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RE: TranSystem & Murata filter



Interesting comment Howard. I obtained a TranSystem unit from Bob Seydler
K5GNA and picked up the Toko filter at the same time. Went through a process
similar to yours (did not change from 122 MHz out) and found improvement
with
every step.
Now I find a report to leave the input filter in place - too late!
I did not use a PCB for the filter rather kludged up an installation using
bits of the removed second filter.
Performance compares favourably with CalAmp & NorSat units ex-Mark Fossum.
I had already fully converted a Drake to the <2db NF status with a Murata
filter and again the TranSystem unit compared favourably. Bench tests using
a low level noise source for comparison purposes put the units in order of
performance - Fully modified Drake, CalAmp, TranSystem, Norsat. (Both the
CalAmp and NorSat have had the PTFE tape modifications - simple and VERY
effective.) Not much to pick between the last three but the Drake stood out.
There may be reasons for that which will probably become apparent when I do
on-air comparisons now I have my antenna in place.

Not a lot of help with your current problem but I trust it gives you hope of
having an excellent unit performing correctly.

73, Terry,   ZL3QL.

>From Howard Long>>

I've been gradually modifying a TransSystem AIDC-3733 today.

4) Inserted Murata filter - lots of S7 noise still, but VERY DEAF (-30dB or
worse compared to before)!!!


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