Hi all,
I agree with Toni observing that a 500 Hz filter is too wide
for serious weak signal work.
I use a Racal 1792, modified with 300 Hz and 100 Hz filters,
followed by an audio (analogic) filter. The 100 Hz one, if
well designed (no appreciable ringing) helps a lot.
I also tried an attenuator in front of the RA1792. In my
location I have no need for it; I prefer to reduce the IF gain.
The first mixer seems tough enough (103 dB 3' order IMD measured).
Vaino, are you sure those RX are not designed for weak signal
work? In my opinion it is VERY good. I also tried many others,
and I keep the RA1792 as my main RX.
73 - Marco IK1ODO
[email protected]
Rivalta, ITALY JN35SA (N 45 01' 25.6", E 7 31' 09.4")
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