"Terry K" wrote in message
oups.com...
Unless the radiating element was decoupled from matching for 100khz and
connected to matching capable of transmit at some other freq? Thence
the need for a tx line in the antenna cable.

I don't claim to know every option available on these things. I have a
Furuno LC-80 Loran c in the basement, it came uninstalled with a boat,
but I never needed to use it nor had it connected for any reason. It
has only 3 pins in the connector, and a big base loading coil.
A relay in there might enable use of the 8 foot glass whip at other
freqs.

Terry K

Well, tx and rx lines are necessary because the antenna module must get
programming data from the display unit. In other words, it must receive (rx)
data from the display, asking for the unit to tune to the proper GRI and
slaves for the area in which it is being used. THEN, the LORAN received (and
decoded?) data must be transmitted (tx) to the displaying unit. The tx and
rx lines give this serial port connection the steering and coordination
necessary to get the job done.
Old Chief Lynn