[BC] Moseley 6060 STL Transmitter notes.

[radioranger]

You may have only "fixed" your problem temporarily.  Talk with Kevin Winn at
Moseley about the bad SMD capacitors that have been plaguing the PLL in
Moseley PCL 6000 series equipment, both transmitters and receivers.

Steve B.


-----Original Message-----
From: broadcast-bounces at radiolists.net
[mailto:broadcast-bounces at radiolists.net] On Behalf Of jon
Sent: Saturday, May 28, 2005 10:49 PM
To: Broadcast Radio Mailing List
Subject: [BC] Moseley 6060 STL Transmitter notes.


As always, a piece of equipment decides to take a "holiday", during a
holiday weekend. This time it was a Moseley 6060 STL transmitter.

The usual thing happened: No AFC lock. And, of course, the old 505 backup
would not lock either, when the OM tried it.

So, I pile in there, and poke around the PCL 6060. (I spent a few minutes
literally slapping the old 505 to get it going again. A few swift wacks,
and some adjusting of the AFC pot got us back on the air...kind of. The
505 had somewhat low modulation, but I was focused on fixing the 6060. So,
I cranked up the output of the Orban into the 505, and we had a signal
of sorts).

All supply voltages check out. Pop the cover, and the unlock light on the
FMO module is on. Of course, the (stupid) foam mounts are rotted, so the
FMO is just floating around the chassis. Fortunately, nothing was shorted.

With much fooling around, a lot of it trying to find where the previous
engineer hid the manual, I got to work. The reference osc had no output.

Manual found, and after quite a bit more time debugging the reference
oscillator, found out the 3.2 MHz crystal socket had "cold" solder joints.
Fixed that, and all was well.

Good thing I am comfortable working with the 145152P2 PLL chip (Don't
ask, but it had something to do with the phase locked transmitter I
designed and built for a pirate station when 145151s were still brand new.
:-) Statute of limitations are up, so that ok to say. Hehehhe).

So, moral of this story is check TP1 on the PLL circuit (which on the board
is a different TP1 that is referenced in the tuning/troubleshooting section
on the incorrect and annoying manual). If you get nothing, pull the "oven"
off of the xtal and give it a wiggle.

It might save the day, or at least some time.

Hope this all help someone in the future!


Jon


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