View Single Post
  #5   Report Post  
Old June 17th 04, 11:22 PM
Dave Platt
 
Posts: n/a
Default

In article ,
Richard Clark wrote:

maybe just similar to what is known as a
"nest of dipoles" that scanner enthusiasts have. They use different
radiating elements in parallel.


Hi Jason,

Not that at all, otherwise all of the elements would be driven, and
simple observation negates that. I've reported a similar design to
this group years ago that uses the SO-239 bulkhead connector wired up
in similar fashion: One wire extending directly from the center pin
solder tail, and another wire, parallel, soldered to any of the four
holes normally used for mounting. No need whatever for the usual
JPole tuning cap.


There's an analysis of a similar design on Cebik's web site - his
"non-standard J-pole" is a bottom-fed, non-shorted design with a
shorter-than-usual radiating section and a longer-than-usual matching
leg.

http://www.cebik.com/jp1.html

It looks to me as if the Arrow design has similar element lengths to
the one which Cebik models. The Arrow trick of using one element as
the matching leg for 2-meter and as the radiator for 440 is a slick
one.

Everyone I've spoken with who has used an Arrow 146/440 J-pole has
been very happy with it.

--
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!