[amsat-bb] AIDC 3733 Filter Info

[K5GNA@xxxxxxx]

 >From K5GNA:

Many of you have been ordering the Murata filters from me.  Please check out 
their specifications (size) before you attempt to order one and install it.  
See link below. 

If you replace the first filter in the AIDC 3733 with the Murata, you will 
degrade the noise figure by its insertion loss (greater) over the loss of the 
original filter (lower). Replacing the first filter will also require test 
equipment to get it back to best noise figure -- which will be worse than 
when you started because of the additional insertion loss. 

Replacing only the second filter (closest to the mixer), the small extra 
insertion loss will not really count in the NF and will provide enough 
rejection.  According to the spec's on the curve, the 2 meter image rejection 
is at least 35 dB and the rejection at the LO is at least 20 dB.  This single 
filter will do the job and you will have a true 1.4 dB or greater SSB noise 
figure.  I WOULD RECOMMEND REPLACING ONLY THE SECOND FILTER.  

MURATA MODEL DFC22R44P084BHD FILTER SPECIFICATIONS 

http://search.murata.co.jp/Ceramy/owa/CATALOG.showcatalog?sHinnmTmp=DFC22R44P0

84BHD&sLang=2&sNhnm=DFCH22G44HDHAA&sHnTyp=OLD



TNX & 73,

Bob Seydler
K5GNA

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