On Tue, 05 Oct 2004 09:16:39 -0500, W0UN -- John Brosnahan wrote:
>So I owe K9YC an apology--ASSUMING he is using the 160 watt model.
Apology accepted, although not needed. :) I appreciate the input.
The failure mechanism was the FET, not the relay.
I appreciate all of the responses on this, nearly all of which make sense. But
if, as you
say,
"RF switched preamps are PRONE to this type of problem by their very nature.
The
sensitive FET gets clobbered with RF for as long as it takes the preamp switch
circuitry
to detect the RF and actuate the relay."
why would ARR sell a mast mounted preamp that relied on that and specified it's
performance? ARR's data sheet and instruction sheets say that the unit CAN be
hard
switched IF a suitable pre-keying system is used (virtually all modern
transceivers and
power amps do this, and many transceivers have a pre-delay output). But the ARR
documentation does not make even the slightest suggestion that this method is
preferred over auto-detect operation.
Remember -- when it fails on top of a tower, it can be a very big deal to
repair/replace,
and requires climbing twice -- once to pull it down for repair, once to
re-install it. And
you take your life in your hands climbing a Chicago roof in the winter!
And how is a ham radio product that is designed to go on a tower not a topic
for tower
talk? Did I miss something?
Jim K9YC
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Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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