David Olean <k1whs@worldpath.net> wrote on Thu, 14 Aug 2003
at 14:40:04 +0100 in <00d901c36269$92dcfc30$37c07f3f@DGL28221>:
> Comparing a modern version DEM transverter and good modern HF radio with a
> Yaesu 736 is like including Arnold Schwarzenegger and Pee Wee Herman in the
> same class (humans). Assuming that you are not a cheapskate, and get decent
> coax, there is no need to tower mount preamps on 144 or even 222 with a DEM
> transverter. A preamp will just kill your overload capability. If you have
> to run more than 100 ft of coax, and it isn't 7/8" on the higher bands,
> maybe a low gain preamp could help. Shoot for 1 dB feeder loss. 3 dB loss
> starts to be real bad.
Our experience at W1XM, high up in RF noisy Boston (albiet with a
736R), is that a preamp on 2 meters is incredibily valuable, even with
an 80' run of heliax. However, it is necessary to front the preamp
with a cavity filter. Remember, you can always turn the preamp off...
--jhawk
KB1CGZ
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