john, ke5c wrote:
> Has anyone experienced low output on 21 mhz (380 W) with normal output on 14
> mhz (520 W)?
I can't give you a definitive answer about the sgc, but I can tell you
that my experience with the Henry SS750HF (8 x 2sc2879) is that the
output is very dependent on the impedance seen by the amplifier, and
possibly the nature of that impedance (e.g., how much reactance and the
sign thereof). My amplifier puts out 100 watts less into my antenna
(SWR about 1.4:1) than the dummy load on 20 meters; on 15 with a similar
SWR the situation is reversed and it seems to be capable of more power
into the antenna than the dummy load.
If you want to check the lowpass filters you can disconnect them from
the combiner, put a 50 ohm resistor across either end and use an MFJ259
or similar antenna analyzer to sweep across the range and see how the
SWR changes.
If the sgc is like my amp, there will be a decline in output as
frequency goes up. How does it work on 24/28 MHz?
73
Vic K2VCO
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