I'm going to go way out on a limb here and state my beliefs from experience
and hopefully if I'm wrong, someone will tell us so!
I believe there are two types of noise that need to be separated here.
Corona is one and precipitation static is another.
Corona noise will be picked up by any antenna in the proximity of the
source...usually at the top of the tower.
This manifests itself as a building buzz of static which over a period of
several minutes will build to plus 20 over or more and then all of a sudden
apparently discharge and gradually start up again. When it starts, a noise
blanker can do a pretty good job, but as it gets stronger and more complex,
it totally trashes the reception. I dont believe insulated wire will help
anything.
Precipitation static is caused by individual charged rain drops hitting a
bare element which is insulated above DC ground.
You can often here what sounds like a regular hollow "Pffttt" noise of
these drops hitting a yagi element. The idea is that insulated wire,
non-insulated yagi elements (DC short to the boom and ground), and to a
large extent fullwave loop elemtns (quads, etc.) are fairly immune to this
type of noise.
Unfortunately, my most devastating and most common noise in storms is
coronal.
I use #14 or 12 THHN wire which you can buy fairly cheap at Home Depot,
etc. for elements that wont be stressed very much, such as inverted V's.
For dipoles and other high tensile antenna elements I recommend stranded
copperweld or better yet, insulated copperweld. RF Connection sells a very
nice #13 insulated copperweld that tends to resist kinking and the jacket
is extremely tough like that on Phillystran guy cable. Their web page is
www.therfc.com
73, Ty K3MM
To: no6x@inreach.com, towertalk@contesting.com
cc: (bcc: Tyler G Stewart/BENN/CEC)
Subject: Re: [TowerTalk] Antenna Wire
In a message dated 97-12-30 23:58:25 EST, you write:
<< I like insulated! No scientific reason!
My reasons:
1. Normal house wiring ( as I use) is usually cheaper. For the goofing I
do
no need in spending alot of buck to play with something you seen in a
book.
2. The antennas get to be a little shorter, only by a few percent, but
sometimes that few percent is what it takes to make it fit! Besides thta
look at the wire you save for the next one...(there we go back to the
cheap
thing)
>>
Where's W0UN when you need him?
Is rain and snow static the result of ionized particles discharging against
the antenna or is it just an ionized field passing in close proximitiy to
the
antenna? I've heard both theories offered. If the truth is the later, then
insulated wire will not make any difference.
You must take the velocity factor of the insulation into consideration. I
once
built a huge 10 meter Sterba Curtain from insulated wire. It resonated at
27
Mhz.
Indoor insulated wire will stretch and the jacket will deterioriate in the
sunlight and elements.
Choose wisely!
Looking forward to a great '98!!!!
Tom, K5RC/7
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