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Re: [TowerTalk] Cable TV hardline question

To: Tim Holmes <W8TAH@Zoominternet.net>, towertalk@contesting.com
Subject: Re: [TowerTalk] Cable TV hardline question
From: "Bob Pack, NX5M" <nx5m@txcyber.com>
Date: Fri, 29 Oct 2004 11:12:31 -0500
List-post: <mailto:towertalk@contesting.com>
More info that I forgot to put in the last message:
For 20m I used 44.7 inches of RG11 and 44.7 inches of RG213.  The 213 goes 
between the hardline and the RG11 jumper.
Calculations are available in an excel file.....if you would like it email 
me directly and I'd be happy to send it to you.


Bob NX5M


On Fri, 29 Oct 2004 11:33:28 -0400, Tim Holmes <W8TAH@Zoominternet.net> 
wrote :

> Yeah, thats what I was worrying about-- If anyone has any good 
> suggestions, I would love to hear them,  I hate to have this stuff just 
> sitting around, not doing anything.
> 
> Tim
> 
> >I would be concerned also, since the cable can cause an SWR
> >of over 2:1 at the radio.
> >Most VHF and UHF radios do not tolerate such a high SWR this
> >very well.
> >
> >What you can do is build a transformer using lengths of 50
> >and 75 ohm cable mixed. It is pretty tricky to do this at
> >UHF, but it can be done if you have the test gear and are
> >careful. I don't have references, but I'd bet someone else
> >does. The devices are called non-synchronous transformers.
> >
> >I certainly look into matching the cable at VHF or UHF, not
> >because of cable loss but because of bandwidth and impedance
> >problems at the radio. A 2:1 SWR is not good for most
> >radios.
> >
> >73 Tom
> >
> >  
> >
> _______________________________________________
> 
> See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless 
Weather Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any 
questions and ask for Sherman, W2FLA.
> 
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> 
> 
> 
> 
_______________________________________________

See: http://www.mscomputer.com  for "Self Supporting Towers", "Wireless Weather 
Stations", and lot's more.  Call Toll Free, 1-800-333-9041 with any questions 
and ask for Sherman, W2FLA.

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