Hi John and others,
Interesting topic.. I also agree with the j-pole. Not to bend any
eyebrows.
(I also have 300ohm 2M j-pole designs web-posted )
The only comment is the use of 300ohm twinlead for antenna construction.
300ohm twinlead comes in several different variations and the velocity
factors are all over the place. So, results vary!! I've answered my fair
share of e-mails in the past 5 years, trying to explain this problem to
other new Hams. This can really discourage someone that tries to build a
first time antenna with the wrong type wire.
Stuff to look for:
Don't use the "thick stuff": also called the "Heavy Duty" with a heavy thick
brown plactic covering. It is very difficult to cut and almost impossible
to work with.
Do not use the "foam type": with foam covering the wire, between the wire
and the outside black plastic casing.
Look for the "thin stuff": and the flatter the better.
Another thought is to move to a different construction material with a
little more consistency: 450ohm ladderline, Solid copper type.
Ref:
http://home.comcast.net/~buck0/ll_coolj.html
Hope this helps others!
73
Steve KB1DIG
"John Steffes" wrote in message
...
Hal,
Your idea using the J-Pole is probabaly the best solution.
1. No radials needed
2. Easy to match using ANY type of feedline
3. Total length is about 3/4 wavelength (about 52") including matching
section
4. Easy to contruct
We found this URL that may give you an idea regarding contruction.
http://w4zt.com/jpole/
John
Hal Rosser wrote:
If you built a dipole, then it was (most likely) not a quarter-wave -
but a
half-wave
a j-pole may be a good choice given the situation that it needs to be
'out
the window' and is uhf
or, for that matter, a coaxial half-wave dipole. (strip and fold back
1/4-wave of braid - and weatherproof it)
"WolfMan" wrote in message
t...
I'm Limited To An Antenna On The Front Of My House. Out My Window I Made
A
Simple !/4 wave Verticle Dipole. Would A 1/2 Wave Simply Be Twice The
Length, Using 462/f Mhz, And Would There Be An Advantage With A 1/2 Wave
Over a 1/4 Wave ?
Thanks
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