• You can now help support WorldwideDX when you shop on Amazon at no additional cost to you! Simply follow this Shop on Amazon link first and a portion of any purchase is sent to WorldwideDX to help with site costs.

questionable mod?

Yeah, I hear you about the lightening horror story. :confused: What a pain.

The resistor/jumper found feeding signal from driver to final has been a prime candidate for circuit tweaking, if they have a resistor present from the factory, downsize it by half (100 Ohm to 50 Ohm)
to increase power.

Or add resistance to decrease the power/D.K. (A.K.A. JP36 mod cobra 29)
If you want it to over-modulate you can add a capacitor across the resistor, just stay 220uF or under, else it tends to get really nasty. Can't say that I recommend a mod to over-modulate, but some people want the little radio to "swang" at any cost. :eek:
I was looking at the schematics on some of these old cbs I have and on a few of them the driver is directly coupled to the final. A few of the others there was a resistor. On all of them it was from the collector of the driver to the base of the final. One thing I noticed that puzzled me was the complete lack of a biasing resistor on the base of the final on some of these cbs
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ heartbreaker3473:
    Hello gentlemen and Ladies. I have the dreaded RCI-2990 receive issue where my radio gets distorted when people get close to my location. I found the C90 Capacitor, but I can not for the life of me find the C89 capacitor. Can or does anyone have a picture of the exact location of C89 ? Thank you in advance, Wes
  • @ AudioShockwav:
    Wes, it's better if you start a thread on the main forum, more people are going to see your question.
  • @ heartbreaker3473:
    Okay, sorry, will put in a forum
  • @ heartbreaker3473:
    I put it in the general disscution help area and started a new thread. Thank you for letting me know.