During activation #3 (GW/NW-051) of four around the Clwydian Range and Dee Valley in North-East Wales on 14.03.26 (Sat), I received electric shocks during a hail storm whilst operating on 2m FM with my handheld and rollup Slim Jim.
I had never experienced this before, and at the time I thought it was perhaps the result of equipment failure, a short in the antenna for instance, but am now more convinced it could have been a build-up of static electricity.
I had used the same setup during activation #1 (GW/NW-042) and #2 (GW/NW-042) earlier that day (and done so many time before - even in the rain - without any issue); handheld, rollup Slim Jim mounted on a 4.1m fibreglass pole which was tucked into my backpack placed in front of me whilst sat on a sit mat on a stone.
When the hail stones came down, it did not last long but a lot fell in a short period of time and they were quite painful upon landing despite being relatively small.
I first noticed some small pulsating shocks - similar to that of an electric fence (which was not there) as I was mid-QSO; then quickly it became more intolerable so dropped the handheld. Each time I tried to pick it up, I got a shock upon touching it (anywhere), without transmitting. Touching the antenna coax and connector all gave the same unpleasant result. I swapped the Handheld for my spare and that gave the same result, so I lowered the mast and packed up.
As I entered the Activation Zone of the final summit of the day, the weather changed and it started to rain.
Not knowing whether hail would follow, I did not use the antenna, but instead a telescopic whip for a quick activation.
I will perform some tests on the antenna in the coming week to see if there are any obvious issues.
Has anyone experienced something like this before?
What is the likelihood that the shocks were caused by static discharge as a result of the hail instead of it being equipment failure?
Multiple times… rain, hail and even in snow. I’ve even seen sparks jump from my coax to ground and to my hand. I got a really nasty one when I held the rig with one hand and disconnected the BNC connector with the other. I then learnt to just use one hand to unplug the coax.
A hailstorm can cause an electric shock because the hail (ice particles) and strong winds create a high-voltage electrostatic charge that builds up on the radio’s antenna.
Even in dry conditions ES charge builds up on kite-borne EFHWs due to the friction between the long wire and the air. In that case the bleed resistor leaks the charge continuously and harmlessly to ground.
But with a VHF handheld the charge builds up until large enough to discharge through that big watery bag we call the activator.
I have had a shock from static on a day when there was a strong southerly carrying dust from north Africa. I happened to touch the case of my 891 and got a fair nip.
Although one could in principle run a bleed resistor from the HT’s antenna via a wire to ground (like with kite antennas), for the safety of the operator and the radio electronics the best thing is to stop using the radio in a hailstorm or heavy snowfall, and de-erect any external antenna on a pole.
The strongest static discharges I’ve ever seen happened when we put a kite antenna up on the island of Juist. The kite wire being about 120m long had to be grounded with a lightning protection rod. I do not remember how the trx was protected. I found this: How We Flew An End-Fed Half Wave (EFHW) Ham Radio Antenna On A Kite (VIDEO) – KM1NDY and this: Drachenantenne DD7LP M04 (in German). The static was caused by the wind only, no thunderstorms about.
Judging by the cloud in the cairn picture, you could well have been on the front edge of a long trailing cold front coming in off the Atlantic. The sharp cloud boundary and the hail/graupel on the ground are classic indicators of unstable air in a passing front, especially if it was relatively mild at ground level.
If there was active convection, electrostatic buildup would certainly be possible on high ground - If so, it probably wasn’t the best moment to have antennas up and operating!
I was operating in Alaska using a long wire antenna once near sea level when something in my antenna tuner started arcing over at regular intervals. There was no precipitation at the time, but a strong wind. I grounded the tuner using a scrap of wire and a metal skewer (the ground outside was always damp) and the problem went away. This was in an area where it rained a lot, but lightning was very rare.
Static build-up due to wind is a particular problem with helicopters: when they are carrying a sling load underneath, you always let it touch the ground and discharge before you try to disconnect it.
It’s a significant, well-recognized problem for designers of all forms of aircraft. It happens when an aircraft flies through precipitation (rain, snow, ice crystals, or dust), causing particles to collide with and rub against the airframe, creating static electricity.
Even in dry, dust-free conditions, you get ES charge build-up with kite-borne HF antennas. This is known as triboelectric charging (due to the loss of electrons between the metal wire and the surrounding air molecules). Don’t think using plastic-coated (insulated) antenna wire helps. In fact, using insulated wire often exacerbates the problem.
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Having sat on a summit through a hailstorm that turned to a decent snow shower recently I was going to ask the more experienced peeps on here if it was possible to detect static or impending lightening through listening to their radio? I’m aware you can hear distant lightening on hf as pops and cracks of course, but is there any other indication?
