[R-390] Diagnostic Help Needed (Part 2)

[Tim Shoppa]

Joe Connor wrote:

> I was fooling with the set some more and got something very weird.
>
> 1. At around 8.0 mhz I got a station (foreign language).
> Audio was good but the station stayed on over about 60
> khz as I rotated the KC control. When I get the garbed
> station at 780 khz, it stays on over about 20 khz as I
> rotate the KC knob.

PTO shaft is not turning (or not turning enough) as you turn
the tuning knob. Either a loose setscrew, or a missing oldham
coupler, or the PTO leadscrew is jammed up against its
ultimate limit, or the zero set is engaged (purposeflly uncoupling
of loosening the coupling between knob and PTO shaft), or the
grease in the zero set clutch isn't transferring motion,
or a combination of the five.

It can be really disconcerting to turn the kc tuning knob and
all the RF deck clockwork turns... but underneath the radio the
PTO shaft doesn't turn!

Tim.