[R-390] AGC Voltage

[David Wise]

This is another well-known problem.  The disk stack inside your
mechanical filter was originally positioned and cushioned by
foam inserts.  The foam has disintegrated, and the stack occasionally
contacts the casing.  I couple of people have opened these up
and repaired them.  They have written up their experiences on
the web.  Search the forum archive for "filter".

Regards,
Dave Wise

> -----Original Message-----
> From: r-390-bounces at mailman.qth.net
> [mailto:r-390-bounces at mailman.qth.net]On Behalf Of Mike Hardie
> Sent: Sunday, September 28, 2008 8:32 AM
> To: R-390 at mailman.qth.net
> Subject: [R-390] AGC Voltage
>
>
> First of thanks again for all the terrific suggestions.
> Yesterday (before
> seeing some of the suggestions) I unsoldered the top terminal
> wires from the
> 16 Kc filter and connected up the ohm meter to the other filters top
> terminal "common".  Turning the IF deck over and over the
> problem did not
> repeat.  To confirm the fault was in the 16 Kc filter the ohm