[Elecraft] K3 Filter selection

[David Woolley (E.L)]

Bill W4ZV wrote:

> 
> 400 and 250:  A waste of money IMHO.  Since the 400 is actually 435 and the
> 250 is actually 370, there is only 65 Hz difference in this combination and
> you'll probably never notice the difference between them (370/435 = only 15%
> narrower).  Total cost $250.

I think you are generalising from a single sample.

It may well be the case that to  guarantee a bandwidth of at least 250 
Hz, without doing expensive select on test procedures for the 
capacitors, one will have some samples at 370 Hz.

What you may be getting is 250Hz with a given shape factor, but 
individual units may achieve that shape factor by going flat to a higher 
frequency and then cutting off much more sharply.

-- 
David Woolley
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