88 feet? Not sure I understand what you're doing? If your Windom is fed with
ladderline, bring the ladderline up close to the house, then use two runs of
coax (or a pair of barrel connectors) to get thru the walls, then connect
more ladderline indoors and bring to your tuner.
There's no set size, you'll have to try it. In general, shorter coax
feedthroughs are better, but probably anything will work.
In my case, I have a a pair of 1/2" hardline runs which are about 8' long
which transition my 600 ohm open line across part of the deck and through
the hamshack wall. Works fine, and any impendence anomaly is easily
compensated by the tuner.
If you are proposing to use 88' runs of your tower-top coax lines in pairs,
to act as open wire line, I don't know what to expect from that. I have my
doubts about it, but the nice thing with ham radio is you can always try it!
I'd be concerned that long runs of paired coax will not have the
characteristics you want with open line. Also I suspect the coupling of long
lengths of coax shield will not do you any good.
GL es 73
Dan
K0DAN
-----Original Message-----
From: Hans Hammarquist
Sent: December 09, 2013 21:52
To: towertalk@contesting.com
Subject: [TowerTalk] Fwd: Ladder line entrance
How short is "short"? I have five coax from the shack to the top of the
tower. Each is 88 feet. Is that too long?
Hans - N2JFS
-----Original Message-----
From: K0DAN <k0dan@comcast.net>
To: towertalk <towertalk@contesting.com>; Hans Hammarquist <hanslg@aol.com>
Sent: Mon, Dec 9, 2013 10:46 pm
Subject: Re: [TowerTalk] Ladder line entrance
Yes, you can use coax lines as pathways for your ladder line to enter the
shack. Once in the shack you can continue the run of ladder line to your
tuner. The short lengths of coax will have minimal effects on the impedance
bumps caused. On the outside you can also install a couple spark plugs as
lightning surge arrestors and put some 1+ megohm resistors across them as
static bleeders. Works nice.
GL es 73
dan
k0dan
-----Original Message-----
From: Hans Hammarquist
Sent: December 09, 2013 21:36
To: towertalk@contesting.com
Subject: [TowerTalk] Ladder line entrance
As I will move my shack from being rather "primitive" to be more lightning
proof I need to figure out how to enter my ladder line from my Windom
antenna.
My access panel has multiple coax entries and I wonder now if I can use two
(2) coax cables to enter the ladder line.
Previously the ladder line "just" went through the wall with two wall
feed-throughs and I always disconnected the wires from my tuner and
connected them to a radiator in my old shack.
I am not willing to drill holes in my new shack (if I can avoid it) but
instead utilize two (75 ohms) coax cables, one for each pole on the ladder
line and put my tuner at the other end. An other solution woud be to move
the tuner outside the shack but that require a remote.
Anyone with experience?
Best 73 de,
Hans - N2JFS
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