According to McMaster Carr's website -> The color is opaque white, also
it's a poor electrical insulator and it's for indoor or outdoor use.
To: K1TTT <K1TTT@ARRL.NET>
Subject: Re: [TowerTalk] Insulators
From: "Roger (K8RI)" <K8RI-on-TowerTalk@tm.net>
Date: Sat, 10 Oct 2009 13:59:45 -0400
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
It came up black on mine...<:-))
At-any-rate, Regular fiberglass has variable characteristics depending
on the epoxy and density of the fiberglass/resin mix, how the fiberglass
was handled prior to adding the epoxy (its very sensitive to moisture),
but in the long run at amateur power levels and several times beyond up
through VHF they are far more than adequate. With colored fiberglass
the pigment is sometimes a concern as most constructed with electronic
specs in mind.
Under normal circumstances the fiberglass is probably a better insulator
than ceramic, BUT without proper protection fiberglass deteriorates. The
power industry uses fiberglass cross over support arms and the following
link talks about the short comings when a good protective coating is not
used and they are running far more voltage than we normally do, but at a
much lower frequency.
http://tdworld.com/overhead_distribution/power_flashover_characteristics_fiberglass/
watch out for line wrap in some readers.
73
Roger (K8RI)
>
> David Robbins K1TTT
> e-mail: mailto:k1ttt@arrl.net
> web: http://www.k1ttt.net
> AR-Cluster node: 145.69MHz or telnet://dxc.k1ttt.net
>
>>
>>> Just remember, you get what you pay for... and if a material isn't
>>>
>> designed
>>
>>> for a specific job then it may not do a very good job at it. in my
>>> experience electric fence post material degrades pretty quickly in the
>>> sun/rain, after only a year or two the whole surface is nothing but
>>>
>> loose
>>
>>> fibers. So if nothing else you might want to consider some uv
>>>
>> protective
>>
>>> paint on it.
>>>
>>> By comparison, this material is a bit more expensive ($39.54/5'), but
>>>
>> comes
>>
>>> with known size tolerance, tensile strength specs, and statements about
>>> environmental performance. http://www.mcmaster.com/#8543k11/=3zm45w
>>> And could probably be on your doorstep Monday or Tuesday.
>>>
>>>
>> But what are it's electrical characteristics and particularly at RF,
>> particularly as it's black?
>>
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