Anyone's gear actually been hit by lightning?


#1

G’day all,

I see a lot of talk about lightning protection for our antennas/receivers etc but was wondering if anyone has actually suffered a strike directly to their gear? I don’t have any protection yet other than the non-conductive pvc tube containing the antenna and my pi is connected to my home network wirelessly. It’s not good to risk it of course but I would like to hear others stories.

Cheers,

Goldy

**My setup:
8 element homemade colinear antenna made from quad shield RG6 F connector-> 5m RG6 quad -> TV masthead amp -> Power injector -> 1m RG6 quad -> 1090Mhz BP filter -> Noonelec DVB rxer -> Raspberry Pi B+ running Piaware.

Best distance so far: 475Km**


How am I looking?
#2

I feel lucky with respect to lightning.
All my installation, including antenna is indoor and immune to harshness of weather :smiley:


#3

My setup:
homemade cantenna made from 355 mL Pepsi can (66 mm dia), height cut to 69 mm + Whip 69 mm + F barrel connector -> 5m RG6 -> Noonelec DVB rxer -> Raspberry Pi Model2 running (Raspbian Wheezy+dump1090-mutability+Piaware data feeder).

WITHOUT AMPLIFIER
Best distance so far: 260 nm = 480Km


#4

Yeah, I wish I could mount my antenna inside but my roof is lined with sarking (thermal foil insulation) which is a great signal blocker so outside it is. Considering the terrain around my site and the 39m ASL height, I’m pretty happy with the range I’m getting. That said, like all ADSB-ers, range is the goal.

I’m going to give the cantenna a go for sure and see how it goes, been meaning to for a while but life with a family and three jobs leaves little time…

Thanks abcd!


#5

of course you have to connect an outdoor antenna mount to your standard earthwire. but all other kind of lightning protection in my opinion is nonsense. a real lightning protection needs three stages - and real equipment for this job costs more than 50 times what your pi costs. using wifi to connect to your network i think you are perfect save and worst case is 150$ damage of your pi with dongles, amplifier and sd-card :slight_smile:


#6

You need to correctly ground. Anyone who gets directly struck is not trying to avoid equipment damage. They are trying to avoid the entire house burning down. I do know someone who got a direct strike. Everything electric related was destroyed, but the house didn’t burn down. You also need correct grounding to prevent a static charge build up. Static will damage your equipment and it only takes wind to cause it. No lightning required.

See the following link for a simple guide:
http://www.reeve.com/Documents/Articles%20Papers/AntennaSystemGroundingRequirements_Reeve.pdf


#7

Yes. Best thing to do is disconnect and isolate.


#8

hmmmm - i’d think every owner of a datacenter - and many other would disagree here :slight_smile:


#9

[quote=“TomMuc”]

I’m talking about residential. If you would like to talk about commercial, we can. But that is not the topic. Hint, remove any voltage potential across the equipment during the strike.


#10

lost an amplifier on one of our sites during an electrical storm his past summer. A direct hit would have been a bigger deal.


#11

EVEN IF YOUR HOUSE DOES NOT HAVE AN ANTENNA, LIGHTNING CAN STRIKE.

THE DAMAGES SHOWN IN PHOTOS BELOW ARE CAUSED BY LIGHTNING STRIKE.

THINK OF PROTECTING YOUR HOUSE FIRST, AND PROTECTING YOUR RASPBERRY PI & DVB-T DONGLE LAST.


#12

In our domestic situations you can reduce the likelihood of a lightning strike but in the end, lightning will go where it damn well pleases! Commercial and industrial sites can of course build lightning arrestor towers and rods etc but these are well outside most of our means.

I’ve had some pretty intense electrical storms at my location without any side effects at all other than a short period of reduced range on my receiver setup, so I’ll stick with my current setup for now, just changing antennas and checking results as time permits.

Cheers.

**My setup:
8 element homemade colinear antenna made from quad shield RG6 F connector-> 5m RG6 quad -> TV masthead amp -> Power injector -> 1m RG6 quad -> 1090Mhz BP filter -> Noonelec DVB rxer -> Raspberry Pi B+ running Piaware.

Best distance so far: 475Km**


#13

It will be nice if you post photos of your setup.

