[R-390] Symptoms of a mechanical filter failing?

[jgedde at optonline.net]

G'Morning,

 

On my R390A, the 2 kHz bandwidth is acting weird intermittently.  With a
strong signal it works fine, but it works strangely with weak signals.  I
get a high frequency oscillation or the radio loses almost all sensitivity.
It's kind of like a squelch if a detune a carrier.  It goes from receiving
the station just fine, to a squeaky oscillation or no signal at all.

 

I'm thinking it could only be the filter or the BW switch, but I'm leaning
toward the filter.  Whaddaya all think?  Is it time for a foray into the
guts of my 2 kHz filter for repair?  That'll be a first for me, but
thankfully a repair procedure has been well documented online.

 

Thanks!

John