Good info about grounding.

[nomadradio]

Over the years I have seen more damage from hits to the electric utility than to antennas. Antenna rotator control boxes are a favorite victim. The operator will know to unplug the radio and amplifier from the wall, but leaves the control box plugged in. A surge on the house wiring is looking for exactly one thing, a good ground. Best ground in the house proves to be the tower. But it's on the other end of the rotator control cable. The path from the wall outlet to the tower goes through the control box. I recommend plugging the whole station into an outlet strip, so you can pull that one plug out of the wall when the station is shut down. That's the only surge suppressor I trust.

If you're lucky only the indicator circuits get hammered in the control box. If you're not lucky the rheostat in the motor unit gets whacked as well. Much more trouble to fix.

73

 

[SuperLid]

I have a friend who lives a few miles away and he had his Shack completely grounded as per the ARRL handbook. His system took a direct hit ruined 2 radios. Basically welded the two coax connectors onto the backs of the radios. Evaporated the antenna that took the hit. There are photos all over the Internet of commercial sites with melted equipment after a direct hit. I guess sometimes you're lucky sometimes you're not. So be my guest and don't disconnect.

ARRL Handbook, is full of errors. The defacto industry standard, is Motorola's R56.

 

[Captain Kilowatt]

I have a friend who lives a few miles away and he had his Shack completely grounded as per the ARRL handbook. His system took a direct hit ruined 2 radios. Basically welded the two coax connectors onto the backs of the radios. Evaporated the antenna that took the hit. There are photos all over the Internet of commercial sites with melted equipment after a direct hit. I guess sometimes you're lucky sometimes you're not. So be my guest and don't disconnect.

The ARRL Handbook is NOT the authority on proper grounding. That would be the NEC. It only takes one ground wire to be wrong for very bad things to happen. You do need to get all your ducksin a row. I have seen several of those commercial sites that were pretty much destroyed. No way in hell they were PROPERLY grounded. One common issue among them was mounting the transmitter chassis directly on the cement floor. That offered a path for lightning to enter via the transmission line and exit thru the floor as well as thru the supposed grounding path. We ALWAYS mounted transmitters on a 2x4 on edge frame to isolate it from the damp concrete floor with a single point ground connection to the chassis. Even all our equipment racks were isolated from the concrete floor and grounded. I watched one of my FM sites get hit FIVE times during an exceptionally bad storm. Total damage was a burned up rectifier bank in the high voltage power supply section even after at least six direct hits. The first hit took it off the air and I watched it get hit another five times. Another incident hit an AM site. We never knew it until I showed up doing a routine inspection and found the RF line current meter in the transmitter blackened and crispy. It fused shorted and things get running like a clock. I had a solid state AM transmitter that would trip off the air for a few seconds and reset and come back on every time it got hit. The transmitter SWR protection circuit saw the lightning strike as a high voltage feedback tripping the SWR overload. Disconnecting is a sure way to prevent damage however if grounding is done PROPERLY disconnecting is not required.

 

[Captain Kilowatt]

My philosophy on lightning is: Why even take a chance? Sure, I could leave everything hooked up and hope that my ground and lightning protection systems will deal with the hit. Or I could do what any smart person would do and disconnect everything; power, antenna, and ground, before the storm reaches me. The lightning protection is there to deal with the possibility of an out-of-the-blue strike, not so I can be lazy and not disconnect before a storm!

No disputing that at all however I keep seeing people say that you cannot in any way protect from a direct strike and that if you do have a direct strike you WILL lose gear. THAT is the part I highly dispute. I have seen it get disproved far too many times. Do I advocate for not disconnecting? Not at all. Do I correct people when they say surviving a direct strike is impossible? Sure do.