info on the K9AY loop
Listening test and other observations
How to make your own K9AY
The importance of good ground
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of the KPAY
loops working as four
By Johan Bodin, SM6LKM
K9AY web group, August 22, 2000
I think I have invented a way to make two loops appear as four loops...
If the two loops of an ordinary K9AY is connected in series, the
resulting two-turn loop will act as a single loop at 45 degrees
to the physical loops (law of symmetry). If the polarity of one
of the loops is reversed (i.e. swapping the wires), the direction
will change 90 degrees giving a +/-45 degree shift from the usual
I installed a new K9AY today, 8m high with lower corners +/-6m from
the mast at 2m height.
The termination is a selected ORP-12 illuminated by four
bright LEDs (Rmin = 23 ohms).
The transformer is a Philips 25mm toroid made of 3F3 material,
45 turns primary, 15 turns secondary.
The relay box has two extra relays that connect the E-W loop
in series/anti-series with the N-S loop.
The results are quite amazing!
The deepest null on some stations are achieved by selecting the
new "45 degree directions".
I don't have any four loop K9AY to compare with, but, after a few
hours of testing, I begin to think that this antenna behaves as
if it had four loops!
Most of the tests were done between 150 and 900 kHz.