[R-390] Mechanical Filter Failure?

[Jon Schlegel]

Hi guys and gals,

I'm working on bringing up an R-390A and have no response through the 
2 kHz mechanical filter.  It's my understanding that the usual 
failure mode for these is an open coil on the input or output yet I 
measure 40 - 50 ohms DC on both input and output of the 2 kHz 
filter.  Checked the rest of the signal path around the filter 
especially the rotary switch and all checks ok.  Is there anything 
else I should look at before thinking about finding a replacement?

Regards,
Jon, WA3MVM