[CQ-Contest] Bandpass filters for M/S or M/M environment
Marijan Miletic, S56A
s56a at bit.si
Sat Jun 12 17:30:40 EDT 2004
K6XX> Someone commented that one need only use the filters on receive, not
transmit. This is NOT true with many (most?) solid-state transceivers.
The best place for a BPF is as close to the antenna as possible! Coax L/4
shorted section is a cheap solution.
It might involve elaborate 1.500 W TX filters described by DL7AV in #1 issue
of shortlived CQ-CONTEST magazine.
Some older HF transceivers had WB noise level attenuated only 80 dB.
Additional TX BPF helps.
Modern ones route TX signal thru shared narrow amateur band filters. VCO
noise has been considerably reduced lately.
RX only bandpass filters can be made much sharper then 100 W version which
must have low loss and flat SWR!
73 de Mario, S56A, N1YU
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