LIGHTNING STRIKES AGAIN.

Good morning and hi to everyone. My name is John and I am new here. Firstly, perhaps thanks to all for having me aboard and thanks so far for being made so welcome. Right, to topic. Lightning. I have explained on another part of the forum as how we are having to relocate shortly and, in a nutshell, I am having to go vertical. I am at present horizontal using a longwire for HF work. OK, so it is a bungalow and my chosen antenna (thus far in research) is to be a Comet CHA-250BX11. When I factor in height of bungalow eaves apex plus antenna we are looking at some 12 meters up to tip approx. Comet informs myself this antenna needs no grounding nor radials etc. LIGHTNING. What to do? I have enquired with Comet themselves and they simply say unscrew at rig end. Hmmm. I am rather confused as well as rather worried of course. If I ground the antenna it will surely mess up all settings etc. If I ground the antenna mast at apex height and we DO get a direct hit this will be ineffective as the path of least resistance will still be the coax...all I have come up with so far is to fit a lightning arrestor. Perhaps I am worrying unnecessarily? The thing is, once the antenna is up (and I am having to get it fitted by tv aerial technicians for health reasons) it is up. I will not be able to shimmy up ladders in a storm. I would be so grateful for any advice here please. Hoping I have managed to explain the scenario ok. Again, I did speak with Comet America yesterday and also with the antenna erectors and the lack of insight is, frankly, troubling. OK guys, looking forward to any advice and direction possible.

Hi John,

Well, can of worms right there but here goes.....

The lack of apparent 'insight' is not at all surprising because no one seems to be able to state anything with any certainty regards lightning. It's been discussed ad infintum here, elsewhere and probably always will be.
(Even the scientists argue it.)

Some will spend a literal fortune running copper straps, copper rods, etc. etc. still never knowing with any certainty that they are protected only assured with the money they've spent. Others will spend the minimum thinking a big old bit of earthing cable from the local DIY outlet will do the job strapping it to their antenna and a nonchalantly hammered stake in the ground. (Often without regard to UK earthing standards).

There is a theory that such antics actually creates a lightning conductor increasing your chances of a strike, others will state it dissipates static charges from the antenna thus preventing a strike. I personally agree with the latter but would rather ground through 'lightning arrestors' that actually dissipate such static charges than a direct to ground method. 

We did have someone post a video up here somewhere showing the sparks achieved just via static discharges through the end of a PL259 on a mobile setup. (Parked up pretty close to a storm front!! )

For that very reason alone the suggestion you've received of disconnecting the antenna from the radio during a storm is a good one. It's something that's practised by many radio operators too.


But, realistically if you try to find tales of antenna strikes on your average home radio setup you'll find them few and far between. Sure they look spectacular with radios literally burned out with huge scorch marks on the walls behind but you'll see the same images time and again. For the vastness of a worldwide internet you'd expect to find far more images or tales of woe so again shows the scarcity of it occurring.

I honestly wouldn't worry, you've got better odds of winning the lottery than a lightning strike.

(Anyone old enough to remember the big old 'H' antennas we used to have for VHF service Television? Huge things strapped to the top of our houses and not once did I hear a tale of one being hit by lightning blowing up the TV in the middle of 'Corrie'! )


For piece of mind I'd suggest as a minimum of disconnecting the antenna during a storm. If I was going any further I'd place a spark-gap style arrestor from either the mast or the coax shield to dissipate static charges. (Anyone remember St.Elmo's fire? Probably not in this light-polluted world. ) I've seen such devices 'homebrewed' by utilising old spark plugs from petrol engines.

You could of course spend way more money and time than needs be......but if that is the price of your 'reassurance' then who am I to argue.



Hope that helps somewhat John. It's given in the spirit of helping.

All the best,
Victor

Oh Victor, here you are again affording me so much common sense and wisdom. Yet again, you are so right and we have already talked of minefields!!! Years ago and in years of youth, rubber ducks and smokies on tails did I give a stuff? Did any of us regards such issues. Unfortunately, with advancement of years comes so many more doubts and concerns! Should I really be doing this, that and the other? Of course I am doing little other than researching all of this online and am fast coming up with precisely the same conclusions as yourself. I need to step back, breathe, mentally go back to youth a tad and implement common sense garnered over the years. Disconnect obviously, buy some lottery tickets, maintain the faith and carry on regardless. Victor, you come across as a good man, hope you do not mind me saying. Best regards new friend, John.

hi john ,Callum (DX commander) made a YouTube video on his direct lighting hit. Very interesting watch, but long story short ,EMP fried everything electrical, even radios unplugged and in there box. He stated very few amateurs take a direct hit hopes this helps.
regards
mark

