More on matching -- Xtal filters this time
Joel Kolstad wrote:
Thanks for the help, Andy... I muddled through it (it's a little odd the first
time you've normalized your Smith chart to 1800 ohms and the termination is 50
ohms!) and the filters do work as their data sheets say.
I did find that xtal filters can easily drive a network analyzer nuts... even
for looking at a single frequency, I had to significantly increase the
sampling time well above the default to get a stable display. I'm thinking
this is due to the absurdly high Q of the crystals causing a very long
transient response, thereby necessitating a long sampling time to finally
measure the steady state response.
---Joel
Andy writes:
I liked using the old Telonic sweep generators, with the two big
dials, and a diode detector/scope to scan the filter bandpass.
I don't have one, or access to one anymore, and have to do
it by hand.....
But, what the hell. Retirement gives me a lot of time to
twiddle knobs...
Andy W4OAH
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