"Larry" wrote in message . Killer. The very-low frequency
LORAN antenna is electrically 2340' long
(1/4 wavelength on 100 Khz). To achieve this in an 8' long whip it is
VERY heavily loaded with a large inductance and that coupler. No, you
can only get it working with the cou0ler or a 2,340' long whip, your
choice.


2. Are there marine LORAN receivers which don't require external
couplers (i.e., that hook direct to the antenna)?

The couplers on the marine antennas are built into the whip. They're
still there.


3. If you have a marine LORAN which does in fact need an external
coupler to get enough signal through and you don't have the companion
coupler unit, are any commonly available pre-amp boards for the LORAN
frequencies available? If so, where find?


It's not a preamp problem. There's tons of signal from teh MEGAWATT
LORAN-C pulse transmitters and their massive capacitor hat loaded 850'
tall antenna towers. The problem is that 2340' 1/4 wave whip it takes to
hook 'em up.

You need the antenna system it came with.....

While there is certainly no question that the matching coupler and 8' whip
are pretty much standard, just for fun we experimented with some of the old
TI lorans, and found that the SSB antennas on many power and sail boats
worked fairly well, with one major "gotcha". Loran C, at 100 khz is very
easily messed up by electrical noises from almost anything on a boat. Having
the 8' whip antenna up and away (several feet at least) from the noise
makers and the boat's wiring, made major differences in noise pick-up. Water
damaged TI loran couplers were pretty common, and you could pull the guts
out and throw them away, and jumper the whip connector to the signal feed
wire inside the coupler. Performance not perfect by a long shot, but if you
shut down the main engine and everything else, you could get a fix. (the
hard way)
Old Chief Lynn