antenna lightning ground and static bleeding

[cornman]

Hey guys just wanted to share some troubles iv run into.

So very quick run down of my setup, i took the advice i got from a earlier post and got a random wire antenna of about 100+ 18 gauge wire now fed with roughly 100ft run of coax (thats buried underground) with choke inline that runs to my airspy hf+ discovery inside the house. Performance is really good, but a couple of safety concerns have come to mind that jeopardize the entire thing.

What i'm worrying about is antenna static build up and lighting strikes. I hear all thats needed (for static dissipation) is a high voltage rated 1 mega ohm resistor shorted across coax shield and center... but i supose it all needs to go somewhere...like..ground? thats my other problem...i cant do that right now...

I really cant shell out the time and money to acquire and install the heavy gauge wire and copper ground rods needed to create a proper code correct ground that's bonded with the house ground. My homes ground rod is at the other end of the house and will not be trivial for me to reach. So... am i basically screwed? do i have no way of safely dissipating the static buildup and protecting my home from lightning strikes near my antenna? If i disconnect my sdr and antenna before a storm will that be sufficient or is a code correct ground really a 100% must. If i place a ground rod near the antenna and ground it there will that just make things worse? I don't want to accidentally burn my house down and destroy my equipment just because i want my SWL hobby.

 

[krokus]

Do you have the long wire connected to a balun? If so, ground the other side of the coil that the wire is attached to. That will handle static bleed off. Lightning protection takes more, but you will have to decide your balance point of cost versus risk.

 

[RichardW9RAC]

As an addendum for other types of outside antennas that use coax, take a look at Polyphasers. They bleed off static to ground without the build up as Alpha Delta. Your coax ground shield needs to be grounded outside and the mastpipe or other supporting structure also. This may also alleviate noise build up on the wire antenna. High noise levels may benefit with common noise chokes at both ends of coax as in at antenna and at entrance of shack. 73 Rich

 

[prcguy]

A 9:1 balun would be the best advice both for broad band impedance matching and static bleed off. Its probably impossible to protect the equipment from a direct lightning hit but a Polyphaser would mitigate a close strike and resulting high voltage event from the antenna to radio equipment.

 

[RichardW9RAC]

My homes ground rod is at the other end of the house and will not be trivial for me to reach.

As a side note, for when you may decided to bond those grounds together remember also a 20 foot spread between the electrodes is the maximum distance, 8 foot minimum, using 6 copper wire or heavier. 73 Rich