The best possibility I can think of is that the impedance presented by
the HT case/human hand and body is considerably lower than the impedance
presented by the wire. If this is true, the body would get most of the
current, and the quarter wave wire wouldn't get enough to make a
significant difference to the total field. Another possibility is that
coupling between the body and the quarter wave wire reduces the wire's
current to a low level.
I recommend that anyone interested in HT antennas take a look at "An
Investigation of 2-Meter HT Antenna Performance" by Ken Pierpont, KF4OW
and Ed Brummer, W4RTZ, in the _ARRL Antenna Compendium_, Vol. 4. It
looks to me like a good job of making some comparisons between antenna
types. Unfortunately, they didn't try a single quarter wavelength wire,
although they did try a 4-wire ground plane, and found a significant
effect from it.
Roy Lewallen, W7EL
Ed Senior wrote:
Hi Scott -
This is an interesting question.
A device like this SHOULD work, as the typical HT suffers tremendously
from the lack of a "counterpoise." One only has to see how the typical
end-fed half-wave HT antenna completely destroys a quarter-wave HT
antenna, to get the point.
HOWEVER: I have tried using a quarter-wave stub (like the rattail),
connected directly to the coax connector... and it seems to do almost
NO good. I'm frankly at a loss to explain this.
I'm convinced that some of the short duckies are tuned to expect
the counterpoise effect of the little HT chassis, capacitively coupled
to a human body; so maybe there's a reason why they wouldn't
benefit from a quarter-wave stub. But I have no theory why a full-sized
quarter-wave antenna doesn't perk up more when a stub is added.
Maybe some of our computer modeling fans can propose an explanation.
73, Ed W6LOL
"Scott Drumm" wrote in message
...
Anyone tried this out on their HT? Does it work as advertised?
http://rattailantenna.com/
I was thinking about buying one for my IC-T22A. I've replaced the stock
rubber duck w/ a Smiley SLD-2 12" 5/8 antenna, but want to see if I can
reach some more distant stations.
Thanks for the help!
Scott Drumm
N3XFD