Bells cb and screwdriver radio tech?

Yeah, that's definitely a spectrum analyzer. Maybe now he'll quit turning the modulation up too much...

 

But with my power ratio set at roughly 4.7:1 aren't I over modulated? It seems to sound good from what I can hear in the video.

 

Double post.

 

Typically, a 4-1 ratio is referred to as 100% modulation. When 100% mod is exceeded on the negative peaks, the carrier is cut off and overmod, distortion, bleed over occurs.
The positive peaks can exceed 100% mod, and not overmod, as long as the negative doesnt go beyond 100%. This is the importance of using an oscope when tuning the peak output, and not just a watt meter.
The thing is, its not as simple as just "peaking" the tx coils, and maxing the amc vr, or removing the limiter. Most radios require some modification, because the negative peaks will increase before the positive peaks do on most stock radios.

So, 4.7-1 is roughly 117% modulation. If the neg peaks are at 117%, yes it will be overmodulated. Will it sound good? Maybe, opinions may vary. If it bleeds over up and down the band, that will answer your question if it is overmoded or not.

Hope this helps.. and congrats on yur new radio!

 

Go to Bells CB website, click on tech library and read his little article about modulation limiters and he explains how he tunes up a radio.

 

I can live with that philosophy.

 

Just run the mic gain between 12:00 and 3: 00 and you should sound good.

 

That low huh? Ok that's where I'll start. Let me ask this though.. can I judge how I sound OTA based on what I hear through talk back? IE: will I be able to hear if I'm over modulating?

 

Depends. If the talkback is picked up after the mic preamp, no. Easiest way to tell is if the talkback works on SSB. If it does, your talkback picks up after the mic preamp. My Stryker is set up that way.

 

Ok. Based on the video it doesn't seem to be. Oh well.