Is K9AY loop shape
Al Merriman: I would advise you to avoid like
the plague the flattened, rectangular K9AYs that some have installed.
If you try these I suspect you will be very disappointed with
Guy Atkins: If a defining characteristic of a K9AY is its
use of crossed-X delta loops, then I would agree with Al's comments.
Maybe the rectangular, fence-mounted loops I use at home is closer
to Wellbrook's ALA 100 antenna. This is a broadbanded, rectangular
loop mounted in the vertical plane. (On DXpeditions I use the K9AY
electronics with normal crossed-X delta loops and a fiberglas central
In my home installation, I employ the K9AY control box to switch
between the E-W and N-S loops and to vary their termination resistance.
Directivity results on mediumwave has ranged from nominal to amazing.
Whatever you call it -- flattened K9AY, broadband loop, or a fluke
-- this antenna works excellently.
As Walt Salmaniw mentioned in the HCDX newsletter recently,
I indeed found performance of the rectangular loops to clearly outperform
my best-ever T2FD. (The T2FD was the 7th or 8th I've built for 90
meters, and it had a high quality commercial balun, double-shielded
Belden coax, etc.) I compared the antennas for three weeks, and
always found signal readability and s/n ratio better on the rectangular
loops. Since the K9AY control box is involved it takes some knob-twiddling
for optimum reception. The consistent superiority of the loops gave
me no reason to continue using the visually-obtrusive 100 ft. long
The other antenna I use is a 175-ft. longwire that slopes
toward ground and terminates via 500 ohms into a bentonite-enhanced
ground system (necessary due to the extremely rocky glacial soil
here). A modified I.C.E. impedance matcher is used at the feedpoint.
This antenna is oriented toward PNG/Indonesia, and moderately outperforms
the rectangular loops on tropical band PNG & Indos about 75% of
the time. When DXing other target areas and/or frequencies, the
loops are superior.
BTW, the rectangular loop system also uses the same
with single counterpoise wires running beneath each loop. (Guy
Atkins, k9ay list, July 31, 2000)