On Mon, 12 Apr 2010 21:07:25 -0400, Steve Bagley wrote:
>I am putting up a tower and will need to run about 500 feet of coax.
http://audiosystemsgroup.com/Coax-Stubs.pdf
500 ft is a LONG run. You can easily burn half your TX power (3dB) in the
coax. Many of us try to keep feedline loss under 1 dB. 500 ft of LMR400 is
3.3 dB on 10M, 2.3 dB on 20M. Half-inch heliax is 1.1 dB on 20M, 1.6 dB on
10M. To get under 1 dB on 10M you'll need 7/8-inch Heliax. :)
Another option to consider is CATV hardline. It's pretty low loss, it is 75
ohm cable, so there will be a bit of mismatch, but that's why God made
antenna tuners. It's often possible to get it free or cheap. You'll have to
buy or scrounge connectors and a tool.
Study the data on W3LPL's and K1TTT's website and save your pennies.
73,
Jim K9YC
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