Polyphasers

fireboy · #1 (**permalink**) 04-25-2006, 02:38 PM

I was just wondering, how many strikes is a polyphaser good for? and how can you tell if one has popped or not?

EDACS_Tech · #2 (**permalink**) 04-25-2006, 07:35 PM

They're typically good for many, many, many strikes. A system I worked on has been using the same PolyPhasers in VERY lightning-prone areas for almost 8 years. You will start seeing higher reflected power if a PolyPhaser has gone bad. Unfortunately, a bad PolyPhaser is not the only thing that can cause reflected power...and I recall that most of the very basic models are a DC short (except for units to use with RX antennas that have tower top amplifiers, then they use a different model that has DC continuity). Maybe someone else has a better way to test.

gcgrotz · #3 (**permalink**) 04-28-2006, 08:45 AM

Polyphaser used to make a tester. It had (or still has?) a coax connector that screwed on to the unit and then applied a high voltage to test the rated breakdown. We had one when I worked in paging. Check their catalog or web site.

The 1/4 wave shorted stubs work great at V/UHF and 800 but I've seen them do some squirrelly things at 1.9 Ghz pcs freqs. 1/2 wave reflections of impedance bumps on the line is my guess.

Ray-D-O · #4 (**permalink**) 05-02-2006, 09:24 PM

I heard the FAA techs used to wrap wires around cables to ground system then solder free ends to old fashion big camera flash bulbs. If you take a hit then the bulb should flash. I put one in at work. Still has not flashed and I hope it doesn't.

gcgrotz · #5 (**permalink**) 08-16-2006, 08:48 AM

We used to have a tower mounted strike counter by Polyphaser. For years it sat on 0000. Then one time we had a known lightning hit (it vaporized the inside of a fiberglass antenna) and sure enough the counter said 0001. Note also that with extensive grounding and protection on the lines there was no damage to any equipment inside. The antenna was for a monitor receiver and we only discovered it when the tech couldn't hear any of the remote transmitter sites and thought the system was down. We had a Diamond D130 discone as backup on the same tower, it was undamaged and pressed into service.

I'll have to remember that flashbulb trick. Can you still get them?