TX BANDWIDTH

[Sonar]

What's the average TX bandwidth of a cb radio (unmolested)?
Do newer CB's operate wider TX bandwidth out of the Box than an older vintage 40 channel rig (AM/SSB)?
Is there a limit the FCC applies for manufacturers of cb radio's When it comes to bandwidth?
Do tube plate modulated rigs operate wider than a transistorized rig? Did search the www but found nothing so I thought I'd ask.here. 73

 

[tecnicoloco]

What's the average TX bandwidth of a cb radio (unmolested)?
Do newer CB's operate wider TX bandwidth out of the Box than an older vintage 40 channel rig (AM/SSB)?
Is there a limit the FCC applies for manufacturers of cb radio's When it comes to bandwidth?
Do tube plate modulated rigs operate wider than a transistorized rig? Did search the www but found nothing so I thought I'd ask.here. 73

 

[Captain Kilowatt]

That just shows frequency response but has no reference as to how that frequency response rolls off. Frequency response is not the same as bandwidth. In fact bandwidth is typically twice the highest modulating frequency thus if the TX is faithfully reproducing 3000 Hz the bandwidth is 6000 KHz because of the mirrored sidebands however you have to consider how steep the TX IF filters roll off. There should be specs similar to the selectivity which rates a level of roll off in dB for a given frequency removed from the centre carrier frequency ie. TX bandwidth of 5 KHz at -6dB. Very few radios seem to contain this info in their specs. You can determine it experimentally with the right gear however. Generally we consider a typical CBto have a TX bandwidth of 6 KHz in AM mode and 3 KHz in SSB mode however that is a generalization and will vary from model to model.

 

[M0GVZ]

Don't your FCC regulations specify what it has to be? They do over here in the EU. FM deviation is 2kHz, SSB 3kHz.

 

[rabbiporkchop]

I'd like to see what a stock rig looks like on a.m. at 5000 Hertz

 

[Road Squawker]

Don't your FCC regulations specify what it has to be? They do over here in the EU. FM deviation is 2kHz, SSB 3kHz.

Yes, the FCC regulations here do specify the max band width.

FM deviation (or modulation index) does not apply here for CB.