Loss of some channels on TX.

[QRZ-934]

Attached the logic probe to pin11 of the pll.
Radio off and cold.
Turned it on and set channel to 25, no lock.
Ch24 was locked and after a few seconds started to lose the lock as the signal was pulsing.
Went down to 24, channel was locked, waited a short while, started to lose lock.
Blew cold air on the board in the vicinity of TP1 and the vco, started to reverse the loss of lock eventually just by blowing cool air on it the channel was totally locked again.

Something is obviously warming up or losing stability in that area but ive yet to identify it.
I also decided to try and lower the volts on TP1 by running the radio at reduced volts, (10) which it did, although the voltage was only marginally lower and it still lost lock.

[Alucard]

Time to get out the can of freeze spray..

[QRZ-934]

Time to get out the can of freeze spray..

Ah well, the blowing on the circuit board to effect a temporary halt to the loss of channel lock is now clearer.
Turns out theres temperature controlled crystal oscillator in a metal can right next to TP1 and the vco .
Me blowing on it has some of the air entering the adjustment hole in the top of the can and well, you know the rest.

Still no wiser as to why the volts are so high on TP1 as the only resistor in line with it is a 560ohm smd thats in spec and isnt getting warm, the other resistor to the vco block is a 2.2kohm also a smd and also in spec.
I might have to desolder the 560 ohm one to cut the 8 volts entering the vco and feed it with an external 3.5-4.5 volts and see if that cures the lock loss issue.
First up order up some smd's........