Regarding the tuning when going from CW to SSB, I have an 80M (and a 160M, 2
separate antennas) 4 square (per ON4UN) using single raised radials on each
element about 15' up using the DX Engineering box (but the same applies to
Comtek). I have remote relays to subtract length on SSB because you really
need to keep the "dump" wattage low to maintain gain and F/B in each segment
of the band. Sure, the SWR is great across the entire band with a Comtek
box and no tuning consideration but your gain drops significantly if you
don't compensate somehow. With 1500 watts to the antenna, I like to keep
the dump below 10 watts and generally below 5 watts. My 160 4SQR is about
twice that amount since it has wire elements rather than Rohn 20 like my 80M
4SQR. If I have the wrong radial length chosen, the dump wattage goes well
above 75-100 watts and I know I'm not getting the gain and F/B I expect.
ON4UN explains it much more elegantly than I am but I just had to comment on
the SWR statement which didn't mention "dump" power at the same time.
Basically, ON4UN's point is, tune the 4SQR with dump power minimization as
your prime concern to get maximum gain and F/B.
73,
Bob K5WA
>>>>>>>
Initially, I switched
in some linear loading when going from SSB to CW. This arrangement was
abandoned when I didn't experience any TX or RX detriment by just using it
without the loading all the time. Realize that the Comtek phasing box will
broadband the array by absorbing any mismatch in the 100W port resistor.
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