[Fourlanders] 222 Bandpass filter needed

[Rogers, Ron]

I don't know if I have anything here, Bob. But I will check.
I will also research to see if there have been any articles published about 220 filters and cavities, as such.
 
Or maybe find an old 140 - 150 MHz VHF cavity and see if it can be cut down to 220 size.  I'll bet even a tunable Hi-Q helical coil filter design would work for this situation.
 
Ron
WW8RR
 
________________________________

From: fourlanders-bounces at contesting.com on behalf of Bob Lear
Sent: Mon 11/24/2008 10:35 PM
To: fourlanders at contesting.com; Gary Bailey
Subject: [Fourlanders] 222 Bandpass filter needed


This is regarding the recent problem with the WA4IOB 222 beacon which
has been shut down since the spur problem.  I ran into Gary at the Stone
Mountain hamfest and we discussed the situation.  He said a filter will
probably solve the problem and he has a network analyzer with which to
tune one if we can come up with a suitable filter for him.

I thought I had one, but it turned out to be too high in frequency.  I'm
still looking in the mess I'm making while moving and losing stuff left
and right in boxes here and there!!  I did find some military 'D' Band
dual tunable cavities that are for 400-450 and 450-500.  Gary said that
type device would work if they cover the 220 band, but I know these I
have aren't going to work at 222.  Does anyone on the Fourlanders list
have something suitable?  I'll try here first and if we don't come up
with something, I'll try the SVHFS list next.

Thanks for checking.  Let me or Gary know what you have to help the
situation.  We'd like to the the 222 beacon back on the air.

73, Bob
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