View Full Version : Direct injecting Cobra 29 Tutorial

12-19-2017, 08:26 PM
You will need the following items:

1/4" (or whatever audio jack you prefer to use) audio jack
some wire for audio
a 25v 3.3 to 10uf capacitor (polarized or non)

Locate C37 on the board and remove the cap. You will connect the positive lead of your 25v cap to the leg of C37 closest to the center of the PCB board. On your negative lead of your cap, you will run your wire to the positive (center) leg of your audio jack. Mount your audio jack in the desired location. If you dont mount it in an area that grounds it, make sure you run another wire from its negative lead to a ground in the radio (a can or some other ground). I also reccomend cutting your audio wire from the mic jack in the front of the radio (pin 2) since it can cause some feedback when you have a mic hooked up to use as a keyer. You will have to use something to key the radio up. I would just use a stock mic or a foot pedal. Also, with this type of injection, you will hear your audio in the receive. Kind of like talkback without being keyed up. One last note, make sure you run this radio on its own power supply. If you run it with any kind of linear on the same power supply, you will more than likely get an awful squeal. I hope this helps someone out there.


02-25-2018, 07:14 PM
very good 73s

GA Buck
02-08-2021, 03:42 PM
Is the C37 cap the same in a Uniden PC76XL or does it have a different number? I have always been told 29s and 76s were clonesof each other.