion, means better distant communications.

Plus, when using SSB, it's almost like having a private conversation. Because you can't be understood by others listening in using only AM.

SSB is less prone to signal fading as is AM.....like you hear on the broadcast radio stations at night where an AM station will be bangin' in one minute and gone the next. Altho SSB will fade in and out, it's just not quite as bad as AM.

Because of these examples, almost all phone (voice) coms on the HAM bands are done in either USB or LSB.

If you are looking at buying a new CB, altho a bit more expensive, I suggest buying one that has both SSB and AM. And encourage the others in your wheelin' group to do the same. You'll be glad you did.

Oh and thanks Mark for the explanation....good job...!!!

peepsman

Thanks guys for the info. All of it makes great sense. What doesn't is since SSB radios are really not any more expensive than a good CB, why don't we use those?

donnie

IV got an old Cobra 148 sitting in the garage that I used to use years ago.
IMHO, SSB does work great but would be more of a PIA when on the road than it would be worth.
IF I remember correctly, it needed fine tuning of the audio once in a while which would be a pain when wheeling.
But thats my opinion.

AK4Dave

Like you, probably most just don't understand, and realize the potential......

AK4Dave

Normally, all a person needs to do is use the RIT (clarifier) on the radio to tune the other person in so his voice sounds normal, one time and that's it.....don't have to touch the radio again. What "can" happen is if you are having a "round table" and one person has a radio that is off frequency a little, or moves off frequency as he talks. Then all that means is that one person wouldn't sound quite like his natural voice. Not that you couldn't understand him, just that he would sound a little different. But the truth is, after you learn how to use SSB, it becomes as easy as communicating on AM. If it wasn't all the HAM ops wouldn't be using it.

JKGuy

Over seas and down south they also use FM (Frequency Modulation). Much cleaner sound and easier to understand. Wish they'd allow it in the U.S.

peepsman

Ok, so I'm seeing the whys and whatfors, but correct me if I'm wrong, (which I'm sure someone will do), you still have the "normal" 1-40 CB channels, correct? Then, you have "side channels" along each of the 40 CB channels. So the radio can be used strictly as a "CB", but you just have a "side" choice to communicate with someone on the "like" side channel?