MGFoster wrote:
Cecil, I'll work w/ your s/s and play around some more w/ the helical
(just for the fun of it, ya know ;-) ).

You will radiate more power if you make the center half
of the antenna straight wire and use the ends of the
antenna for the helical part. If you haven't considered
top hats on the antenna ends, please do so. The following
would be a pretty good antenna, in fixed font with top
hat loading at the ends.

| coil coil |
+---////////--------FP--------////////---+
| |

--
73, Cecil http://www.w5dxp.com

Cecil Moore wrote:
MGFoster wrote:
Cecil, I'll work w/ your s/s and play around some more w/ the helical
(just for the fun of it, ya know ;-) ).

You will radiate more power if you make the center half
of the antenna straight wire and use the ends of the
antenna for the helical part. If you haven't considered
top hats on the antenna ends, please do so. The following
would be a pretty good antenna, in fixed font with top
hat loading at the ends.

| coil coil |
+---////////--------FP--------////////---+
| |


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Hash: SHA1

Isn't that a linearly loaded dipole?

I saw a picture of a similar antenna in some book I was browsing - the
illustration didn't show a center wire, just the coils and the top-hats.

Would you keep the wooden dowel form (for the coils), or would you let
them be air-coils (how to keep them from separating [tape])? What
lengths would you use for the wire/coils? What type feed line would you
use: twin lead or coax? Am I asking too many Qs?

Wait a minute... I've seen examples of this type of ant. on other
websites. I'll look those up and you won't have to answer these Qs,
which have probably been asked many times before.

N5ESE shows a linearly load dipole that is about 12 feet long (6 ft per
pole), twin lead fed with 14 inches of zig-zag wire at the ends. He
reports that he had pretty good results w/ this ant. on 15M and 20M (the
ant. was inside his bedroom at the time of the test).

http://www.io.com/~n5fc/notebk_ant.htm

Thanks,
--
MGFoster:::mgf00 at earthlink decimal-point net (KI6OFN)
Oakland, CA (USA)
** Respond only to this newsgroup. I DO NOT respond to emails **

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MGFoster wrote:
Cecil Moore wrote:
| coil coil |
+---////////--------FP--------////////---+
| |

Isn't that a linearly loaded dipole?

No, it is a loaded dipole. It uses inductive loading
and top hat capacitive loading. "Linear", in this
context, means "evenly distributed" loading.

Would you keep the wooden dowel form (for the coils), or would you let
them be air-coils (how to keep them from separating [tape])? What
lengths would you use for the wire/coils? What type feed line would you
use: twin lead or coax?

I would use PVC pipe and run a Dacron "messenger line"
through the center for mechanical support.

For the coils, you will need approximately double the
length of the straight wire. Design the coils so you
can add or subtract turns. Or design the top hats to
be adjustable. Or adjust the length of the straight
wires.

The feedpoint impedance will probably be lower than
50 ohms. For single-band operation, coax will probably
work well with an antenna tuner.
--
73, Cecil http://www.w5dxp.com