Re: [amsat-bb] Murata/K5GNA PCB Filter Plots..

[K5OE@xxxxxxx]

Fred,
Thanks for the quantitative & graphical data.  Let me offer a little 
qualitative observation from installing the K5GNA Murata filter in a TSI 3733.

I have been using local MMDS channels to check out various downconverters and 
antennae for a while--more as a "does it work or not?" kind of pass/fail 
test.  I also have used these signals for various kinds of comparison tests.  
The 3733 is a hot little unit for MMDS, noticeably better than a stock Drake 
connected to my now-standard-test-jig (a 16-turn helix pointed at Discovery 
Channel from a second story bedroom window).  After I installed the Murata 
filter, the picture from the MMDS channels (about 2520 MHz) was, well, 
crappy.  It was all snowy and had bad audio.  I immediately realized this was 
due to the sharp roll off of the filter.  The d/c performs very well for 2401 
MHz, as I am using it right now to capture telemetry from AO-40 at  62,000 km 
(lots of synchs but no good CRC's right now at MA=128).  For those that are 
curious, or perhaps think I am kidding, here's a screen shot that I use as a 
consistent test pattern for my not-quite-the-way-the-professionals-do-it 
comparative analysis:

http://members.aol.com/k5oe/mmds.jpg

73,
Jerry, K5OE

fspinner@hotmail.com writes:

> It's been awhile since my last insanity.  I decided to check the K5GNA 
>  PCB/Murata DFC22R44P084BHD Dielectric filter.  Also, I editoralized a bit 
on 
> 
>  the page, and overall the filter board looks like a good board for the 
AIDC 
>  3033/3733 and probably the Drakes as well.
>  
>  Network analyzer plots are at:
>  
>  http://members.home.net/fspinner/W0FMS/Murata
>  
>  or as always through the:  http://w0fms.org  "domain-reflector"
>  
>  Fred W0FMS
>  
>  _______
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