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Static danger

I had to terminate my activation of GW/MW-025 very quickly this afternoon because of dangerous static build-up on the antenna. The first indications were a crackling noise in the receiver, similar to car ignition noise, slowly building up in strength and pulse speed until it was almost a high-pitched whine.

Then I started to get electric shocks from the Palm Key casing and the metal case of the rig. Concerned that the receiver might suffer damage, I unplugged the antenna from the rig … receiving several sharp shocks in doing so! When the coax downlead was disconnected, I was somewhat alarmed to see (and hear) a blue spark jumping between the centre pin and the shield of the PL259 plug every couple of seconds.

I was quite surprised that the short antenna I was using at the time (a half-wave wire dipole for 28 MHz at 7m height) was able to pick up enough potential to produce sparks across the plug. Interesting too that it was not raining at the time, no lightning was visible, but thunder could be heard in the distance. I packed up swiftly and headed for the safety of the car at the foot of the hill!

It certainly served as a timely reminder that one needs to exercise extreme caution when operating from an exposed hill-top in thundery weather.

73,
Walt (GW3NYY/P)

In reply to G3NYY:

I have experienced something similar a couple of weeks ago while activating SP/BZ-001 - a high and exposed summit. I had no wire antenna up in the air, just a half wave telescoping whip on my 2 m FM handheld. Thunderstorm was near and I got a nasty spark from the case of the transceiver into my finger. Fortunately, I had already four QSOs under my belt but I would definitely retreat quickly even if I had not. I was surprised the radio suffered no damage.

73,Ruda OK2QA

In reply to G3NYY:

Very wise Walt, apart from the risk of damage to your equipment the risk of damage to yourself is very real. I had to disconnect my 160m dipole on Fair Snape fell last month due to static build up, despite no thunder storms being forecast in the area.

The only other time I have disconnected in a hurry was on Pendle Hill during a 144MHz backpackers contest when I was inside a tent. I didn’t see cloud arriving but I certainly heard it discharging through the radio.

It looks like 10m has been in good shape today along with 6m, 4m & 2m although 2m appears to have closed here now.

Hopefully there will be some good eS tomorrow to give any upper HF or VHF activators the chance of some unusual contacts.

Best 73,

Mark G0VOF

In reply to G3NYY:

Rather surprised that you stuck it that long Walt. I always disconnect immediately it starts crackling. Even so I managed to get a shock on the last outing and saw several sparks to ground once I’d laid the connector down… and my antenna was only a 2m dipole at less than 3m above ground.

A few years back, Richard G3CWI shot a video, on G/TW-004 if I recall correctly, which shows fairly hefty sparks across the RF connector.

73, Gerald G4OIG

Heres the link to Richards video