Wow, hi there Mark. So very good to hear from you and many thanks for your time. Yes, I watch / have watched so many of his videos...happen not that one. I think I possibly have an age thing going on, plus my so obvious apprehensions about going vertical through necessity. I simply do not want my wife's new bungalow going BANG. Further to Victors earlier post, for sure I remember the early days of tv and the absolutely humungous H antennas upon everyone's house, well, those blessed enough back then!!! 6 inch screen I recall and many a slapped behind!!! Oh how we have moved forward and yet basics still apply. Possibly apply the rather infamous "more chance of being bitten by a dandelion rule"? Regards Mark.

hi john, not a problem and just to confirm I have a gainmaster with base 6m off the ground and also use a efhw (gwhip) which is only 12m long ideal for small gardens. But also unplug in bad weather
regards
mark

John
Just a though (nothing to do with lightening) but have you ever tried a cobweb antenna.
I have just put a 7 bander up last week and so far i am very pleased with it.
Did have a efhw wire and did ok with that but not a patch on the cobweb.
Plus you don't need to have it up very high mine was tuned at 4meters high so i installed it at the same height,

If I may weigh in on this subject…. First, to establish my credentials, although I am now retired I worked in the telecommunications wireless industry focussing for about 15 years of that on lightning and surge protection for the North American, European and Scandinavian markets dealing with the likes of Nokia, Ericsson, Motorola etc. I would work with engineers on designing lightning/surge protection systems and also lecture on the subject.

Lightning protection is a complex subject but to boil it down to its simplest element the advice given to disconnect your antenna is the easiest solution. The use of lightning protection devices is justified if you want to keep operating during a storm, which of course is a necessity for commercial enterprises such as EE, O2 etc. - they can hardly unplug their antennas when there’s lightning about! Having said that, though, a good earthing of the lightning protection device is absolutely paramount - I used to tell the customers that if they’re not going to install a good earth, then take the money they were going to spend on the lightning protector and buy a few beers because it would do them more good!

Remember too that a lightning protection device in your coax does not prevent lightning hitting your antenna - what it does do is provide a lower-impedance path to earth for the lightning energy instead of it passing through your radio. If you rely on disconnecting the coax during a storm, then it’s better to do so outside your house. Having the end of the coax inside the house could still result in the lightning energy travelling down the coax to the connector and then jumping across to a “convenient “ point to earth. Having jumped several hundred or thousand miles from a cloud to your antenna, it isn’t going to be put off jumping another few feet to your radio!

Good morning gentlemen and, of course, any ladies present. Well, thank you all so much I have to say. Alan, I cannot be sure and yet feel that there is no way I would get away with putting up a cobweb antenna. We live in a very small and compact village and the part we are relocating to (it is actually my wife's Mum and Dad's house who have sadly only just passed) is very tight knit in every sense of the word. They are certainly very good antenna however. G0RQQ, thank you so much for your well founded and expert advice which I am absolutely taking onboard. I shall therefore be asking the aerial erect chappie to be running the coax down the wall instead of straight into the house under the eaves and installing a female to female link which I will be easily able to disconnect / reconnect etc. It is the only safe and practical way I can think of following your advice. I really am so grateful for all your help guys.

I found some of my old notes on lightning and lightning protection so here’s some food for thought:
- Lightning kills 50 people per annum on average in the USA.
- There are roughly 200 storms on Earth at any one time
- Lightning strikes the Earth on average 100 times per second every day
- The average current of lightning is 20,000 amps but can peak at 300,000 amps
- The average voltage is 200,000,000 volts but can peak at 300,000,000 volts
- Therefore the peak power could be as high as 6000 Gigawatts, but that lasts only millionths of a second.
- The temperature of the lightning bolt is roughly 30,000 degrees C, or 5 times hotter than the surface of the Sun.
- The average lightning bolt length is 16kms but can be as long as 40kms.
- Earthing for lightning protection is best accomplished by using a flat copper strap for ease of bending and attachment, and not a wire. The charge current is conducted by skin effect so surface area is more important than diameter. For example, a flat copper strap 8cms wide has 16cms surface (8 on the top, 8 on the bottom). I’ll leave you to do the maths on the size of a wire with 16cms circumference!

Good morning to you G0RQQ. Oh my goodness, you have left me suicidal. Only funning. Wow, those statistics are totally mindblowing, well, for someone with a mind like mine. G0RQQ (forgive me as I do not know your name), do you think my idea of having a disconnect outside on the wall will suffice? Obviously so long as I keep the "into house" and disconnected end of the coax well away therefore. PLUS, obviously a disconnect at the shack end as routine also?

Oh - sorry….my name is Keith.

Yes, it should be OK. One thing to remember is that the incidence of lightning in the U.K. is far lower than some other countries such as the USA, central Germany, Africa etc. Also, you are far more likely to suffer damage as a result of a “near miss” than there is likelihood of a direct hit. This is because energy can be coupled into your antenna by lightning hitting something close by, and that energy can damage or destroy sensitive electronic circuitry such as your radio.

