How many of you spent the time to install one of these ?

Gents and Ladies or course,

just wondering how many of you have spent your hard earned cash on a nice radio, worked hard to put that new shiny antenna thats going to drag in the DX day and night and forgot ONE very important cheap device !

https://www.dxengineering.com/parts/dmn-sp1000

??

Ady

I unplug every day after i close the station down.
73,
Mark.

Same here as Mark does, simply unplug.  

https://sz1a.org/en/featured-articles/lightning-protection-of-an-amateur-radio-station/

As someone who was involved professionally in lightning and electrical surge protection for radio installations for many years, I can wholeheartedly endorse the “unplug your coax” idea. I would go one stage further and say that if possible, disconnect the antenna OUTSIDE the shack rather than just disconnecting it from the rig. Remember - the lightning has already jumped several hundred miles from the cloud to your antenna, so it certainly isn’t going to be put off jumping another couple of feet from the coax connector to the rig!

Also, that article by SZ1A is very good, and well worth reading.

Regards,
Keith G0RQQ

Remember - the lightning has already jumped several hundred miles from the cloud to your antenna, so it certainly isn’t going to be put off jumping another couple of feet from the coax connector to the rig! Keith G0RQQ

Totally agree with you on this advice Keith, i always play safe and disconnect everything here as we live in a region that is high risk, i have surge devices on the house mains, a substancial earthing system and on each coax i have good quality surge protectors, even on my ladderline doublet, i have a good photo of a strike that hit behind our house a few years ago on an industrial plant the other side of the river from us, apart from the fact i filled my pants taking the photo on the balcony, i was amazed the two cats we had a the time who did nothing all day, when motivated could literally break the sound barrier running in the opposite direction into the house !!!

I notice you live in Lincoln, know the place well, used to work just down the road from you on the A15 on the left hand side with the little antennas on the old airfield !!

Regards Ady

Ah - I know where you mean!! :-)

In his article, SZ1A mentions the need for good grounding/earthing on metallic structures and ensuring a good earth in the concrete base of a tower. At one company for whom I worked, we had a test structure known as “Big Bertha” for reproducing the effects of a lightning strike. It consisted of a horizontal conductor, made from a lattice tower, and a test-bed connected to a room full of enormous electrolytic capacitors. These capacitors took roughly a day to charge up! The device under test was secured to the test-bed , the tower section was positioned above it, everyone retreated to an observation room and put on ear defenders, and the capacitors were discharged through the device under test. The resultant bang was quite impressive! I can’t recall what the voltage and current capabilities of “Big Bertha” were, but they were capable of vaporising some items.

One time, some construction people had been at the plant to move the test set to a new building. I guess they didn’t realise the need for really good earthing for Bertha. The first time it was fired up there was a lot more flashes and smoke than normal; when it had cleared, there were some quite large holes in the concrete floor around the earth rods!

Regards,
Keith

Keith, i know you know what you talking about, on every site i have ever worked, Military or not Earthing is the key to protection, this was the simple reason i started this thread to make CT members realise that the chances of damage from lightning are low and there is no real risk is false.

When i was stationed in Berlin we had two main sites, one at RAF GATOW and the other on a hill called Teufelsburg (the highest point in Berlin constructed out of the debris of the millions of building destroyed in the war) as you can imagine our antenna systems where the basis for a ham operators wet dreams (money not being a problem), the takeoff on the microwave bands was incredible, however we suffered huge electrical storms, Berlin is literally situated in a climatic corridor where the hot air from the south pushes north in the summer and the cold air from the Baltic sea descends in the winter, thus the huge variations in temperatures in Berlin from winter to summer. When the two combined the storms were something that would have most people ripping PL259's out of the back of rigs in a rush !!
I remember ditching my headphones and stepping away from the racks where the gear was located more than one once, standing on the thick rubber mats we had scared shitless !
The biggest bang from lighting i have heard was on a black GCHQ site in a country overlooking the Black Sea, when we got hit with a huge strike....I went deaf for about a day !!

I can see the Pyrennes mountain range from here and the storms here a very extreme when they cross over into France, i must see if can post the photo i have from the strike behind our house...
Catch you on 11/10m or 40m one evening.....

Regards Ady F5VLY


http://www.lovethesepics.com/2011/08/abandoned-nsa-listening-station-on-devils-mountain-berlin/

I’m familiar with Teufelsberg although I’ve never visited the location. Some interesting work went on there, I believe…. ;-)

Another thing about lightning that people sometimes forget is that you don’t need to have a direct hit to cause damage. A moving electrical field (the lightning discharge) passing a stationary electrical conductor (your antenna or coax) will induce an emf into that conductor. Therefore a nearby lightning strike can cause damage to your radio as easily as a direct hit. Consequently disconnecting the coax as soon as you hear thunder is a good practice.

Lightning protection devices for RF equipment is necessary for commercial installations that need to be on the air 24/7; you can hardly run around disconnecting the coax from all the cell-phone base stations every time there’s a storm! However, for hobby usage the simplest protection method is “disconnect your antenna” - and outdoors if possible.

Yes, maybe we’ll run in to each other on the air some time. I operate mainly QRP and 10m.

Regards,
Keith

How ironic, same modus operandi here Keith.
Have a good evening
Regards Ady

Lightning has a way, if it wants it will.

I have an entry panel, actually a large equipment box mounted on the outside of the shack with Alpha Delta surge protectors on each coax and 25mm lightning strap to a ground rod.

I still disconnect inside as the surge protectors will not stop a direct hit, not perfect but it should stop
nearby hits causing a problem.

We had a real close hit back in August that took out our phones and it blasted a neighbors internet router.

.

It’s worth keeping an eye on the lightningmaps.org website if there’s the possibility of lightning in your area. That way you can judge the likelihood of being affected.

.

Agreed! I looked into getting one too but decided that lightningmaps.org was a much cheaper solution! ;-)

From experience, unplugging didn't help us, I think if you moved your coax feed quite some distance then you would be ok.
I was working on the Sarawak/Indonesian border carrying out survey work. We would fly in to the hill tops and get winched down. The top of the hill was generally cleared of trees for visibility but 2 were left up for a dipole. There was a massive storm one night so the coax was unplugged from our radio. We were huddled in the basher sheltering from the rain. The coax feed entered the basher along the ridge. Hanging from the ridge was a tilley lamp. The lightening decided to pick on us. The lightnings main path to earth seemed to be along the coax which was along the ridge of the basher then through the tilley lamp to earth. The lamp didn't catch fire but the glass was broken. Two of the laborers received burns, the was a hole in the ground below the lamp, the radio headset seemed to turn inside out and the radio never worked again. It was like a stun grenade and we were all dazed for a short time. Luckily we had micro wave measuring equipment which had voice communication. First thing the following morning the 2 laborers were casivaced out  we were given a new radio and carried on. Since then I have always respected the elements, try and remember to unplug but realise if you get it full blast then theres not much you can do. I think the arrestors are good for static.

My radios are not left in the same location as the coax after use