> -----Original Message-----
> From: towertalk-bounces@contesting.com [mailto:towertalk-
> bounces@contesting.com] On Behalf Of K4SAV
> Sent: Wednesday, September 27, 2006 12:19 PM
> To: towertalk@contesting.com
> Subject: Re: [TowerTalk] homebrew low voltage surge suppressors?
>
> ersmar@comcast.net wrote:
>
> >Dick:
> >
> > I found a few white papers on how the Polyphaser, ICE and Delta
> lightning supressors work and posted about it:
> http://lists.contesting.com/archives//html/Towertalk/2006-03/msg00548.html
> . Enjoy.
> >
> >
> >73 de
> >Gene Smar AD3F
> >
> >
> >
> ----------------------------
> Those ICE articles on how their units work seem to have some
> misinformation. When lambasting the competition they make this statement:
>
> "The use of a gas discharge unit as a sole-source mechanism for
> neutralizing lightning currents delivered by heavy coaxial line
> conductors is controversial. Gas units have only a small dissipative
> power rating, seldom exceeding 1 watt. While the devices can handle
> large jolts of thousands of amperes of current, they can perform that
> service only if the entire impact event lasts only a few microseconds.
> Lightning currents, especially slowed down by time constants due to the
> inductance of transmission lines are much slower to begin, endure, and
> end. The result is rupture and failure of gas discharge units, requiring
> frequent replacement and down time."
>
> On the Polyphaser site, looking up the IS-B50HN-CO suppressor that is
> popular, and going to product specifications
> http://www.polyphaser.com/datasheets/IS-B50HN-C0.pdf
> we see that the current rating is for 50,000 amps for the typical
> lightning waveform, 8/20 microseconds.
>
> There are other examples of similar nonsense in this same ICE article. I
> also find this same type stuff in other articles they have written. I
> would say that ICE needs to clean up their act.
>
> Jerry, K4SAV
I agree with you Jerry. What they fail to disclose is the amount of energy
that is being dealt with. If the "propagation slows down via the coax" that
doesn't change the amount of energy that has to be dissipated.
Their use of a coil across the line is also questionable. The reason that
Polyphaser puts a capacitor in series on the equipment side is so that any
coils in the equipment, like receiver links, doesn't short the line and hold
the voltage low so the gas tube doesn't fire early. Having a DC path to
ground there can allow a significant amount of energy to pass before the
voltage can get high enough for the gas tube to fire. The coil will ring and
pass energy.
On another note on knowing if the gas tube has failed it can be checked
easily with a small hi-pot tester on the polyphaser unit connected to the
antenna side of the suppressor. With a coil to ground in the unit
disassembly would be required to check it.
73
Gary K4FMX
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