mike_kilroy
Senior Member
- Location
- United States
recent post showing how it came down a tree, thru ground, to house wiring, made me write this.... this week I had opportunity to go up 850 ft to parabola and receiver room of worlds largest high freq radio telescope! Absolutely wonderful tour & nice seeing all my servo motors & drives up there.
But I asked about lightning issues since it HAS to be hit often: they used to have lightning damage all the time - until they put all exposed wiring inside conduit & added rfI filters to all external leads!! They claim no damage for the last few years by these simple changes!!!!
Of course all metal parts are bonded/strapped together, and their path to ground is thru 4pc of 4" round x 5" long brass slugs spring loaded against ss plate that is grounded around base (like 500' dia circle). antenna can hold a full size NFL football field on it....
but I am still in awe that they have stopped lightning damage to VERY sensative electronics on a metal structure 500' higher than any surrounding stuff!
But I asked about lightning issues since it HAS to be hit often: they used to have lightning damage all the time - until they put all exposed wiring inside conduit & added rfI filters to all external leads!! They claim no damage for the last few years by these simple changes!!!!
Of course all metal parts are bonded/strapped together, and their path to ground is thru 4pc of 4" round x 5" long brass slugs spring loaded against ss plate that is grounded around base (like 500' dia circle). antenna can hold a full size NFL football field on it....
but I am still in awe that they have stopped lightning damage to VERY sensative electronics on a metal structure 500' higher than any surrounding stuff!
