[Antennas] J-Pole

Tue Sep 28 22:03:42 EDT 2004

> I have a homebrew 2M/70CM J-pole 50 ft. in the air for use with a 5W HT. 
> Am currently using RG-213 for feedline. i am wondering if it is worth 
> the effort to switch the feed to ladder line, and if so how to do it?

 I was told by a chum that he was taught: (at HAM school)
 "you can't use 300 Ohm `twin lead' on VHF"
 I had to remind him: 300 Ohm `twin lead' was INVENTED for
VHF television.
 Use 1/4 wl stubs like the bottom third of a "J" pole and connect
the coax as though it was a "J" pole, connect the high impedance
balanced line across the two copper tubes about 1/3 the way from
the shorted end, use real small aviation hose bands as clamps and
slide two Hi-Z balanced wire ends up and down for the best match.
 You can solder under the SS hose bands with a propane torch if
you wish, then you should be able to remove them for later use on
the next one you make.
 You can use two of these impedance matchers, top and bottom or
you can connect the Hi-Z balanced wire directly to some antennas
at the top end.
-- 
 73 (= Best Regards) de: Ron ka4inm at tampabay.rr.com
 100% LINUX, since July, 1997 SENT Time and Date are UTC
 Visit my HAM Web SITE at: http://www.qsl.net/ka4inm