> From: Andy <ai.egrps@gmail.com>
> The one near me is W1EVT.
>
> Someone mentioned on an email list that they haven't heard from W1EVT yet
> this year. I don't know anything about him or his station other than the
> few mostly anecdotal stories I've read. His antenna may or may not have
> been a Sterba curtain, the government may or may not have had an
> interest in it, his feedline is claimed to be thousands of feet of open wire
> that runs underneath the street, and his callsign might have changed over
> the years.
I can fill in some of the blanks.
W1EVT's antenna system consists of stacked dipoles for each band on a
total of 18 towers (there is a 19th, but I don't think it has anything
on it. I seem to recall he had a small beam on it once for testing.
About once every two years the local Boston newspaper answers a
reader's question about his antenna system ("Is that some kind of
top-secret military installation next to Route 2?").
The 18 towers are all about 120 or 140 feet tall, all Rohn 25. The
towers for each band are arranged in equilateral triangles, and hold
stacks of dipoles, fed with binomially-weighted currents. For example,
on a band with 3 stacked dipoles, the top and bottom dipoles are fed
with I, and the middle is fed with 2 x I. I think some bands had 4
(fed 1:2:2:1), and maybe 10M had 5 (fed 1:2:3:2:1).
Having 3 sets of these stacked dipoles, each with about 60 degrees of
(bidirectional) pattern, affords full azimuth coverage with fast
switching. I suspect the story about his antenna system being used for
covert military DFing is an urban legend, since fixed-position dipoles
are probably not the best antennas for that purpose.
Yes, the main feeders are open-wire run in a conduit under the street,
since the antennas are in a pine forest across the street from Clem's
house. Clem has/had an extensive TDR setup for troubleshooting faults,
since branches fell on the feeders out in the woods frequently. He
could figure out where the fault was with his TDR, then walk to the
exact spot and fix it.
As I recall from my visit there, he had a homebrew transmitter but
some state-of-the-art commercial (non-ham) receiver. He may have moved
to commercial ham gear now.
Clem held the callsigns KF1Z and NY1N between his two periods of
holding W1EVT. I saw him last spring at the MIT flea market, but have
not heard him on the air much. Best time to listen has always been
around sunset in the winter, working JAs long-path on 80M.
He holds a Ph.D. in Physics from Harvard, and his dissertation was on
"Coupled Receiving Antennas". When I visited him, he was running a
small company in his basement manufacturing very high-voltage
transformers, using epoxy potting of his own formulation and an
ingenious home-brew vacuum pump to evacuate voids in the potting.
73,
Doug K1DG
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