The real killer with trying to use a 45mhz crystal is that it will almost
certainly be an overtone crystal.? And I believe it would not
be suitable as a filter at other than it's fundamental frequency.
This ebay ad for some 45mhz filters similar to what is stuffed at Y1
? ??
Note that they are selling "matched pairs".
That suggests to me that if you buy a 45mhz filter off ebay it may not match
the frequency of what's already installed at Y1.? So buy two, preferably matched.
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On Wed, Sep 5, 2018 at 09:17 PM, Jerry Gaffke wrote:
It's not a given that some 45mhz quartz crystal from ebay patched in using Raj's instructions
for a filter module will just work.
?
Perhaps the series resonant frequency won't quite agree with Y1.
Impedance matching may be an issue.
May have a very high insertion loss.
Most forum readers don't have the tools to plot the passband of their new filter.
