You can have up to a 2:1 mismatch (SWR) at the transmitter using 75 ohm line
if the antenna is a flat 50 ohms. If your 75 ohm line happens to be a
multiple of a quarter wave length that will transform the 50 ohm load to 100
ohms seen at the transmitter end.
> -----Original Message-----
> From: email@example.com [mailto:towertalk-
> firstname.lastname@example.org] On Behalf Of Grant Saviers
> Sent: Monday, July 19, 2010 3:54 PM
> To: Towertalk@contesting.com
> Subject: Re: [TowerTalk] 75ohm cable
> Lucky you! I moved and lost my source.
> You can use a coax matching section at the antenna if they are
> monobanders, this works fine and you need a flexible loop anyway. I ran
> 7/8" CATV hardline 350' to a 2m yagi with a very good match. The
> calculations are in most every handbook. The transmitter mismatch
> should not be a problem. A no tune semiconductor linear may foldback
> with 75 ohms but it would be a finicky one. Any PI network linear should
> work fine.
> This hardline also makes superb low loss broadband dipoles, using the
> shield as the element and the (usually copperweld) center conductor as
> the messenger wire.
> The compression plumbing fittings are the cheapest way to adapt to PL's.
> Grant, KZ1W
> Carol Richards wrote:
> > I am the proud recipent of numerous rolls of 75 ohm, 1/2 in CATV cable.
> Since all of my antennas require 250ft or mor runs this is a real
> blessing. I have a few questions before I start replacing the RG 213.
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