"Bart Bailey" wrote in message
...
In Message-ID:lkQdg.27874$QP4.7530@fed1read12 posted on Fri, 26 May
2006 21:12:01 -0700, Sal M. Onella wrote:

The training aids for the EMI
Awareness course I used to teach at San Diego Naval Station (command =
FTSCPAC, if you know that outfit) included a funky little plywood ship,
within which were two milliwatt-level HF "transmitters" and a receiver.

Was that what was called the model pond, has a chocolate chip looking
tower arcing out over it, very unusual sight from the road?
I had a friend Charles Roy WS6F (now SK) that used to work there.

No, but I know what you're talking about. (The demo I did for class was a
desktop affair -- kept in a suitcase between classes) You're probably
referring to the model range(s) at Naval Ocean Systems Center (NOSC) on
Point Loma. NOSC was consolidated, I think, into Space and Naval Warfare
Systems Center, San Diego.

For those not familiar with this process, they used brass ship models, both
existing and proposed, built to 1/48 scale. They were on a lead (Pb) "sea"
at least 100 feet across. At the center of the "sea" was a turntable, on
which the model could present any aspect to the tower you refer to. The
tower supported a log periodic antenna which could be raised along a curved
arc from the horizon up to the zenith, overhead the model. Picture about
halfway down the page at

http://www.spawar.navy.mil/sti/publi...d/1940/photos/

The model ship was fitted with scale antennas, complete with coax that ran
down through the turntable and into the control room. For any given antenna
and location on the model, the engineers could get a three-dimension Antenna
Radiation Pattern at scale for a good idea of how it would work in the real
world. ... and I understand it was quite reliable. 96 MHz scale was 2 MHz
real-world, and so on. I think the LPA did all the transmitting, but I'm
not positive.

I got a guided tour of the range once in the 1980's when I was in their
building for an unrelated conference. (It was more interesting than parts
of the conference, but that's another story.) I wonder, do they still model
antennas this way?

A few of the brass models were regularly on display, visible from the road
about ten feet behind the fence, for many years. It has been five years
since I did any work on Point Loma and I don't know if any models are still
in public view.

73,
John