Towertalk
[Top] [All Lists]

Re: [TowerTalk] Measuring Coax Length

To: "TT TowerTalk" <TowerTalk@contesting.com>
Subject: Re: [TowerTalk] Measuring Coax Length
From: "Gary - AB9M" <glhuber@msn.com>
Date: Tue, 28 Oct 2014 21:25:12 -0500
List-post: <towertalk@contesting.com">mailto:towertalk@contesting.com>
I used 9913 to feed a TH-7 at 50 feet for over 20 years with no water intrusion. I did however use a rotor loop with solid dielectric, a double female UHF connector to splice the two PL-259 connectors terminating the two cables and a waterproof covering of multiple layers of Scotch High Voltage rubber splicing tape, 88 tape, and Scotch Kote. When the cable was taken down and the splice opened there was NO sign of water in the splice or the 9913.

If you got water in 9913, you'll most likely get water in other cables as well IF you use PL-259 connectors and fail to provide a waterproof covering.

BTW, we average 40 inches of rain per year at my QTH.

73 & DX,

Gary - AB9M

-----Original Message----- From: Matthew Kaufman
Sent: Tuesday, October 28, 2014 9:07 PM
To: john@kk9a.com
Cc: towertalk@contesting.com
Subject: Re: [TowerTalk] Measuring Coax Length

I would use 9913.. if I ran out of 1/2" water hose. Just remember to use hose thread fittings, not PL-259.

Matthew Kaufman

(Sent from my iPhone)

On Oct 28, 2014, at 6:31 PM, "john@kk9a.com" <john@kk9a.com> wrote:

I would not use Belden 9913 outdoors, especially if underground. Some
years back I also purchase 9913 but I threw mine away because it was too
susceptible to water ingress.

John KK9A


To:    Towertalk Reflector <towertalk@contesting.com>
Subject:    [TowerTalk] Measuring Coax Length
From:    Mike Fahmie via TowerTalk <towertalk@contesting.com>
Reply-to:    Mike Fahmie <wa6zty@yahoo.com>
Date:    Tue, 28 Oct 2014 21:15:55 +0000 (UTC)

Some years back, I purchased a 500' reel of Belden 9913 and used a bit
here and
there over the years. Now I needed four 70' runs to the base of my tower but
didn't know how much 9913 remained on the reel.
My DVM can measure capacitance so I connected it to the free end of the reel
and measured 6300 pF.  Belden says that 9913 capacitance is 24.6 pF/ft so
dividing that into 6300 pF implied that I had 256 ft remaining.  That was
enough for three 70' runs but not enough for four,  oh well.
I cut three 70' lengths from the reel, 45' of cable remained.  (3 x 70) +
45 =
255.  That is just 1 ft less than what was predicted by the capacitance
measurement !!!  Isn't it nice when the numbers work out so well.  Will I
rely
on that technique in the future? Nope, gotta see it work out like that a few
more times first!
-Mike-WA6ZTY
_________________

_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk
_______________________________________________



_______________________________________________
TowerTalk mailing list
TowerTalk@contesting.com
http://lists.contesting.com/mailman/listinfo/towertalk

<Prev in Thread] Current Thread [Next in Thread>