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-   -   Damaged by a lightning ? (https://www.radiobanter.com/antenna/1129-damaged-lightning.html)

Jack Painter January 31st 04 01:29 PM

Mark:

"Mark Keith" wrote in

Thanks to all responding. A 20m antenna on top of the tower was

demolished,
pieces landing 100' away. That one single feedline was connected and
operating a wx-alert system in the shop.


Big omission... I now think the tower was hit, and piped the energy to
the wx-alert system which then routed it to the rest of the house via
the power wiring. Was that coax routed down to and snubbed to ground
at the base of the tower? From the damage, it almost sounds like it
was elevated in the air from the tower to the shop.


That feedline went underground at base of tower with all the rest. At the
main feedline disconnect point (20' from tower and about 50' from shop), it
went toward shop with two other feedlines, only the 20m was connected and
running SkyWarn. Skywarn tranceiver was powered by pair of 12vdc batteries,
which had a smart-charger (float) charge connected via AC power. All of that
equipment was destroyed including things near to it and not connected.

I bet the wx-alert box was the point where it got into the ac wiring.
I just can't see lightning energy traveling towards the house on a
coax that is on the ground. Once the lightning is at ground, normally
it should stay there. It's where it wants to go. I don't see it
ignoring the ground and radials at the tower, and preferring to go
towards the house on the coax, if the coax wasn't even connected close
to the tower. "I assume it was unhooked, and just laying on the
ground."


All other feedlines to shop and house were laying diconnected at the two PVC
risers coning up out of ground about 20' from base of tower, 50' from shop.

I wouldn't leave any more unprotected feedlines hooked up during
storms. I think all would have been ok, if not for that. Or at least
assuming there was no strike on the power lines a short distance from
your house when this happened. MK


Cable tv was knocked out for nearby homes as well, one or more utiilty poles
may have been hit at the same time.

On the 20m, It only takes one occurrence of bad judgement.

Jack



Gary Peach January 31st 04 10:29 PM


"J. Harvey" wrote in message
m...
"Roger Halstead"
Rarely does the system suffer damage.

...one computer...
...one PolyPhaser...
...a repeater antenna...
...a section of 5/8ths inch Heliax...
...every bit of water proofing...
...all the silver plating...
...a two meter rig...
...a barrel connector (N type)...


Geesus H. !


I saw the result of a lightening strike at Barkway on Royston Heath.
The lightening came down our waveguide without any damage but inside teh
equipemy huit it vapourised teh big circuit breaker on teh wall and left a
hole wher it had been and chared melted wires some distance above and below
wher the box had been mounted.



I guess so long as you think that you're happy,
then you're happy. ;-)


cogito ergo sum

Only some 3,000 years earlier.

Gary7SLL



Jock February 1st 04 12:31 AM

On Sat, 31 Jan 2004 22:29:19 +0000 (UTC), "Gary Peach"
wrote:


"J. Harvey" wrote in message
om...
"Roger Halstead"
Rarely does the system suffer damage.

...one computer...
...one PolyPhaser...
...a repeater antenna...
...a section of 5/8ths inch Heliax...
...every bit of water proofing...
...all the silver plating...
...a two meter rig...
...a barrel connector (N type)...


Geesus H. !


I saw the result of a lightening strike at Barkway on Royston Heath.
The lightening came down our waveguide without any damage but inside teh
equipemy huit it vapourised teh big circuit breaker on teh wall and left a
hole wher it had been and chared melted wires some distance above and below
wher the box had been mounted.


Can't think of a better place for "lightening" to strike than Barkway.

I kate it you where in eht RAF hewn all this happened?

--
Jock.

Gary Peach February 1st 04 08:56 AM


"Jock" wrote in message
...
On Sat, 31 Jan 2004 22:29:19 +0000 (UTC), "Gary Peach"


wrote:


"J. Harvey" wrote in message
om...
"Roger Halstead"
Rarely does the system suffer damage.

