I would like to build a power meter with a combined dummy load for
my QRP station. I have 2 200uA meters, and would like to use one to
display forward, one reflected (continuous), with no "calibration"
needed. The meters are a 0-4+ scale, so calibration would be fixed
in three switchable ranges: scale, scale/2 (two watt full scale)
and scale*2 (8 watt full scale). The dummy load component would
also be switchable in and out, with a pickoff circuit to connect a
scope or freq. counter.
I've checked my 1990 Handbook, and QRP classics, with no help. All
the circuits there utilize a single meter and some sort of "cal" to
measure SWR.
Private e-mail ok, if this topic wouldn't be of interest to the
group. I have two articles from Hambrew mag, Spring 96 and Fall 95,
both by Bill Hickox of Tejas Kits, K5BDZ, but can't figure out the
metering on the SWR/Power meter, nor how to modify the ranges via
switch. Nor can I determine the input vs. pickoff circuit on the
dummy load.
72 es 73 de
Marty, KM7W
____________________________________________________________________
Jackson, Tennessee e-mail: mdwatt@usit.net
http://www.public.usit.net/mdwatt
"The Curmudgeon's Corner"
NorCal - QRP ARCI #7514 - QRP-L #953 - AK/QRP #098 - Grid Sq EM55oq
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