"Dave" wrote in
:


"Roy Lewallen" wrote in message
...
Trying to phase two antennas that close together at that frequency
range will be an educational experience at best, but more likely just
an exercise in frustration unless you have much more patience than
average. Such an array will be hyper-sensitive to everything. You
might be able to fleetingly see a null after a lot of tweaking, but I
seriously doubt you'll even get that. A tiny change in frequency,
wiggling of the whips, or even movement in the vicinity of the whips
will have a profound effect on any null you might see.

If a null from a small antenna is what you want, you'd have much
better luck with a carefully constructed and balanced ("shielded")
loop.

Roy Lewallen, W7EL

Found my copy of Joe Carr's Practical Antenna Handbook, and re-read
the section on phasing verticle antennas. I believe you. Back to
square one, which was the thought that a loop was probably my best bet
(I had come to that conclusion a while back, but forgot why.)

Did try a shielded loop once upon a time, but didn't feel it gave me
anything to look forward to. Guess I'll dig it out and try it again.
Will try shielding it with copper "tape" and see what that buys me. I
did try a piece of coax wound in a triple-turn loop to give me 2.5 or
3 uH with which to tune, with the shield cut away to expose the center
conductor for a couple inches, but didn't feel this offered anything
either. Not sure what I'll do. Poke around and try different things
until I find something that works better than the rest. Any ideas?
I'm all ears. I tried the whips because I had them on hand, and they
were easy to install. Seems I read somewhere that contrary to
conventional wisdom, the shield on a shielded loop doesn't actually
shield at all, but becomes the antenna element. Anyone know anything
about that line of thought? I obviously know nothing, and am trying
to learn. Just don't know where to focus my energies.

I made a perfecly workable little DF once on a ferrite rod, wound with a
few turns. Worked like gangbusters on the local 2 and 6mhz stuff that I
was trying to locate.



--
Dave Oldridge+
ICQ 1800667