...one computer...
...one PolyPhaser...
...a repeater antenna...
...a section of 5/8ths inch Heliax...
...every bit of water proofing...
...all the silver plating...
...a two meter rig...
...a barrel connector (N type)...

Geesus H. !


I saw the result of a lightening strike at Barkway on Royston Heath.
The lightening came down our waveguide without any damage but inside teh
equipemy huit it vapourised teh big circuit breaker on teh wall and left

a
hole wher it had been and chared melted wires some distance above and

below
wher the box had been mounted.


Can't think of a better place for "lightening" to strike than Barkway.

I kate it you where in eht RAF hewn all this happened?


No, Engineer (Microwave) with PYE Telecommunications
We had teh first non GPO television microwave link between Birmingham and
London.
We were trying to break teh GPO monopoly on supplying and also regulating
radio communications.
It must have worked because the GPO /BT is no longer the only supplieer.

CML building Birmingham, Meriden, Cold Ashby, Barkway, Hill Crest (Highgate,
just down teh road from the BBC station at Swains Lane)
We were contracted to ATV.
Teh Link was used to show the adverts going out in Birmingham to the
sponsors in London.

Thanks for taking the **** out of my creeping disability, It keeps a sens of
proportion for me,
console yourself that it won't last much longer and I won't be able to type
at all.

Gary7SLL



Roger Halstead February 1st 04 07:21 PM

On 30 Jan 2004 14:57:22 -0800, (J. Harvey) wrote:

"Roger Halstead"
Rarely does the system suffer damage.

...one computer...
...one PolyPhaser...
...a repeater antenna...
...a section of 5/8ths inch Heliax...
...every bit of water proofing...
...all the silver plating...
...a two meter rig...
...a barrel connector (N type)...


Geesus H. !


Considering three strikes a year on average and this is not all the
same strike, and all but the antenna and Heliax have been
inexpensive...Yup.

I've had line noise trash a computer on a sunshiny day. Lost
everything except the CPU of all things.

Computers run 24 X 7 (bout 32,000 hours run time a year) and are hard
wired together with Cat 5 cable.
No problems since going to UPSs with line conditioning.

Last Fall, this one had over 57 transfers to the UPS over 3 months
including 3 brown outs, one black out (quite a few hours), and the
rest was line noise.


I guess so long as you think that you're happy,
then you're happy. ;-)


Every thing is relative. :-))

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com


Carry on then.



Jack Painter February 2nd 04 01:37 AM

"Roger Halstead" wrote
Computers run 24 X 7 (bout 32,000 hours run time a year) and are hard
wired together with Cat 5 cable.
No problems since going to UPSs with line conditioning.

Last Fall, this one had over 57 transfers to the UPS over 3 months
including 3 brown outs, one black out (quite a few hours), and the
rest was line noise.


I too had at least that many momentary high line-noise and brownout shifts
to APC since Hurricane Isabel last September. But my computer runs in real
time, so it could only get 8,736 hrs in a year if I left it on all the time
:-)

Jack



Roger Halstead February 2nd 04 06:53 AM

On Sun, 1 Feb 2004 20:37:24 -0500, "Jack Painter"
wrote:

"Roger Halstead" wrote
Computers run 24 X 7 (bout 32,000 hours run time a year) and are hard
wired together with Cat 5 cable.
No problems since going to UPSs with line conditioning.

Last Fall, this one had over 57 transfers to the UPS over 3 months
including 3 brown outs, one black out (quite a few hours), and the
rest was line noise.


I too had at least that many momentary high line-noise and brownout shifts
to APC since Hurricane Isabel last September. But my computer runs in real
time, so it could only get 8,736 hrs in a year if I left it on all the time


Note that was computer(s) as in plural. I have 4 :-))

Roger Halstead (K8RI & ARRL life member)
(N833R, S# CD-2 Worlds oldest Debonair)
www.rogerhalstead.com
:-)

Jack




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