[Fourlanders] 222 Bandpass filter needed

[Robin Midgett K4IDC]

It looks like the F-197 is the filter of choice if someone has one 
available in your area:
http://www.fairradio.com/catalog.php?mode=view&categoryid=202

At 08:01 AM 11/25/2008, Rogers, Ron wrote:
>Thanks, Brian.
>
>Does anyone know if someone has actually modified the military F 
>Band cavities up to 222 MHz and what it took to do that. IF you had 
>to lengthen the cans, that would be tough. If you can simply 
>lengthen the plunger, then maybe that would be easier.
>
>Robin,
>Do you still have any of the 220 cavities ?
>
>
>Ron
>WW8RR
>
>
>----------
>From: Brian McCarthy [mailto:rfacres at gmail.com]
>Sent: Tuesday, November 25, 2008 7:36 AM
>To: Rogers, Ron; Robin Midgett
>Cc: Bob Lear; fourlanders at contesting.com; Gary Bailey
>Subject: Re: [Fourlanders] 222 Bandpass filter needed
>
>I believe Robin, K4IDC, had quite some pile of 220 cavities that he 
>was trying to or helping to sell. I am not sure if any of those are 
>still available.
>
>At Fair Radio they still have some of the F band dual cavities that 
>should be modifiable to 222.
>
>See: 
><http://www.fairradio.com/catalog.php?mode=viewitem&item=3872>http://www.fairradio.com/catalog.php?mode=viewitem&item=3872
>
>They also have some Celwave 220 cavities.
>
>See: 
><http://www.fairradio.com/catalog.php?mode=viewitem&item=3886>http://www.fairradio.com/catalog.php?mode=viewitem&item=3886
>
>I would be willing to donate toward whatever solution seems required.
>
>Just my thoughts,
>Brian
>NX9O
>
>On Tue, Nov 25, 2008 at 6:50 AM, Rogers, Ron 
><<mailto:RR124640 at ncr.com>RR124640 at ncr.com> wrote:
>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: 
><mailto:fourlanders-bounces at contesting.com>fourlanders-bounces at contesting.com 
>on behalf of Bob Lear
>Sent: Mon 11/24/2008 10:35 PM
>To: <mailto:fourlanders at contesting.com>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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>
>
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Thank you,
Robin Midgett K4IDC