Jim,
The tower is out in the middle of the country and he does not have a
traditional shack. The steel valve box is the shack/equipment room,
which happens to be made out of steel, that he's trying to use to his
advantage.
Trent won't be there to unplug cables like I/we can when a thunderstorm
approaches. He's attempting to come up with the best possible lightning
protection that he can in his situation.
Rich - N5ZC
On 8/28/2016 2:24 AM, Jim Brown wrote:
Trent,
Your first problem is that your box is NOT a shield if cables come
through openings in the box without their shield being bonded to the
box at the point where they enter. You must also bond or bypass (with
feedthrough caps) all other leads coming into the enclosure, like
power, control lines, audio lines, keying lines, etc. Any one of these
lines that does not have its shield bonded to the enclosure or come
through the enclosure via a feedthrough capacitor destroys the shielding.
As to where to put the Polyphasers -- I would use the "feed through"
type and bond them to the enclosure.
The larger question is why you need a Faraday cage in the first place.
Few stations do. What most stations need is proper BONDING, proper
grounding, proper power, and proper interconnections between
equipment. Study http://k9yc.com/GroundingAndAudio.pdf
73, Jim K9YC
For On Sat,8/27/2016 10:28 PM, trentkd5ia--- via TowerTalk wrote:
My remote station is approaching completion. A 70' tower, wireless
internet, solar power and RemoteRig with a TS480 is all operational.
Still in progress are the antennas to be mounted, and lightning
protection. I have a question about grounding. The electronics are
housed in a valve box--a galvanized steel cylinder 5 feet in diameter
and 4 feet tall, with 3 1/2 feet of that in the ground. A removable
steel lid covers it. All cables are in PVC pipe and enter the
housing under ground level, and the valve box is 12 feet from the
base of the tower.
The grounding system will consist of 9 ground rods, 3 connected to
each leg of the tower and extending out from the tower. The valve
box will also be connected to the grounding system. Polyphasers will
protect against surges.
My question is, can I install the surge protectors inside the steel
housing, or should they be mounted outside the valve box? I'm
thinking that the steel cylinder possibly acts as a Faraday cage, and
the grounding connection and surge protection should be attached on
the outside wall of the housing. Any comments or suggestions, please?
Thanks!
Trent K5XM on the windy and lightning prone West Texas plains
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