[TowerTalk] Lightning protection

[K8RI]

On 7/8/2013 10:45 AM, K8RI wrote:
> On 7/8/2013 8:06 AM, Jim Thomson wrote:
>> Ok, I’ll bite.   What do AM /FM /TV broadcast folks do or use for
>> lightning protection ??
>> Esp with real high towers involved in some cases.   They don’t shut
>> things off and toss cables
>> out the window.   And ditto with cell sites and microwave sites.
>> They are all left on 24-7-365.
>>
>> IE: what do the big boys use ?   Why not copy their procedures ?
>
> They do nothing magical, but they carry the grounding system, and single
> point ground to an extreme.  IE: the transmitter "house is usually laid
> out to take advantage of the SPG.  I have over 600 feet of bare #2 run
> in a star pattern from the towers and most everything goes point.

I was in a hurry and missed the point where I have 32 or 33 8' ground 
rods CadWelded to that 600 feet of bare #2

All coax has the shield grounded at the top and bottom of the 100' tower 
as wrll.

73

Roger (K8RI)


> Unfortunately through the grounding panel at the entrance is on the
> opposite side of the house from the power entrance.
>
> So the commercial station would "probably" have several thousand feet of
> grounding cable, duplicates/back ups for everything possible and a spare
> tube on hand.  They use "spark gap" devices on the coax which I've seen
> as large as 4". Also, they have a rugged transmitter and no receivers.
>
> As others have said, It's most likely well beyond cost effective for a
> ham station so many of us really do as much as we can afford to emulate
> the commercial installation.
>
> Judt do remember it's not uncommon for them to get knocked off the air.
>   Then the delay is usually the time it takes maintenance to drive out
> to the site, turn the breakers back on and let the transmitter(S) warm
> up.  Some have back up transmitters.
>
> 73
>
> Roger (K8RI)
>
>>
>> Jim   VE7RF
>>
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