[R-390] A vs non A

[Charles P. Steinmetz]

Roy wrote:

>I seem to remember an alignment procedure that uses slightly offset
>frequencies to stagger tune the non-A IF system.
>I cannot find it however.  Does anyone know where that is, what
>manual?

I have seen several procedures that purport to achieve stagger tuning 
in 390 IFs by peaking different adjustments at different 
frequencies.  However, in a properly stagger-tuned IF all of the 
stages will be symmetrical about the nominal IF frequency (in 
practice, this will be the center frequency of the crystal 
filter).  Some stages will exhibit peaked responses, while others 
will exhibit two peaks with a valley between them.  No procedure that 
requires only peaking will get those right.  I've done it using sweep 
tuning, but it is not something I'd recommend to anyone who doesn't 
have a sufficient understanding of cascaded filter responses to 
design the IF from the ground up (and also has a fair bit of time on 
their hands).

Best regards,

Charles