-----Original Message-----
From: Samuel Strongin <[EMAIL PROTECTED]>
RG6 is 75 ohm cable. Why would you buy a great radio and worry about
performance,then go use the wrong cable. You >start out at a 1.5:1 swr.
Because RG-6 may not be the "wrong cable", and the SWR may not be 1.5
to 1.
IMHO, the question of what cable to use requires evaluating the entire
antenna/transmission line *system* and taking all the issues into
account. Depending on the antenna impedance, frequency, length of line
and comparison coax, RG-6 might be lower loss than 50 ohm line (say,
RG-58 or even RG-8X).
For example, suppose I had a wire dipole at a height such that the
feedpoint Z was 75 ohms, and it needed a long feedline to reach the
shack. Feed it with RG-6 and the SWR on the line will be 1:1. All I
need to do is match that 75 ohms to 50 ohms at the shack, which can be
done with an unun or the ATU in the rig. With 50 ohm cable the load SWR
will be 1.5 to 1, and I'll probably still need to match it at the shack
end - but the shack-end Z can be anything inside the 1.5 to 1 SWR
circle on the Smith Chart. Depending on the line used, the loss with 50
ohm cable may be greater, too.
73 de Jim, N2EY
________________________________________________________________________
Email and AIM finally together. You've gotta check out free AOL Mail! -
http://mail.aol.com
_______________________________________________
Elecraft mailing list
Post to: [email protected]
You must be a subscriber to post to the list.
Subscriber Info (Addr. Change, sub, unsub etc.):
http://mailman.qth.net/mailman/listinfo/elecraft
Help: http://mailman.qth.net/subscribers.htm
Elecraft web page: http://www.elecraft.com
