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Re: [TowerTalk] Recommended Coaxial Surge Protector for HF

To: "Bill Jackson" <k9rz@radiks.net>, <towertalk@contesting.com>
Subject: Re: [TowerTalk] Recommended Coaxial Surge Protector for HF
From: "Jim W7RY" <w7ry@inbox.com>
Reply-to: Jim W7RY <w7ry@inbox.com>
Date: Fri, 31 Dec 2010 14:44:54 -0800
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
Here are just 3 sites from a simple Google search on "single point 
grounding"

http://www.astrosurf.com/luxorion/qsl-lightning-protection3.htm

http://www.w8ji.com/ground_systems.htm

http://www.k1ttt.net/technote/onepoint.html

Non DC grounded antennas (those without a trifiler wound balun or system NOT 
measuring 0 ohms with an ohm meter across the coax) should always have a 
high impedance choke or resistor to discharge static!  A Polyphaser will NOT 
normally dissipate static unless it has a DC ground path inside.

73
Jim W7RY


--------------------------------------------------
From: "Bill Jackson" <k9rz@radiks.net>
Sent: Friday, December 31, 2010 12:48 PM
To: <towertalk@contesting.com>
Subject: [TowerTalk] Recommended Coaxial Surge Protector for HF

> Happy New Year!
>
> I have a question for the Group about the various brands of coaxial 
> lightning
> protection.
>
> Without going into a lot of detail, I have a SPG copper buss bar in the
> basement that serves as my coax and control cable entrance panel.  Each 
> coax
> and control cable has an appropriate Polyphaser protector mounted to the 
> panel.
> For my HF antennas, I currently have a Polyphaser IS-50UX-C0 protecting 
> the
> single run of 1/2" Heliax out to the tower where I have a remote antenna 
> switch
> installed.
>
> This morning during a heavy snow and sleet squall, I walked into the shack 
> to
> the sound of "tick, tick, tick" coming from the Drake LP-1000 low pass 
> filter
> connected to the coax line running to the SPG in the basement.  As soon as 
> I
> turned the antenna switch to the "off" position, which grounds the 
> feedlines
> feeding the remote antenna switch on the tower, the "tick, tick, tick" 
> noise
> stopped.  This is the first time in the 15 years the antennas have been
> installed that I have ever heard a static discharge inside the shack.
>
> My first assumption is that the Polyphaser surge protector on the coax 
> cable
> feeding the coax switch has lost it ability to shunt a high voltage 
> build-up on
> the center conductor to ground.  However, I have not seen any other 
> symptoms
> such as high SWR indicating the protector may have gone bad.  I do not 
> have a
> schematic of the protector, but I assume there is some type of gas 
> discharge
> device from the center conductor to ground?  Short of having a Hi-Pot 
> tester,
> is there any other way to verify the protector is still working as 
> intended?
>
> Reading some of the reviews on eHam.net would suggest there have been 
> quality
> control issues with Polyphaser since the company merged with Transtector. 
> Has
> anyone performed any evaluation or testing of the various brands of 
> coaxial
> surge protectors, such as ICE or Alpha Delta that would recommend a 
> replacement
> for the Polyphaser?  The current price of a IS-50UX-C0 is about $60.  I do 
> not
> want to spend good money on a protector that is questionable or is going 
> to
> fail prematurely under QRO operating conditions.
>
> Thanks and 73
>
> de Bill, K9RZ
>
> _______________________________________________
>
>
>
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