In my youth,I was told not to solder wire antenna ends. The reason: copper
contains some amount of SiO2, which crystalise under the heat and copper
become fragile (breakable) at soldered points. In my 40 years of ham radio,
I actually have seen lot of wire antennas broken right next to soldered
point.
73, Mirko,S57AD
-----Original Message-----
From: towertalk-bounces@contesting.com
[mailto:towertalk-bounces@contesting.com] On Behalf Of David Robbins K1TTT
Sent: Sunday, July 02, 2006 1:11 AM
To: 'TowerTalk Reflector'
Subject: Re: [TowerTalk] Ends of Dipoles - Mythbusting
Lets apply what is in your signature... some common sense. Compare the size
of a 1/2 wave dipole, say even on 10m with the size of the loop and a few
turns of wire. Such a small loop may add a very tiny bit of capacitance to
the end of the wire, and the inductance of the tiny coil is negligible.
Take it down to lower frequencies and the effect just gets smaller and
smaller.
Personally I just form a small loop by folding this 10ga insulated
Copperweld I use back on itself and secure with either tape or a cable clamp
and just tie it off with Dacron rope. Works fine, lasts a long time, even
in New England icy winters. If you have any worry about what the insulation
or tiny loop on the wire does to the resonant frequency just do like I do,
cut the wire way long, put it in place with the approximate droop and height
it will finally end up at, measure the resonant frequency, and compute how
much to cut off from that. This compensates for not only the tiny effects
of the end of the wire, but what are usually much larger effects of trees,
towers, houses, and other antennas in the near field.
David Robbins K1TTT
e-mail: mailto:k1ttt@arrl.net
web: http://www.k1ttt.net
AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
> -----Original Message-----
> From: towertalk-bounces@contesting.com [mailto:towertalk-
> bounces@contesting.com] On Behalf Of Lee Buller
> Sent: Saturday, July 01, 2006 22:58
> To: TowerTalk Reflector
> Subject: [TowerTalk] Ends of Dipoles - Mythbusting
>
>
>
> Mythbusting......
>
> Statement - you need to solder the ends of the dipoles because the loop
> in the end insulator and the wrapping of the wire back onto the antenna is
> a inductor and a capacitor...thus changing the resolate frequency of the
> dipole.
>
> True or False
>
> Myth or not
>
> Lee - K0WA
>
>
>
> In our day and age it seems that Common Sense is in short supply. If you
> don't have any Common Sense - get some and use it. If you can't find any
> common sense, ask for help from somebody who has some common sense.
> _______________________________________________
>
>
>
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> TowerTalk@contesting.com
> http://lists.contesting.com/mailman/listinfo/towertalk
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