Richard Fry wrote:
"I also vaguely note some inference of peduliar intermodulation products
that would be produced by a transmitter with 50 Ohm output
characteristics---"

First transmitting plant I worked in back in 1949 was that of KPRC /
KXYZ. These each used an RCA 5-C. Transmitters were 250-watt exciters
driving 5 KW water cooled linear final amplifiers. The interesting thing
about this plant was that the 950 KHz and 1320 KHz transmitters both fed
a common main antenna. Each station had its own directional tower on the
side.

The way to avoid intermodulation is to keep the foreign signals out of
the electronics so they don`t mix. Well designed and adjusted
pass/reject fikters in the transmission circuits of KPRC and KXYZ saw to
that.

Best regards, Richard Harrison, KB5WZI