The shakesphere 222 is not loaded, the bottom section has four copper
straps buried in the fiberglas (as I remember).
During my active duty in the Coast Guard, I've seen the 222 used on both
ship and shore units for 1.6 - 30 MHz with either an automatic tuner or
with a multi-position (pre-tuned) coupler. I think a couple of short
range MF radio beacons (300-400 kHz) radio beacon installations used this
antenna as well, but the antenna was chosen to REDUCE field strength to
the allowable limit (a long story for another time). The typical power
level was 100 - 1500 W. The differences in the 222 models are in the
feed mechanism. One method used the flanged base as the connection ...
this antenna was designed to be mounted on a matching base insulator
about 8 inches high. The second version had the antenna element
connection come through the base flange (you mounted this one on a steel
box with an access hole to make your connections. The third style had a
3/8-24 threaded insert about 2-1/2 feet up from the base ... you
connected your feedline to this with a bolt. Of the three, this one is
the easiest to use.
I'd mentioned in an earlier post about installing one on the top of an
aircraft hanger in Sacramento, CA ... with the huge groundplane
available. Worked well to say the least.
I no longer have the Shakesphere data sheets, you should be able to get
them directly from Shakesphere.
I'm not as familiar with the 4250-1 ... and I've learned not to guess at
these things!
Good luck & 73!
Rick, WB3EXR
On Sun, 14 Jun 1998 21:37:20 -0230 "Gus VO1MP" <gussam@newcomm.net>
writes:
>
>
>Shakespeare Heavy Duty Fiberglass Rigid Tubular Vertical resonators:
>
>I Have recently acquired several heavy duty Rigid Marine whip type
>antennas
>that should easily be adaptable for amateur use ???.
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