[Collins] testing 51J4 filters?

[eugene at hertzmail.com]

Greg and DW. I didn't know if I needed to provide any DC bias somehow to
do this. Sounds simple enough to test! If I am looking at the rear of
the filters (pins facing me) which are the input pins and which are the
output pins? Left to right? Right to left? Top to bottom?

Also, my RF generator has 50 ohm output. Is this sufficient? Or do I
need to change the impedance in any way? 

Thanks!
Eugene W2HX


-----Original Message-----
From: Greg [mailto:bluebirdtele at embarqmail.com] 
Sent: Wednesday, November 14, 2007 9:14 PM
To: eugene at hertzmail.com; collins at mailman.qth.net
Subject: Re: [Collins] testing 51J4 filters?

Sure:

Pump the IF frequency into the filter via the signal generator and use
the 
oscilloscope probe at the output pin.
You should see a signal on the scope around the IF freq but much lower
in 
strength from the input side.
This should answer the "likely to work" question.
You can do this same test with a quartz crystal too.  The Q is so
freakin 
high with quartz you have to tune very slowly in order to catch the
scope 
response and I wouldn't sweep it with a squiggly kind of generator.
Have fun!
Greg
WA7LYO
Kinston NC

----- Original Message ----- 
From: <eugene at hertzmail.com>
To: <collins at mailman.qth.net>
Sent: Wednesday, November 14, 2007 8:41 PM
Subject: [Collins] testing 51J4 filters?


Hello all,

Finally found a 6.0kHz mech filter for my 51J4 (also got a 1.4 too).
Problem is, my 51J4 is inoperative presently. I was wondering if there
are some simple tests I could perform on these filters that might tell
me either they work, or are likely to work? Or perhaps that they are
dead? Test equipment available includes rf generator, scope, hp410B
meter. Are there some simple tests I could perform?

Thanks
Eugene w2hx

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