[TenTec] Argonaut II/Delta II crystal filters

[Bob Towers <mm0rkt@beeb.net>]

I'm not exactly happy with the Jones filter on my Argonaut II.

a) the centre of the bandpass shifts up frequency (on USB) when I 
tighten the bandpass width
b) the narrowest width setting is about 700Hz: I could do with 500Hz or 
narrower.
The manual warns against adjusting the two sets of 4-pole filters unless 
you have a network (spectrum, surely?) analyser, which I do. Anyway, the 
adjustment pots are all locked in position with some sort of fixative.
Has anyone had a go at adjusting the filters?

If so, I would appreciate some advice - which might be, of course, don't 
try and fix it!
73

Bob
MM0RKT