Cobra 140gtl with two dead channels?

[Radio Face]

Just out in the shed today playing around with my Cobra 140gtl that is hooked up to my base antenna.
Anyway, noticed it will not give a static sound on channel 39 or 40. Also no transmit or receive. When I key it up on 39 the transmit light flickers and it makes a quite sputtering sound but on 40 nothing at all through my talk back radio. When I switch to another radio and try and transmit back to it, the signal meter moves but no sound. Any ideas? Thanks Radio Face.

 

[Robb]

Possibly the VCO voltage is out of adjustment; most likely.
Possible dirty contacts in the ch selector switch.

 

[999]

Possibly the VCO voltage is out of adjustment; most likely.

I'm going with this. And it very likely is a symptom of other underlying issues. My best guess...related to electrolytic capacitors and possibly conductive glue.

 

[Radio Face]

Update...I did the fast channel change knob rotation and now I have 39 back. Still no 40

 

[El Kabong]

Buy some spray contact cleaner, like DeoxIT D5, off eBay and squirt some in the selector guts. Works like a dream.

 

[dss56]

I would tweak the vco first check the voltage but sounds like the vco drifted a bit and maybe an adjustment will cure the problem.

Does the radio have extra channels?

 

[Radio Face]

No extra channels

I would tweak the vco first check the voltage but sounds like the vco drifted a bit and maybe an adjustment will cure the problem.

Does the radio have extra channels?