CB FM mode TX/RX add-on PCB kit need some help

[grimace]

CB FM mode TX/RX add-on PCB kit Has anyone bought 1 of these kits off ebay before? I bought some of these a while back and I've never got around to install one. They did come with some instructions for different radios but none for a cobra 29LTD or GTL. The problem I am having is trying to find out where +TX and +RX go in the radio on some the instructions the +RX is not used so can the +TX Be put on constant 13.8V and not need the +RX? On some of the instructions the +TX is hooked to 8 volts on transmit and the +RX is hooked to a 8 volt on receiver.

 

[nomadradio]

In that radio I would attach the +Rx to pin 3 of the mike socket. This is as close to a switched receive-only voltage as you'll get in this radio. The +Tx comes from the collector of TR21, the center leg.

Haven't seen a FM add-on kit for a CB since the 90s. CBC International sold them at the time. One 'club' had it installed on their members' radios and figured out it was only good for local use, and only when the skip died down. Haven't yet laid eyes on the kits they sell these days.

73

 

[grimace]

I found the schematic it does look like both of them have to be hooked up and on some of his instructions it don't have both of them hooked up It was making it kind of confusing Thank you nomadradio for the help

 

[techradioman]

What's the Ebay link for this FM kit ? I would like to check it out.

 

[grimace]

What's the Ebay link for this FM kit ? I would like to check it out.

It says he will not be back until June 25 So if you did a search that might be the reason why you couldn't find it. I think when he comes back from vacation he'll probably put it back up on ebay again.​

 

[grimace]

Here's a YouTube video of it