[TenTec] Argonaut II/Delta II crystal filters

[Bob Towers]

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