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Old April 4th 09, 02:30 AM posted to rec.radio.amateur.antenna
[email protected] jimp@specsol.spam.sux.com is offline
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First recorded activity by RadioBanter: Jun 2006
Posts: 1,898
Default vertical antenna loading coil vs toroid

wrote:
On Apr 3, 8:22Â*am, Cecil Moore wrote:
wrote:
Did you ever try to model a resonator where the coil required is
actually longer than the insulator, so that the vertical part of the
resonator is actually inside the coil , ...


Never modeled it but have seen its effects during
75m mobile shootouts. One fellow had a hamstick
with the stinger bottom extending down into the
hamstick loading coil. It was a very lossy
condition which improved when he hack-sawed the
excess stinger off.

Do you have EZNEC? If so, I can modify a helical
loading coil to extend the stinger into the middle
of the coil and send the file to you.

Conductors within the loading coil field lower
the effective coil Q. However, I have had good
luck with a 1.25" fiberglass pipe running through
the center of the coil providing mechanical
support. Perhaps you could consider swapping your
insulator for a piece of fiberglass pipe or rod.
--
73, Cecil, IEEE, OOTC, Â*
http://www.w5dxp.com

I have the top portion of the antenna put togather, ready to go up in
the next couple of days depending on wx, after I got it put together I
realized that when I got the toroids I was only concerned about 40 &
80M, and then wanted 160M, should these be some what acceptable on
160M with 100watts Their red on the inner, outer, and top, the bottom
is some color of a green or brown. It measures very close to 26mm
outside,15mm inside and 10mm high. No markings what soever. Any
thoughts on if it should work or not. thanks 73, brett


They aren't usually color coded on the "bottom".

If they are iron-powder, red is material #2, which is good for .5 Mhz
to 10 Mhz.

The size seems closest to T-106, which in inches is 1.060 X 0.570 X 0.437.

You can find all the specs, charts, etc. at:

https://www.amidoncorp.com/


--
Jim Pennino

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