SILICON CHIP
PUBLISHER'S LE'I-IER
Publisher & Editor-In-Chief
Leo Simpson, B.Bus.
Editor
Greg Swain, B.Sc.(Hons.)
Technical Staff
John Clarke, B.E.(Elec.)
Robert Flynn
Regular Contributors
Neville Williams, FIREE, VK2XV
Bryan Maher, M.E. B.Sc.
Jim Yalden, VK2YGY
Garry Cratt, VK2YBX
Jim Lawler, MTETIA
Photography
Bob Donaldson
Editorial Advisory Panel
Philip Watson, MIREE, VK2ZPW
Norman Marks
Steve Payor, B.Sc., B.E.
SILICON CHIP is published 1 2 times
a year by Silicon Chip Publications Pty Ltd . All material
copyright (c). No part of the contents of this publication may be
reproduced without prior written
consent of ttie publisher. Kitset
suppliers may not photostat articles without written permission
of the publisher.
Typesetting/makeup: Magazine
Printers Pty Ltd, Waterloo , NSW
2017 .
Printing: Macquarie Publications
Pty Ltd, Dubbo, NSW 2830.
Distribution: Network Distribution
Company.
Subscription rates are currently
$42 per year ( 1 2 issues). Outside Australia the cost is $62 per
year surface mail or $120 per
year air mail.
Liability: Devices or circuits
described in SILICON CHIP may be
covered by patents. SILICON CHIP
disclaims any liability for the infringement of such patents by the
manufacturing or selling of any
such equipment.
Address all mail to: Silicon Chip
Publications Pty Ltd, PO Box
139, Collaroy B.,each , NSW
2097 . Phone (02) 982 3935 .
ISSN 1030-2662
* Recommended and maximum
Australian price only .
2
SILICON CHIP
There's a UHF antenna
in your future
Some time ago we planned to publish a four-bay bow-tie UHF antenna. We thought it would be quite a popular project since more and
more viewers, even in the country, are now being serviced with UHF
television broadcasts. The bow-tie array we are publishing this month
has a number of desirable advantages over the more familiar long
Yagis used for UHF. First, it covers both UHF bands and it has better
discrimination against "aircraft flutter". With those thoughts in mind,
we were quite pleased to be going to press with this antenna as
featured in our article.
And that would probably have been the end of the story as far as
our January issue was concerned. However, just as we were going to
press, the Department of Transport and Communications issued stage
one of a timetable for television channel changes from the VHF to the
UHF bands. This is the long awaited announcement of the Department's plan to move television stations from the FM band, so that more
FM stations can go on the air. Most of the displaced TV stations will
have to move to the UHF (ultra high frequency) bands.
The timetable will mean far reaching changes for millions of people
around Australia. Whereas most people up till now have not felt a
pressing need to install a UHF antenna, even though some UHF services have been available, they will now have to do so. It will be mandatory, if they wish to continue watching the same programs.
Three television channels are in the FM band, 88 to 108MHz: channels 3, 4 and 5. As well, channel 5A will also be moved upwards. And a
number of translator services occupying channels elsewhere in the
VHF (very high frequency) bands will also move into the UHF bands to
make way for some of the stations moved from the FM bands.
In stage one of the timetable just released, 15 TV stations and three
translators will be moved from channels 3, 4, 5 and 5A. These moves
will be accomplished by late 1990. Stage 2, for channel changes after
1990, will be announced in the next few months. We'll publish full
details of the changes as they become available.
The changes have been decided upon after a long period of consultation with all parties in the TV broadcast industry. In the short term,
they will cause some disruption while viewers slowly make the
necessary adaptations. In the long run, we'll have a lot more FM stations which will be all to the good.
But sooner or later, many more people will be watching UHF TV
broadcasts. Which makes our UHF bow-tie array rather timely,
doesn't it?
Leo Simpson
