[TenTec] Omni 6+ PLL troubleshooting (was: Help with Omni 6+ rx warble)

[Barry N1EU]

I've finally got the chance to get the Omni 6+ on the bench.  After
replacing a very intermittent C31xtal oven trimmer, I started looking
closer.

I'm getting a rx "warble" now at about a 2hz rate.  If I put a scope
probe on the logic board PLL chip (U13), I see blips on pins 14 and 15
(phase/freq detectors) in sync with the rx warble.  I'm pretty
clueless on PLL circuits.  I'd appreciate any advice on how to proceed
with the troubleshooting.

Also, where is the 5Mhz PLL Board and the Xtal Osc/LO Mixer Board?

Thanks & 73,
Barry N1EU

On Wed, Nov 2, 2011 at 9:37 PM, Barry N1EU <barry.n1eu at gmail.com> wrote:
> I'd appreciate some help troubleshooting a pronounced hitch or warble
> in the received tone, happening regularly about every 1.5 seconds.  It
> occurs in cw, lsb and usb.  Please have a listen - this is 10 sec CW
> plus 5 sec USB tuned to a carrier:
>
> http://n1eu.com/omni6_warble.mp3
>
> Can anyone provide some helpful troubleshooting tips?
>
> Thanks & 73,
> Barry N1EU
>