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Radio Make and Model: Ham international Jumbo
PCB Number: PBTM059cox
PLL Number: Pll02A
Test gear available: Scope, Freq. Counter, DVM, RF sig. Gen, AF gen. Wattmeter
Symptoms: All channels off by 6kHz

What is working: All working

What has been tried: Trying to do full alignment

Did it suddenly happen ?: No
Anything else that may be of help?:

Bought radio with unknown past although looks untoched apart from PSU which has had transistor replaced.
Noted all channel freqs are 6kHz below what they should be so got hold of service manual for Mk1 and started working throught it.
Psu was giving low output 12.2V now corrected to 13.8V
PLL REF FREQ OF 10.240 spot on.
Next item for checking is the offset frequencies and this where I need some assistance.
The manual states with frequency counter on PTOS006 PCB TP4 :-
adjust CT2 on lo to 20.105MHz
CT3 on mid to 20.330MHz
CT4 on hi to 20.555MHz
My problem is none of these trimmers are making any change.
Any ideas? I have checked that the band switch gives 0V on posts 1,2 & 3 at lo, mid & high respectively.

I can get the last part of the offset alignment to work ie. max amplitude on TP4 using a scope & and adjusting T1 with a freq set of 10.695MHz.
Also I find that CT5 will not bring LSB offset inline to 20.1035Mhz, but CT4 will adjust to give 10.692MHz on TP5

I had a similar problem with a Cobra 148

It had been modified to cover extra frequencies & one of the diodes had gone - no matter how far I adjusted the pots I couldn't reach the offset frequency

You didn't say if your Jumbo is modified but maybe worth checking out before starting to look at the binary adders etc?

I'm sure someone more knowledgable than me will be able to shed more light on it for you.

Steve,
It's a Jumbo (Cybernet) not a Uniden, they don't have any binary adders they switch to a different crystal for each band.

Of course they do Dave

Anway he's found the fault now, it was a bad connection on the mode switch, I think!.

Yes to clarify, the problem was a dry joint on one of the wires to the Tune pot.