Thread: J Pole
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Old September 4th 06, 01:09 AM posted to rec.radio.amateur.antenna
Dave Platt Dave Platt is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 464
Default J Pole

In article KLHKg.1381$xh4.656@trnddc04,
Amerigo Vespucci wrote:

The skeleton discone sounds like a neat idea.Do you have a diagram or
something for that? Oh BTW I am a ham I am just working with limited
resources at the moment. Call hre is Kilo Alpha 3 Victor India Delta . Nice
to make the aquaintance.


Take a look at the discussion at

http://www.radioreference.com/forums...hp/t-8000.html

You'll see a bunch of different homebrew discone designs there,
including both traditional (solid sheet-metal disc and a sheet-metal
cone) and skeleton (radial rods to make both the disc and the cone).

The Diamond D130J is a commercial version of the latter.

One simple way to put together a discone "on the cheap" - use a block
of wood perhaps 2" in diameter and 2" high as the center insulator.
Drill a 3/4" hole in the center, insert a piece of 3/4" dowel (the
mast) and glue into place. Take 3 or 4 pieces of stiff copper wire
12" long, twist them together in the center, and the ends apart so
that they form a flat disc of radial-like elements, solder the twisted
section together, and mount on the top of the wood block with a couple
of wire staples. Drill a set of 8 holes, angled upwards into the
block at a 45" degree angle, and insert 12" wires or rods (forming the
skeleton cone). Run a length of bare stranded wire around the inner
ends of these wires or rods (right where they enter the block) and
solder. Drill a hole upwards through the block, right beside the dowel.

Now, run your RG58 (or whatever) feedline up the mast/dowel and
zip-tie it into place. Remove a few inches of insulation, separate
the braid from the center conductor, strip the end of the center
conductor, run the stripped end up through the small hole you drilled
and solder it to the junction of the six radiating spokes, and solder
the coax braid to the wire which connects to all of the skeleton-code
wires. Waterproof the end of the coax somehow (paint-on electrical
"tape", perhaps).

You now have a garage-built skeleton discone, akin to the Diamond D130
but a lot less expensive. [Probably a lot less rugged, too, but if
it's just a temporary it should serve you well enough.]

--
Dave Platt AE6EO
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