[R-390] kilocycle/megacycle movement

[Dan Merz]

Hi,  I haven't used my  390a much over the last 2 or 3 months and I was
listening on 80 meters tonight and found a problem tuning up near 4
Mhz.  It seemed dead there and I could tune in stations down near 3.9
somewhat better (I started listening on another set for comparison to be
sure the band wasn't dead).  After awhile I noticed that the megacycle
knob seemed to move off its "lock" position and was moving as I tuned
the kilocycle knob.  It did this sometimes and would get off the band
position but not always.  Is this most likely a lubrication problem?  I
really never was able to pick up a known signal at around 3.99 Mhz and
I  tried rocking the megacycle knob to improve things,  or to find if
something else was "hanging up".  I haven't lubed the set since about 2
years ago when I did a pretty thorough job in this regard and everything
seemed very free.  I'll pull it open tomorrow and take a look but was
curious if there was an obvious known component that causes this kind of
symptom. It seemed ok on other bands but I didn't spend a lot of time
checking.   thanks,  Dan.