• 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.
  • Click here to find out how to win free radios from Retevis!

Cobra 135 23 ch B version Am modulation.

demco satelite

New Member
Sep 3, 2024
63
7
8
50
Any way to turn the modulation up in the 135 b version? Only thing I found involved removing a transistor but that 100% disables the modulation. I think that mod is for the earlier A version 135.
 

I'll start with disclaimers. I don't have one of these, so I can only work off of what I can find online. So I have no idea if the schematic I found on CBTricks is for the "A" or "B" version. Meaning I haven't tested this so don't blame me if your radio catches fire or something.

In the audio chain between the CB/PA switch and C174 (which feeds the base of Q32) is a fixed 10K resistor, R180, in the audio path when "CB" is selected. Changing that to a lower value may give you the increased audio you're looking for. Then again, it may just overdrive and sound like crap.

Schematic:
 

dxChat
Help Users
  • No one is chatting at the moment.
  • @ BJ radionut:
    EVAN/Crawdad :love: ...runna pile-up on 6m SSB(y) W4AXW in the air
    +1
  • @ Crawdad:
    One of the few times my tiny station gets heard on 6m!:D
  • @ Galanary:
    anyone out here familiar with the Icom IC-7300 mods
  • @ Crawdad:
    7300 very nice radio, what's to hack?
  • @ kopcicle:
    The mobile version of this site just pisses me off