It is a good idea to try different types of antennas. For the comparison to be realistic, the test setup should be;
(1) with short length of coax (your setup already meets this condition).
(2) without amplifier, as by boosting the weak signals, amplifier can make a poor antenna to perform like a good antenna.


#14

Hi guys,

This makes me slightly nervous…

I’ve just moved my antenna to the roof ridge, so it sticks up above the roofline.

My antenna feeds into an amp, with a power inserter powering.

The whole rig (Rpi, amp, etc etc) is run off a spur off the lighting ring in my attic, using 10amp cable.
Like all the rings, the lighting ring is terminated in the central house fuse box.

(I’m aware the lighting ring / fuse is low rated, so I wont be putting any heaters or high drawer items on it.)

When we say…

“of course you have to connect an outdoor antenna mount to your standard earthwire”

I take it that as the amp is connected to earth through it’s power supply (UK 3-pin plug), this is what we mean?

Is this adequate?


#15

Of course, in my case, although the antenna is earthed (through the amp supply), the mount itself isnt…

Whats the simplest way to earth the mount itself?


#16

the earth wire is the absolute must - and no insurance will ever pay anything without:

Suitable as ground conductors are:
– a single solid wire with a cross-section of at least 16 mm2 copper, at least 25 mm2 aluminium or at least 50 mm2 steel.

https://www.kathrein.de/fileadmin/media/content/07-Satelliten-%20und%20terrestrische%20Empfangssysteme/antenna_earthing.pdf

http://electrical-engineering-portal.com/lightning-and-surge-protection-for-cable-networks-and-antennas-for-tv-part-2


#17

I wouldn’t be surprised if that wasn’t true - so much stuff is double insulated nowadays.

But then you’re in the UK and so many people have still got a TV aerial on the chimney, and that just has a connection to a TV in the living room, and no one worries.

There’s nothing wrong with putting a double 13A socket onto the lighting circuit - in fact it’s quite a common way to connect TV antenna amplifiers, if someone were to plug a device in that takes too much current a breaker would just trip. Just put a label on the socket to say that is is wired to the lighting circuit, maximum load 2A

I’d run an earth wire from the antenna shield to the earth pin on an otherwise unused 13a plug … just to protect the Pi from any static that might build up on the antenna.


#18

Thanks PeterHR,

Good to hear from someone else in the UK!

The US specs seem pretty rigorous…

I’ve got a “pet sparkie” coming out to give me his thoughts soon, so I’ll let you know what he says.

Mainly worried about “burning the house down” and “nulifiying house insurance”…

I’ll take a look at earthing the antenna as you suggest tho.

As you say though, having cast on eye sky-ward on walking past other houses, TV antennas much higher than mine seem to have no additional protection…

C


#19

I dont know how far this is true, but in any case, it is an interesting story. :slight_smile: :smiley:
Texas Bar Sues Local Church Over Lightning Strike
A bar called Drummond’s, in Mt Vernon, Texas began construction on an expansion of their building, hoping to “grow” their business. In response, the local Southern Baptist Church started a campaign to block the bar from expanding - petitions, prayers, etc. About a week before the bar’s grand reopening, a bolt of lightning struck the bar and burned it to the ground! Afterward, the church folks were rather smug - bragging about “the power of prayer”. The angry bar owner eventually sued the church on grounds that the church … “was ultimately responsible for the demise of his building, through direct actions or indirect means.” Of course, the church vehemently denied all responsibility or any connection to the building’s demise.

The judge read carefully through the plaintiff’s complaint and the defendant’s reply. He then opened the hearing by saying: “I don’t know how I’m going to decide this, but it appears from the paperwork that what we have here is a bar owner who now believes in the power of prayer, and entire church congregation that does not.”


#20

I ran my coax to a grounding block and from there I have a #6 copper line going to a ground rod. I went a little overboard and bonded that one to a couple more around the property for extra protection. Figure the minimal cost of some protection can’t hurt. Lightening is a beast and no matter what you do, it can find a weak spot, unless you have an unlimited budget.

With the cost of copper down, go to a scrap yard and you can pick up the copper REALLY cheap right now. It’s a whole lot cheaper doing it that way than running to the big box Home Depot/Lowes.
Just my opinion and what I’ve done. The scrap yard is an awesome place to find goodies though.