[TowerTalk] Coax

[TexasRF at aol.com]

Hi y'all, the receive side of the coax loss is not nearly as bad as the  
transmit side. This is because of all the back ground noise on the HF bands. 
The  noise from the heavens alone is on the order of +20 dB at 28 MHz and 
increases  as the frequency is lowered.
 
So, the S3 signal is lowered 3 dB by the coax loss and the sky noise is  
lowered by 3 dB as well. Still have about the same signal to noise ratio; just 
a  lower S meter reading.
 
It takes a lot of coax loss on HF receive to make a noticeable difference.  
There is a much different scenario at VHF,UHF and microwave. All this can  
be calculated to within .001 dB if you wish but that is a different  subject.
 
73,
Gerald K5GW
 
 
 
 
 
 
 
In a message dated 4/8/2012 11:35:36 P.M. Central Daylight Time,  
Charlie at TheGallos.com writes:


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

...snip...

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)

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