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 _________________ Searchable Archives: http://www.contesting.com/_topband - Topband Reflector