[TenTec] Corsair frequency display issue

[Dr. Gerald N. Johnson]

On Thu, 2010-01-21 at 17:52 -0800, g p wrote:
> Somehow I misunderstood and thought the jumper was inside the radio by the PTO. The VFO jumper in the back of the radio is there, I actually took it out and dabbed it with deoxit before I put it back in, cleaned all connectors inside the rig, checked for loose components but the display still shows the MHZ 00. first digits off on a couple of bands, the KHZ .000 are accurate on all bands. Radio is functional and as long as I know which band I'm in I'm ok with that. I will gather more information for a while before I decide to go any further, I've been recommended to check caps and diodes inside the enclosed VFO which I will do later on sometime and will post the results.
>  
If the KHz digits read right, there no problem with the jumper or inside
the PTO. The MHz digits come from diodes on the bandswitch.

Look at page 3-29 for information on the presets. That page says lack of
MHz digits is not from the lack of presets. It shows how to test the
presets.

The MHz digits staying zero says the last stages of the counter in U5
are not counting after reset. Hinting at a bad chip or loss of signal
coupling from the output of U4 as shown on page 3-30, 81246 logic board.
or something with the parallel transfer through the 74LS244.

> Thanks all for the help, Gil
> 
> 
73, Jerry, K0CQ