Cobra 29 channel 19 is sometimes on 18!

[Mudflap1]

I am working on my buddy's 29, he's having problems with it drifting channels. Sometimes he will lose people on 19 flip to 18 and there they are, it happens on rx and tx. I have checked the voltages on the 2816 PLL and they are good. Pin 10 is perfect at 5.12 mhz, pins 12 and 13 are dead on at 10.24. Pin 22 is the one that has me stymied. It reads about 3.89 mhz on ch. 1 RX, and 26.965 TX. I know that it should be .91 and 1.365. BTW, IC2 is good as far as voltages. Also, someone put an echo in and used the delta tune for the controls. D17 does have an 8.2K in series with the diode. Any ideas on where to look? I am no expert, still learning here!

[443 Arizona]

my guess is the clusterbunch of voltage piling up from the echo hack is backfeeding/spuriously bleeding into and overdriving the pin 22 immediate circuitry.
replace IC,,,,?
ok get a professional opinion because i only have a screwdriver and hammer

[pabxone]

Does this version of the Cobra 29 have a Ch 9 / Ch 19 switch by any chance ?

IE a Cobra 29 NW LTD or 29 WX ST NW ?

Pin 22 on a uPD2816 is "Freq In" and that should be changing with the selected channel

[sonoma]

Guy's this post is over 1 year old. posted Jan 2016. rather dought any one is still messing with this one.

[pabxone]

Guy's this post is over 1 year old. posted Jan 2016. rather dought any one is still messing with this one.

Well spotted - Don't I feel and/or look like a goose now !