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Re: [TowerTalk] Antenna Distance From Shack

Subject: Re: [TowerTalk] Antenna Distance From Shack
From: <>
Date: Wed, 16 Aug 2006 22:25:04 -0400 (EDT)
List-post: <>

Lets assume your total coax cable length is 500 feet from your transmitter, out 
to your tower, up the tower, then to the C31XR feedpoint.

Here are the loss figures in feet per dB for various common coaxial cables:

             14.0  21.0  28.0  
LDF5-50A     714   588   526   
3/4" CATV    769   588   435  
LDF4-50A     588   400   323 
9913         220   190   155   
RG-213       130   100    83

As you can see, RG-213 would have just over 6 dB of loss on 10 meters, and 
nearly 4 dB on 20 meters.  You would do about as well with a dipole immediately 
next to your house!  Even 9913 has over 3 dB of loss on 10M and almost 2.5 dB 
on 20M.  However...  notice that good old 3/4 inch 75 ohm CATV cable performs 
really well, with  slightly over 1 dB of loss in your situation.   If you're a 
purist, you could purchase 500 feet of Andrew LDF5-50A, but that would set you 
back about the same amount as your tower and beam!


---- Original message ----
>Date: Wed, 16 Aug 2006 20:55:40 -0400
>From: "Tom Crothers" <>  
>Subject: [TowerTalk] Antenna Distance From Shack  
>To: <>
>Hello Fellow Tower Talkians,
>I'm placing a 65 ft. tower with a C31XR on top, approximately 400 ft from my
>shack in the house.  I've always used RG-213 or RG-8U in the past to this
>Yagi, (but I've never had the tower that far away before either).  Anyone
>see a problem continuing to use the same coax with that distance?
>TowerTalk mailing list

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