/hamradio/ - Electronics

Lightning is really not that much of a danger.

And yeah if lightning hits the antenna the radios and possibly gear close to them/connected to them is also toast.

You can get lightning arrestors for the coax.

I also personally keep all antennas disconnected while not in use.

>>502

what would an arrestor do that keeping the radio unplugged wouldn't? I know arrestors aren't enough to save your radio in case of a strike.

is this good advice? http://www.k3dav.com/antlightningprotectors.htm

>>509

also on a different topic from that article, he says antenna grounding can be successfully accomplished by grounding the coax at the loightning arrestor point. is this true or will it get me fucked?

Unplug your kit. Hope your antenna in grounded. Wait for storm to pass.

>>510

This should not fuck you. The arrestor should have a good low impedance path to ground.

>>505

If the radio is unplugged it might survive a hit to the antenna. With the arrestor it likely won't. But stuff downstream of the rig might. and the rig likely won't catch fire.

The amount of energy in a lighting strike is quite insane. Good protection is hard.

>>512

I meant keeping the radio unplugged from the antenna, not unplugging the power.

>>510

>is this true or will it get me fucked?

as this anon says

>>512

>This should not fuck you.

in fact if your lightning arrestor does not have a good path to ground it is useless or worse by giving you a false sense of security.

>>512

>The amount of energy in a lighting strike is quite insane.

is so true it hurts.

I can tell you what I've seen from my work in cell phone base stations.

1. well grounded arrestor

2. arrestor is placed at lowest point on coax either on tower or building.

3. equipment inside is not connected to power mains grounding system.

#3 can be accomplished like the cell tower does by running all equipment from 48v battery bank that floats on a constant charge system.

or

using a good UPS for your equipment to provide ground isolation.

In short the antenna needs to be well grounded not your radio. You want the ONLY path to ground to be through the arrestor and not your costly equipment inside the shack.

If you just plug your equipment straight into the wall outlet there will exist a low impedance pathway from the transmission line's coax shield thru the chasis of the radio to the power mains grounding system that a lightning strike will follow.

I cannot say it enough times, the only thing in the system that should be well grounded is the antenna, and the shield on the coax.

they go to great lengths to ground the cell tower and shack. there are usually several ground rods driven 20 ~ 30 feet down in a circle. each ground rod is connected to the others via a thick solid copper wire that is welded at all connections. But the only equipment inside the shack that is grounded is the battery charging system transformer's primary winding and the florescent lights, all the radios and other equipment floats on the 48v DC.

for a home radio enthusiast I would recommend a computer UPS (un-interruptible power supply) to power the radio and a good ground rod and lightning arrestor placed close together where the coax enters the house.

I've seen people drive ground rods with hammer drills, it seems to work fairly well.