Considering getting into CB

[Mudfoot]

Good deal!

 

[AudioShockwav]

I will not buy any new radios that do not have SSB, and the only radios that I own at this point in time that do AM only is a old cobra 29.
SSB is much more effective in that you do not have to waste energy in creating a carrier.
A typical 100 watt am station requires 50 watts of power to create the carrier, 25 watts to modulate the upper sideband and 25 watts to modulate the lower side band.
If you eliminate the carrier, and one sideband, a 25 watt SSB signal is as effective as a 100 watt am station signal.
That is a 4 to 1 advantage of SSB, and if you factor in the reduced bandwidth of the RX it is even more.
SSB is the way to go.

73
Jeff

 

[GnG8d]

I will not buy any new radios that do not have SSB, and the only radios that I own at this point in time that do AM only is a old cobra 29.
SSB is much more effective in that you do not have to waste energy in creating a carrier.
A typical 100 watt am station requires 50 watts of power to create the carrier, 25 watts to modulate the upper sideband and 25 watts to modulate the lower side band.
If you eliminate the carrier, and one sideband, a 25 watt SSB signal is as effective as a 100 watt am station signal.
That is a 4 to 1 advantage over SSB, and if you factor in the reduced bandwidth of the RX it is even more.
SSB is the way to go.

73
Jeff

I think you might want to check that math :/

But I understand people not wanting to go through the extra effort of an AM station, let's face it, SSB is just easier.

 

[w9cll]

Troll post

 

[Mudfoot]

Troll post

Say whaaaaaaaa?

 

[GnG8d]

Troll post

It's only a month old too, lol.

 

[GnG8d]

Actually an SSB radio has a clarifier because the clarifier control is actually a tunable carrier oscillator called a BFO (beat frequency oscillator) that has to reinject the missing carrier into the signal to replace the missing carrier that is filtered out in SSB mode.Without that reinjected carrier you would not be able to demodulate the signal. The fact that SSB is narrower does however mean you can fit a bit more stations into the same space, however that is not the reason that SSB radios have a clarifier.

Yep, I misspoke. The clarifier is not because of SSB, but SSB is more efficient because of the clarifier.

 

[AudioShockwav]

I think you might want to check that math :/

I should have wrote of ssb, not over ssb,but what is wrong with the math?
AM transmissions include the carrier and both sidebands, all combined. It takes power to generate these signals, with most going to produce the carrier which contains no useful information
Since the audio information is contained in the upper and lower sidebands, it makes more sense from an efficiency standpoint, to filter out one of the sidebands and devote the available power into producing one sideband,and removing( or supressing) the carrier.
The amount of power devoted into producing one sideband is much more efficiently used than the same power producing an AM signal, that is two sidebands, plus the carrier and this translates to a much greater range with SSB over AM using the same amount of power.
The sum of the power in the two sidebands can't exceed half that of the carrier.
25 watts of single sideband is equal to 100 watts of 100% modulated am signal.


73
Jeff

 

[GnG8d]

100 watts pep is the same AM or SSB, it's no real measure of power, it's just the peak modulated envelope. Now the average power will be 37.5 watts AM while SSB will be 6.25 watts on each side band. So if you wanted to put that into a ratio, it'd be more like 6:1 and then take the narrow banded nature of SSB into account and it's far more efficient than that.

 

[AudioShockwav]

ok, if you want to look at it in a different way, you should have about (+/-) 9dB of overall improvement using SSB as compared to AM.
Approx 6 dB at the transmitter due to the elimination of the redundant carrier and approx 3dB at the receiver as compared to AM.
One sidebands worth of power usage and all of the power used to create the carrier is not needed on SSB


73
Jeff

 

[GnG8d]

Okay, I'll admit I've never looked at it from the standpoint of decibels. But on the surface 100 watts pep is still 100 watts pep.

 

[DuckSoupe]

I started out with a President hr2510 CB radio. I have had it for years. A first time purchase would be a sideband radio for sure.You find a more serious radio enthusiast on it. There are other things done to sideband I will not discuss; but definitely go sideband.