Hi Ed,
I would make the antenna self resonant at 1.9mhz then
adjust it using a hairpin coil across the feed point. You
only really need to use two loading wires and I use
Stainless steel about 2mm Diameter. I got eyes swaged at the
mast ends and they just bolt to a U bolt. This will take any
Wx that is thrown at it. I think 14 AWG CU will break at
some time. My SS has not yet in 10 years. Eznec says try
about 39ft per side loading with the ends at about 60ft. the
raising and lowering of the ends should give you adjustment
on Frequency as well as the hairpin. 73 Clive GM3POI
----- Original Message -----
From: "Ed Stallman" <n5dg@airmail.net>
To: <towertalk@contesting.com>; <topband@contesting.com>
Sent: Saturday, August 29, 2009 9:32 PM
Subject: Topband: Antenna Modeling needed 160 vertical
> Hello Towertalkers
>
> My plan is to construct a 160m vertical using 4 inch
> irrigation
> tubing 90 ft tall, with 4 top loading wires spaced 90
> degree and
> sloping down at 45 degrees . My target freq is 1.830 but
> would like
> to make the top-loading a bit short so that the antenna
> was resonant
> about 2 MHz. Then put a small (a few uH) loading coil at
> the base to
> bring the antenna to resonance at the desired frequency.
> I am
> placing the antenna 300ft away from any other structure ,
> hoping for
> no interaction . I'll start with 32 ground radials and add
> more
> later, not sure on the length ? 90ft or 130ft ?
>
> two questions
> how long will the top-loading wires be for resonant at
> about 2 MHz
> using # 14 copper insulated wire?
> how long should I make the ground radials ?
>
> Thanks Ed N5DG
>
> _______________________________________________
> Topband mailing list
> Topband@contesting.com
> http://lists.contesting.com/mailman/listinfo/topband
_______________________________________________
Topband mailing list
Topband@contesting.com
http://lists.contesting.com/mailman/listinfo/topband
|