Topband: phase

[K9AY]

from W8JI

> I find that it actually has negative impact on copy when noise (or other
> trash like a pileup) is in one ear and a desired weak signal in the other.
> Maybe that is just how my brain works. Bill Fisher W4AN was good at
> listening two directions at once, and didn't seem distracted. Of course he
> lost the stereo enhancement that he also noted was substantial ONLY if the
> receivers were phase locked and antennas were very wide spaced.
>
---

I have also listened in two directions at the same time, sometimes using the
transmitting antenna as the 2nd antenna. In a contest situation, this has
proven highly valuable -- Beverages are too directive to hear signals from
other directions, and it takes too much time to cycle through multiple
antennas.

Like Tom, I have only occasionally seen improvements in readability using
true diversity reception on a single signal. If I want to copy a
difficult-to-hear station, I use a single antenna and tweak the filters in
the radio. This is the best copy 99% of the time. On rare occasion -- maybe
5 times out of 1000 contest QSOs -- a signal is Q5 in the "stereo" mode, but
not copyable on either of the individual antennas. I suspect this is due to
the summed antenna pattern; maybe there is some neural processing involved
as well.

I have used dual-receive extensively in 40M contesting, often with both the
beam and a Beverage in the same direction. It is not unusual to work, say,
two "G3xxx" stations in row, and hear each one in a different ear. I have
not had enough antennas to do exactly the same thing on 160M, but I
occasionally find it useful to use the transmit vertical and my 40M beam as
the two RX antennas while working US/VE stations during daylight.

The real conclusion from this discussion is the old saying, "you never have
enough antennas." Then you need to flexibly switch and combine those
antennas and feed multiple receivers!

73, Gary
K9AY