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
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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