[R-390] If alignment and low signal

[FISCH, MICHAEL]

Hi:
 
I am finally getting close to completing my R-390a fix up.  Last night I was aligning the IF.  I would think when I put 455 kHz into the module (per wisdom, etc.) that the voltage on the diode load should be approximately independent of bandwidth for 2-16 kHz (thats as far as I am) 16 and 8 kHz are close, 4 Hz is about a factor of 4 smaller and 2 kHz an other factor of 2-4 smaller.  The tunable caps seem to have minimal effect on these last 2 filters; however, the width of the filters seem about right.  My guess is the silver mica caps need to be changed.  Is that the correct diagnosis?  Also will 500V capacitors work? 
Thanks
Mike