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Re: Topband: Hardening the 8 Circle Receiving Array

To: "'Mark Robinson'" <markrob@mindspring.com>, <topband@contesting.com>
Subject: Re: Topband: Hardening the 8 Circle Receiving Array
From: "Lee. KX4TT via Topband" <topband@contesting.com>
Reply-to: "Lee. KX4TT" <kx4tt@yahoo.com>
Date: Fri, 18 Oct 2019 09:16:26 -0400
List-post: <mailto:topband@contesting.com>
GM Mark,
The easiest way to think of this is Diodes = Detectors; with high-powered RF
around, that becomes a Bad Idea. A possible alternative MAY be high-value
resistors to ground across the front end of the preamps. A representative
value would be 10 MΩ or greater, and I would match the resistances to ±1%.
However, Tim's warning still applies in that this mod may damage the
performance of the array. I only mention it because I've used it with kite
and balloon antennas to drain off static discharge, and it may prove useful
here. 

73 de Lee KX4TT


-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Tim Duffy


Hello Mark:

Installing diodes can cause severe problems with nearby broadcast stations.

During the summer months and lightning months I remove my preamps from the
antenna elements to protect them. 
I am now just getting them installed tomorrow morning to prepare for the
Fall Stew contest on Saturday.

Be careful making modifications that may hurt your array performance

73
Tim K3LR

-----Original Message-----
From: Topband [mailto:topband-bounces@contesting.com] On Behalf Of Mark
Robinson

I  have the DX Engineering 8 circle receiving array sized for 80/160m . 
It has been a fantastic performer but I have suffered damage to the active
antenna amplifiers on two separate occasions due to nearby lightning
strikes.

I am looking at a way to protect these amplifiers.  I was wondering if I can
add a pair or  dual series pair (4 diodes in total) of back to back diodes -
say 1N3600,  across the input to ground terminals on each amplifier.  Will
this affect the performance of the array in any way ?

73 Mark N1UK

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