Mark, NM5K has raised some interesting questions. Time of day and
frequewncy?

We operated almost around the clock with both broadcasting and program
relay. For broadcast, the schedules are based on propagation predictions
and must be published far in advance. The schedule must be followed no
matter how propagation actually turns out. The best likely frequency is
picked for the path. Also scheduled is something in the next lower
frequency band and something in the next higher frequency band. For
program relay, you can make unscheduled frequency adjustments at any
time it is convenient to do so.

Triple space diversity was the method we mostly used. (3) separate
receiving antennas, spaced about 10 wavelengths apart laterally at
40-meters (400 meters) were used to receive all relayed programs. Each
antenna fed a multicoupler so that receivers could be connected without
interaction.

The three receivers tuned to a particular program (not necessarily the
same frequency) had their outputs fed to a single TDR combiner (Crosby
or Pioneer). The combiner accepted the best output of the three
receivers and rejected the other two. An operator checked the reception
regularly to see if the signal could be improved by selection of either
the upper or lower sideband, or other means.

The height of the antennas was about 20 meters. High enough for
single-hop propagation over the path at midday on the 20-meter band. We
had fixed height so it had to serve from 5 MHz to 18 MHz at all hours.
For relay, we adjusted frequencies almost 24-hours to pick those
frequencies which were working best at the time and might also be
transmitting in the next higher and/or lower band during changing
conditions For relay we used 3 to 5 KW. For broadcast we used 50 KW and
100 KW. Antennas had about 15 dBd gain on both relay path ends. For
broadcast we used 15 dBd gain on the transmitter. The receiver may have
had a wet noodle for an antenna. If it was good enough for the jammers
it was probably good enough to receive us too.

Mark also wrote:
"I`d bet money the vertical would win on the long paths 95% of the
time."

The vertical has its null directly overhead, and it has its maximum
radiation at low vertical angles from the horizontal. A hazard for the
vertical is low uncorrected soil conductivity benearh the antenna.

Put the horizontal antenna up high and it works with either low
conductivity or high conductivity soils. Low height is the hazard for
the horizontal antenna if you want DX.

Best regards, Richard Harrison, KB5WZI