Topband: Hardening the 8 Circle Receiving Array

[Lee STRAHAN]

   Hi Folks,
    The Hi-Z Antennas brand amps already have a path to drain static as they are designed to produce 4 to 5  Volts DC on the element with an internal voltage divider. Attaching another resistor would degrade the performance.
Not only does this protect from static but it is a great first step diagnostic tool when checking the health of the system. The YCCC systems are capacitively coupled and could benefit from a 1 Megohm resistor across their amp terminals to drain static. There have been quite a few recent reports of this input capacitor's failure. Albeit no one has determined the exact cause of the failure yet to my knowledge.

Lee   K7TJR
Hi-Z Antennas




Hello Mark!

I have the YCCC Hi-Z spaced at the compromised 60 ft. parameters to improve
80 & 40m operation - that was a mistake!  
Go with the recommended 160m spacing.  I plan to modify my Hi-Z for optimum 160m operation ASAP.

Since the Hi-Z sits on the ground, putting it out in the fall and bringing it back in every spring is not a big deal.  It only takes a couple of hours.
Lightning protection is not usually an issue in the colder months, although we do get "Thunder-Snow" occasionally, but so far no damage from that.

For static build-up protection, which is a real problem in the winter months, I installed 100K 1w carbon resistors bridging the inputs to ground.

This will be the 4th or 5th year for my Hi-Z array.  I also have BOGs and two types of RX loop antennas.  

Lloyd - N9LB


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




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


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