The other thing is that the possibility of being hit by lightning is to some degree a game of chance. Lightning will not necessarily always hit the highest object. I have seen instances where lightning has missed a tree but hit a bush at the bottom, or missed a large house but hit a garden shed. Yesterday I saw a video from this last weekend where a teenager in Texas was hitting some golf balls on a golf driving range (NOT a good idea to play golf in a thunderstorm!). As he hit a ball, lightning struck the ball in mid-flight!

Keith, I am so grateful to you for taking the time to...forgive me here...enlighten myself and I dare bet one or two others also. You have been most informative and I have absolutely paid heed to your words of wisdom and knowledge.

You’re very welcome!

Icelandjon Just a tip.
John if you click on the user name in the box to the left of a post it will take you to the user profile and at the top is there name.

Straightforward earth to the mounting brackets is what I have used in the past, 2m of copper pipe hammered into the ground with a hole drilled at the top to attach heavy earthing cable was more than adequate and I had a Sigma 4 (Vector 4000) on top of three lengths of scaffolding with an array of guy wires to keep it more stable.  In the event of a storm nearby I would tend to unplug the coax from the radio as a matter of course and still do.  
I looked at this antenna myself but was a little put off by some of the reviews comparing it to a silver rod with 6 to 1 Unun, I did however find people who had stuck with it made a modification or two and report to be doing very well indeed with it.  This chap, Martin G8JNJ has put together a handy PDF about his modifications and the results he got which seem good and I will leave a link as it struck me as a good resource I hope you find it helpful.

https://g8jnj.net/33ft%20Verticals%20and%20Ununs.pdf

Hi there to both Alans. Alan Pilot, what a true newbie I really am...duh...yes, I did discover just before Keith replied to myself but thanks anyways. Awesome. Alan the Mirror Man, yes indeed. I too have read the good, the bad and the indifferent. The problem really is that I absolutely have to head skywards I am afraid. I figured, rightly or wrongly, I could use this antenna, namely the Comet CHA-250BX11 for both my ham rig and my CB rig (yet to be purchased. Yes, I figure I will need another ATU for the CB rig and of course appropriate switching gear but my options are now so limited as explained in another part of the forum. My wife and her new garden and the local friendly parish council. I would truly love to hear if anyone knows of a better, ATU tunable, vertical. I simply am unable to be climbing ladders once the vertical is up and installed. Again, so very many thanks to everyone, you really are all helping no end.

If it fits the bill you should give it a try and see how you get along, being aware of the issues going into it the modifications seem simple enough and are clearly laid to if you have issues, the addition of ground wires seemed to resolve the gripes I did read about.  I spoke to a chap recently using a Mount Himalaya who told me he could get down to 40m on it with his tuner, I looked at the verticals with traps that get some decent reports but they were considerably more expensive.  Part of the fun of the whole thing is getting the new antennas up tuned in and modded if required, I think you should give it a bash there is plenty of good advice well laid out to overcome any stumbling blocks you may face.  I just had a quick look and this site gives the Comet 250 as its top pick so it must be doing something right.

https://www.radio4all.org/best-hf-vertical-antenna/

I have a Sigma SE-HF-360 vertical around the £130 price mark.
It is a 5.4m length fiberglass with a unun at the bottom.
Covers 3.5 to 30MHz and does work.
I only have it mounted at 16ft don't think they need to be up high.
Look it up it might fit the bill for you.
Did have that and a efhw long wire but just recently put a 7 band cobweb up at a hight of 4 meters and very surprised how well it works.
Ps ignore any spelling mistakes i am dyslexic but you will get what i say lol.

Alan, hi again. You know what? That is the very first antenna I looked at for resolve. Recommended by one of our most learned friends at Nevada. I then had cause to phone them back on some issue or another and this time got connected to Glen. It was he that recommended the Comet CHA-250BX11 and that has been the one I have been researching ever since. Hmmm...blinkin antennas eh? Again, you guys really are the very best and it is my reckoning that between us all we will come up with the perfect solution. Did I just say perfect in the same sentence as antenna?

There’s some interesting reviews on that antenna on eHam, but this one seems quite balanced:

https://www.mwrs.org.au/2014/09/08/cha-250b-review/

I know you have to go vertical, but is there a reason for this particular antenna?  You have other options like a 43’ vertical using the std 9:1 matching balun (and probably a tuner for good measure) or even a tuner like an AH-4 or Yaesu equivalent, with as much wire off it as you can manage, going vertical on either a fibreglass pole or strung up somewhere?  Just ideas…..

problem is.
You get good and bad reviews and it does your head in lol.
One thing i forgot to say was it does bring some noise in but not bad but i think you get that with a vertical well i seem to.
Solar panels- wifi- phone chargers- and the rest of the tec gadgets you know what i mean.
Perfect ? Antenna ? well the one for our tv is not bad lol.

Linda my wife is ok with the cobweb strapped to the garden swing (strange i know).
She is not at all keen on the 2 verticals i have the second one is for 2m/70cm.

Alan, you are so blessed, you really are. Fiona, my wife, informs me she is never going horizontal again UNLESS I go vertical. My options really are very limited.

She is bluffing lol.