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
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