Uniden Pro 520xl modulation increase

[Hardhead]

If you have searched the different CB repair sites (CB tricks, Deform) you have probably found as I did that the info on this radio was not current. The new radios have surface mount tchnology. They use a different schematic nomenclature.
The schematic has not been released by Uniden, or so they say. I called and talked to a rep there. If anyone has the print I would be interested in it.

The diode to effect to increase the modulation is D203. By adding resistance in series with this diode you can increase modulation without causing distortion. By tuning the final circuit I was able to get 10 watts swinging 20 watts with over 100% modulation. I tuned back to 5 watts because to output sounded better.

Just for your info. :idea:

 

[Hardhead]

Question

Does anyone know where to put the resistor to give the 520xl a talkback? I'm going to put it on my bike and I need talkback in my ear to hear what I'm saying.

 

[Moleculo]

Hardhead, if you give me a day or two, I'll pull mine out of the car and try to figure it out for you.

BTW, did you try the standard resistor from PA to ext speaker trick?

 

[Hardhead]

BTW, did you try the standard resistor from PA to ext speaker trick?

Yes, And it didn't work.
Thanks.

 

[Hardhead]

Hardhead, if you give me a day or two, I'll pull mine out of the car and try to figure it out for you.

BTW, did you try the standard resistor from PA to ext speaker trick?

I'm curious if you had a chance to look at your talkback setup.