It shouldn't matter where the line of demarcation is between open coax and the
coax running through the conduit. Whether you run the conduit to the top of
the tower and put your polyphasers at that point OR run the conduit to the base
of the tower and place the polyphasers at that point OR run conduit through the
house and place the polyphasers at the entrance point its all about providing
that alternate path for lightning that doesn't pass through your hamshack. At
that boundary point between coax and coax in conduit nothing should pass that
isn't decoupled to provide that alternate path for the lightning. Don't
carefully ground and polyphaser all the coax cables at this point and then just
loop the rotor cable around it which would provide an unfiltered path for
lightning straight into your shack.
Not sure how large the inductively coupled component of a strike would be but I
would assume that it would be smaller on your short run of coax as compared to
the coupling to very long power lines that are probably coming into your home
without any filtering.
Earl
N8SS
------------------------------
Message: 8
Date: Wed, 7 Aug 2013 11:34:54 -0400
From: john@kk9a.com
To: towertalk@contesting.com
Cc: wewill747@gmail.com
Subject: Re: [TowerTalk] FIRST TOWER & 2ND FLOOR SHACK --HELP
Message-ID: <0da7d0eb6d0651e4d80317b298f23a76.squirrel@www11.qth.com>
Content-Type: text/plain;charset=iso-8859-1
I also have a 2nd floor station, I have no RF ground. W8JI has information
in his site regarding second floor grounding
http://www.w8ji.com/second_floor_grounding.htm
John KK9A
To: towertalk@contesting.com
Subject: [TowerTalk] FIRST TOWER & 2ND FLOOR SHACK --HELP
From: Wayne Willenberg
Date: Wed, 7 Aug 2013 09:22:03 -0400
My *first tower* (a 100? crank-up including the mast) is scheduled to
arrive in mid-October. It will be located 150? from the base of my house.
The problem is, *my shack is located on the second floor of my house*. So,
all cables that will go to and from the tower first go through the second
floor wall, down the exterior wall (a distance of about 20?) to a central
grounding point.
I just finished reading a technical note from PolyPhaser called ?Ham Radio
Station Protection.? It suggested for my situation (i.e., shacks that are
above the basement) that coax, ground strap and rotor cables that run
vertically up my outside wall Might inductively couple some energy from the
tower, if it was struck by lightning, to the shack.
The article suggested having all of the cables go through surge protectors
at the base of the tower and then run through EMT (electrical metal tubing)
that is grounded to the tower base *only *and runs all the way from the
tower base to the second floor shack. The article says the EMT will act
like a *Faraday shield* for the cables inside.
I can understand this approach for the vertical run up the exterior wall of
my house, but does it make sense to use EMT all the way from the tower?
How about the 2? ground strap that will run from the ground protection
system around the base of the tower to my shack. Following this logic,
shouldn?t it be inside the EMT?
Any help would be greatly appreciated.
Wayne, KK6BT
------------------------------
Message: 9
Date: Wed, 07 Aug 2013 10:42:49 -0500 (CDT)
From: Gene Smar <ersmar@verizon.net>
To: K7LXC@aol.com, towertalk@contesting.com, patrick_g@windstream.net
Subject: Re: [TowerTalk] Book on Towers
Message-ID: <9249561.1941559.1375890169476.JavaMail.root@vznit170134>
Content-Type: text/plain; charset=UTF-8
Patrick:
I ordered a Trylon Titan 500-64 from Steve in 2001. He was very helpful before
and after the sale, answering my questions about my own first tower
installation. As for the product itself, if I needed a second medium-duty tower
I wouldn't hesitate to buy another Trylon. I built it myself from individual
angle pieces (I was able to buy it cheaper broken down into pieces and not
factory assembled.) I am aware of the wind load design limits to the tower and
have not overloaded it. It's been up in my suburban back yard since the fall of
2001. Steve and Trylon are a combination worth considering.
73 de
Gene Smar AD3F
On 08/07/13, K7LXC@aol.com wrote:
> I have ordered "Up The Tower" and expect it to be a great source of
practical information.
You are correct, sir.
> I am curious though. With all the positive
commentary regarding the book and the author that I have read here I find
it
interesting that I don't see the brand tower he sells mentioned in emails
on
this site. Just curious, what is the "general take" on the towers he
sells?
Champion Radio Products (K7LXC, Proprietor) mostly sells the Trylon
Titan self-supporting towers. Best value for the money for a free standing
tower. I can get Rohn products but they're such a commodity there's no margin
left in it for us little dealers.
Cheers,
Steve K7LXC
TOWER TECH
and
Champion Radio Products
Cell: 206-890-4818
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------------------------------
End of TowerTalk Digest, Vol 128, Issue 31
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