On two stations on the same band at the same time, or same subband, many of
us do this every year in FD with a station on CW, another on SSB, and
sometimes a third one on RTTY/digital. There is some interference,
sometimes too much, but most of the time it's manageable -- that's at the
150 watt level. We make a point of separating, for example, our 20 CW and
20 SSB antennas as far as possible and have them "broadside," pointed west.
In a DX contest it would make sense to have antennas broadside to Europe --
this could be done.
One time in FD K3RA was on 20 CW. Things got a little slow so he went to
check 15 and 10. I was in the next chair doing 40 CW, which had gotten slow
to, slower than 20 CW, so for fun I figured for a few minutes I'd fill in on
20 CW, but didn't mention this to K3RA, just did it. After a while he came
back to 20 CW, not realizing I was there, and began CQing 5 kHz up from
where I was. I sent him a gab message on CT but he didn't see it. Sent
another. I was amused to realize we were so close to each other, both on 20
CW, and neither could hear each other's signal at 5 kHz apart.
Interestingly, he immediately established a QSO rate equal to what he had
had when he left 20, which I had maintained on 20 while he was gone -- and
my rate on 20 stayed at that level too. That is, we doubled our 20 CW rate.
These were not dupes. A different group of callers were answering 5 kHz up
than were answering 5 kHz down. So, let's say we'd been running 30/hour on
one station. Our combined rate went to 60/hour.
I finally got K3RA's attention, we laughed about it, he carried on and I
went back to 40.
We realized that FD rules do not allow two stations on the same subband at
the same time, so we didn't do it any more. (I hadn't realized it until
after our overlap -- and I hadn't expected our overlap to last long because
I figured he would immediately realize he wasn't alone on 20 -- it lasted
for a few minutes because I was astounded that we could co-exist with not
even enough interference for the other to know the other was there!). It
was an interesting discovery or experiment.
Suffice to say, it is possible to have two signals in the same subband at
the same time and "survive." With specialized receiving antennas (e.g.
beverages), antennas at a distance and/or intentionally pointed in the
less-interference-prone direction, it would be quite do-able I think, even
at 1500 watts. Well, that's what W3LPL has -- the mult-hunting second
station on a band listens on beverages while the run station CQs -- and the
second station can generally hear even when the 1st station is transmitting.
And I think Frank has also tried putting a tribander on a portable mast at
the far corner of the available land. I suspect many others do these things
too.
73 - Rich, KE3Q
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