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PA3ABK > VLF 16.04.01 19:04l 59 Lines 2413 Bytes #-8733 (0) @ EU
BID : 1438-PA3ABK
Read: GUEST
Subj: Hateley CFA does't work realy?
Path: DB0ZKA<DB0SAA<DB0GPP<DB0LX<DB0RBS<DB0ROT<DB0AIS<DB0NDK<DB0ACH<PI8JOP<
PI8WFL<PI8HWB
Sent: 010416/1612Z 29528@PI8HWB.#NBW.NLD.EU [Breda] FBB7.00i $:1438-PA3ABK
From: PA3ABK@PI8HWB.#NBW.NLD.EU
To : VLF@EU
Hi,
Last sunday 15apr01, I was just turning the dial over the VLF band
146khz. With a deaf TS440 and a 10m wire I didn't expect to hear
something, but surprise, surprise I monitored a QSO on the edges of
weakness between G8RW and M0BMU.
Could copy M0BMU rather good, G8RW was bearly readeable just with some
letters above the QRM and noise.
Understood from the QSO that G8RW was working with the Hateley antenna.
A questional system what looks on paper promissing but never convienced
in its operation.
Sceptical experiments were more or less critisized because the QSO
was made on "material" in the surroundings, meaning central heating and
plumbing in the building.
Meanwhile I arrange a "ferrite" and more 'outdoor' wire to boost up the
receiver sigs on 136kHz hoping to hear both again. Unfortunately
they didn't appear anymore.
Readers not familiar with the Hately Antenna some info:
It's maybe better known as the Crossed Field Antenna/CFA.
The principle allows to build antenna's at 1/800 of it's wavelength,
which is for 146kHz quit nice, just 2,5 meters!
At the end of the 80's GM3HAT Maurice Hately published some notes in
Electronics World and Wireles World. Altough the principle was
theoritacally well understandable it would work, I never had heard anyone
working with it. (Except this weekend...)
For Dutch readers with old Electron's on the shelf: June 1989 page 285.
The principle is based on sythesizing radiowaves by direct stimulation of
the POYTING VECTOR cross product around very smal antennas. This is
achieved by suitable phased and oriented intense electric & magnetic
fields separately stimulated by different electrode systems, each fed with
half of the total power.
In it's simple form the array consists of 2 cylinders on top of each other
separated by a third (small) ring. Both top and bottom cylinder are fed with
90 degs phase shift in respect to the middle ring. The 90 degs shift can be
obtained by pieces of coax. (Like phase shift by VHF array's, need a lot of
cable for 147kHz hi...)
Anyhow, if somebody have experience with the CFA array please let me
know. It maybe worth to try it on 147kHz to keep the antenna system within
the limits of my house.... Possible you can suggest how to get along with
the 90 degs phase shift without the reel of 350m coax.
73's
Jan
PA3ABK
NNNN
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