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Re: [TowerTalk] Coax

To: "Charlie Gallo" <>
Subject: Re: [TowerTalk] Coax
From: "Jim Thomson" <>
Date: Sun, 8 Apr 2012 23:49:22 -0700
List-post: <">>

-----Original Message----- 
From: Charlie Gallo
Sent: Sunday, April 08, 2012 9:35 PM
To: Jim Thomson
Subject: Re: [TowerTalk] Coax

On 4/9/2012 Jim Thomson wrote:

...snip...   You end  up with 3 x choices.  (a) increase the
> power output,  and-or replace amp with a much bigger one,
> like double the capacity.  (B)  obtain much bigger coax.    C   use a 
> combo of A+B


Actually, that only makes up the transmit side - that S3 signal just above 
the noise goes down 3 dB too.  I think fighting for the Rx signal is just, 
if not more important

73 de KG2V - Charles Gallo
Quality Custom Machine-shop work for the radio amateur (sm)

##  Point well taken!     That's  why I said  sigs lost in the coax are lost 
forever..and that's  in both directions.
A bigger amp  buys you nothing on RX of course.... unless ur a Broadcast 
station, but that's a moot point.
The vhf-uhf  fellow's  will mount the Rx pre-amp at the top of the tower, to 
eliminate the coax loss.
Even with a tower mounted RX pre-amp, you will still lose a bunch on TX, so 
you may as well just use lower loss-bigger
coax to start with.

##  that flexible aluminum corrugated  shield +  corrugated copper center 
conductor  coax, similar to heliax, made by RFS..and sold by Davis RF
is a winner.    Cheap, and comes in 2 x  sizes, .875 inch  and also 1.125 
inch.   WAY  more flexible than plane jane heliax, with its copper tube 
center conductor.
It's  very light  vs  regular heliax, since  aluminum is only one third the 
weight of copper.   The combo of the corrugated copper center conductor  + 
aluminum outer conductor  makes for a very flexible and easy to work with 
cable.   Then just install  7-16 dins on the ends.   The AL stuff just 
described is all the
rage in the cell industry.

later... Jim  VE7RF 


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