Ladder Line Surge Suppressor

I usually get static build up on my HF doublet due to sand particles (I live above the beach) in the air so have been thinking about a way to bleed off the static and provide some protection to my TS-590SG. After a little research, I came up with this, a lightning arrestor/static bleed device that provides a permanent path to earth for DC whilst allowing RF to pass and providing protection from nearby lightning strikes.

Here’s the parts list:

150 x 110 x 80 box
2 x 100mm M6 304 stainless bolts
3 x 45mm M6 304 stainless bolts
5 x M6 304 stainless locknuts
20 x M6 304 stainless nuts
15 x M6 304 stainless washers
5 x 6.4mm ring terminal
2 x 0.1uF 6KV Capacitor (Mouser PN 75-564R60GAS10)
2 x 2W 1MOhm Resistor (Mouser PN 660-HPC2C105K)
2 x 2700V GAs Discharge Tube (Mouser PN 652-2095-270-BLF)

I spaced the connections to match my 3″ ladder line feeder.

Assembled the bolts ready to install.

The bolts are installed with 2 at the top foe the feed to the antenna, 2 at the bottom for the feed to the ATU (protected side) and one in the middle at the bottom for the connection to earth. I put a little silicone around the bolts to help with weatherproofing.

The resistors installed. These allow DC to pass and bleed any static buildup to earth.

The Gas Discharge Tubes went in next. These are basically spark gaps inside a gas filled tube so they spark at 2700v. The theory is that any nearby lightning strike that generates enough voltage on the antenna will be able to short to earth and bypass the resistors.

Last to go in are the capacitors. These allow RF to pass but block DC from flowing down to the ATU and onto the radio.

I selected an enclosure with a clear lid so I could easily check on the components to see any signs of damage after a storm. Note the small white bag inside the unit. This is a descant pack made from a home “moisture trap” refill and a coffee filter to help help the air inside the enclosure dry.

The next job will be to cut down the bolts (they were the only lengths I could get) and then to install in into my antenna system.

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