[Kenwood] TM-2550 PLL problem

Tue, 26 Mar 2002 10:48:43 -0600

Resolder L10 in the RX VCO.

Clif Holland, KA5IPF
AVVid
Authorized Kenwood and Icom Amateur Service
www.avvid.com
1-800-214-5779

----- Original Message -----
From: "Steve Garwood" <[email protected]>
To: <[email protected]>
Sent: Tuesday, March 26, 2002 10:31 AM
Subject: [Kenwood] TM-2550 PLL problem

> I'm having a problem with a TM-2550A - a PLL problem.
>
> When the PLL is unlocked, what checks can be done to locate the source of
> the problem?  The 10.24 Mhz oscillator is running, as is the 39.480 Mhz
> oscillator.  It appears that the mix signal provided through IC-2 is being
> shut down by the unlock switches....  The test point associated with the
RX
> VCO set reads .02 vdc.  Adjustments have no effect.  It appears that the
VCO
> is being shut down by Q14 being biased on.
>
> Is there some way to defeat the "unlock" voltage for testing to narrow
down
> the search, and lastly, are there any common problems that crop up on this
> series of radios?
>
> Thanks for any advice?
>
> Steve
> ===========================
> Steve Garwood, N�CZV / USAF MARS  AFA1GQ
> Attica, Ohio
> [email protected]
>
>
> ===========================
>
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