Dave Platt wrote:
Well, I just got rg 8 cable about 20 feet for free! The thing about
it
it has two pl259 connectors on it. I need to have one end free so i
can
wire up the slim jim or j pole I build this weekend. I really do not
eant to cut the cable as I would like to use it when I put the
permanent station up. See any way around this?

Can I use copper house wire 12/ 2 or so to connect to the points on
the
j pole then bring them to a so connector Then screw the rg8 pl
connector into that?

Sure. One fairly common J-pole design uses an SO-239 socket which is
mounted directly on one of the copper pipes at the feedpoint (use a
brass screw or bolt, and then some plumber's solder). This creates
the ground connection. Then, just run a short piece of copper wire
from the center pin of the SO-239, across the space between the
pipes,
and solder it to the other pipe - this creates the "hot" side of the
feed. The feedline with its PL-259 plug is screwed into the socket,
and ends up sticking out to the side.

See http://www.tcars.org/elmer/jpole.html for one such design,
complete with a parts and materials list, and look at
http://www.alpharubicon.com/elect/jpolejaden.htm for another. One
design screws the SO-239 directly to the pipe, the other makes a
mounting bracket. Do whichever you prefer - when properly adjusted
and tuned the two designs should have performance so close to
identical that you cannot tell the difference.

Will this through off the swr? What ohms is
12/2
wire?

No matter what attachment method you use with a standard copper-pipe
J-pole, you must "match" it by adjusting the positions at which the
hot and grounded side of the coax are connected to the copper pipes.
As a rule of thumb, moving the attachment points upwards along the
pipe causes the feedline to "see" a higher impedance. You adjust the
position until your connection is at a point where the impedance is
50
ohms, and you end up with an SWR of 1:1 or close to it.

The easiest way to get good results is to use a set of published
plans
in which the original designer has found the correct matching point,
and then reproduce the antenna as exactly as you can.

He also gave me a short cable with two pl 259 connectors to connect
between my radio and the swr meter. It was a guy at a motorola
dealer.
This cable is pretty thin and not rg8 but he said it was 50 ohms.
I plan on hooking the 20 feet from the swr to the antenna.

Probably RG-58, and it should be fine for a short run to the
SWR/power
meter.

--
Dave Platt
AE6EO
Hosting the Jade Warrior home page:
http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

What if you are using a design plan exactly with the same diameter
material but with different material, say conduit instead of copper?

If you direct connect an so connector. How do you adjust both sides? I
mean once the ground is in place it is hard to adjust the "hot" side
unless you bend the wire alot.