CFA Up-date
You have not heard from me for some time on this subject. I have been
awaiting something to report.
MF Broadcasters are still maintaining an interest in CFA Antennas, in
spite of what has been said/or not said about this antenna.
But Proof of Performance measured results outside Egypt are yet to be
publicly released.
The LB Broadcast CFA program on The Isle of Man has suffered a
set-back, with the denial of permission to build (environmental
concerns).
Robert Richer's, of CFA, Ltd (USA), CFA project in Shropshire,
England, is still waiting for Fathi Kabbary to perform his magical
touches necessary to tune and test the CFA. Ben Dawson will (it is
reported) carry out proof of performance measurements on this CFA.
The CFA Project in Santos, Brazil has come to a standstill. The
performance of the antenna (on the roof of a building with a view on
the skyline), after completing many mechanically related
modifications asked for by Kabbary, including the addition of third
cone (??) on its top, is still performing poorly [Sylvio Damiani,
reported in the March 2001 issue of AntenneX] --- but no measured
results reported.
The San Remo CFA, we had heard earlier that it was performing as
expected, is apparently producing less signal than the previously
used tower antenna at that location --- a "problem" attributed by
Kabbary to surrounding high objects on all sides and very high trees
to the north --- but again no measured results reported.
The CFA in Sidney, Australia is for sale (or will be purchased (back)
by Kabarry ??), but it is still in use, tuned as a conventional
electrically short monopole.
Meanwhile the FCC has finally granted Lawrence Behr Associates a
license (WC2XKX) to test the CFA in the USA. These tests are
authorized on three frequencies in North Carolina.
Finally a success (??) story. Brian Stewart has reported that the CFA
in Barnis, Egypt proves that CFA antennas work, since this ground
mounted CFA shows a high degree of efficiency --- but it should be
noted (my comment) that a microwave relay tower stands in the near
field, having a height that is close to a quarter wave on the
frequency used.
The CFA story continues.
But the purpose of this Technical Correspondence (TC) is tell you
that the papers presented at the IEEE BTS Symposium, Vienna, VA 27-29
September, 2000 are finally posted for reading.
The WEB site is:
Note: IEEE in caps.
Concerning our experimental measured results, we have (finally)
learned how to tune the antenna, tuned as a CFA (feed currents in
quadrature, and transmitter SWR = 1:1). This has been achieved by
using a storage oscilloscope so both current in amplitudes and phase
can be viewed simultaneously.
Have fun reading.
Regards, Jack, VE2CV
-- _____________________________________________ John S. (Jack) Belrose, PhD Cantab, VE2CV Radioscientist Emertis Radio Sciences Branch Communications Research Centre PO Box 11490 Stn. H OTTAWA ON K2H 8S2 CANADA TEL 613-998-2779 FAX 613-998-4077 e-mail <john.belrose_at_crc.ca> _____________________________________________Received on Tue Mar 06 2001 - 23:59:27 EST
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