I've had several emails regarding the links below. Apparently they are
no longer accessible from most computers. Although I can open them from
one of my computers, I cannot from another of my own machines.
If anyone wishes, I will be happy to run some figures for anyone who is
interested. Please provide the following information:
1. The frequency for the planned dipole or vertical
2. The desired length of the quarter wave (with the coil)
3. The distance from the feed point you wish to place the coil
4. The gauge of the wire you plan to use to wind the coil
This information will calculate the necessary loading coil inductance.
Also, provide (to design the coil itself):
1. The desired diameter of the coil you want
2. The length of the wound coil.
This will tell how many turns are needed for the coil to get the
inductance.
Finally, give me a little time to run the figures!
73 de N8AU, Jim in Raymore, MO
----- Original Message -----
From: "Reicher, James" <JReicher@hrblock.com>
To: <towertalk@contesting.com>
Sent: Friday, November 11, 2005 6:50 PM
Subject: Re: [TowerTalk] 160M DIPOLE USING COAX
> Hector (et al),
>
> I've successfully reduced the size of my 160M inverted vee to just 100
> feet, using loading coils. Performance appears to be quite adequate,
> although I've taken no measurements other than SWR, due to lack of
> instruments or software. I used 18 gauge magnet wire wrapped around a
> PVC form. The legs of the antenna are just 50 feet long per side, for
a
> total length of 100 feet. I won't claim that its performance is
> optimal, after all, it is a reduced size antenna, but I was able to
tune
> it to a 1.3:1 SWR without the use of a tuner. I've run the ARRL 160M
> Contest with it in the QRP category and had little difficulty being
> heard by any station I worked (I came in second in my division that
> year).
>
> I got assistance in designing the coils from this website:
> http://ecosse.org/jack/radio/software/loading.html
>
> This page will tell you what the loading coil inductance needs to be,
> based on frequency, length of the antenna, the position of the coil,
and
> the diameter or gauge of the wire used to wind the coil. After you've
> determined the inductance, go to this page to design the coil itself:
> http://ecosse.org/jack/radio/software/newcoil3.html
>
>
>
> 73 de N8AU, Jim in Raymore, MO
>
>
_______________________________________________
See: http://www.mscomputer.com for "Self Supporting Towers", "Wireless Weather
Stations", and lot's more. Call Toll Free, 1-800-333-9041 with any questions
and ask for Sherman, W2FLA.
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