Operating from tall buildings
A few amateurs are lucky enough to live in
good locations and always seem to have the best VHF/UHF signals. They can
always hear people you can't and hit repeaters you've never heard of.
How would you like to be one of the
biggest signals in your city for a day, or even a couple of hours? Well you
can, just by taking your equipment to a good spot. At a good location you can
compensate for your 30 watt VHF/UHF power limit and restricted antennas. For a
short time you'll get out as well as the "big guns".
One of the best places to go is the top of a
tall building in the middle of the city. This article provides some tips on how
you can go 'skyscraper portable' and successfully work the VHF/UHF bands.
Places
Some cities have tall buildings with public
viewing platforms. Others have viewing platforms that only open on special
occasions. There are also cities which have a viewing structure other than an
office building fairly close to the CBD.
Even where your city has no buildings with
public viewing platforms, do not discount the possibility of gaining access to
the roof of a tall building. This would be a great project for your club for
next year's John Moyle Field Day.
The following is a listing of some operating
spots available in major Australian cities. Source information came from
personal observation, other amateurs, state tourism centres and building staff.
Adelaide
Adelaide lacks the tall buildings found in
other Australian capital cities. However the Adelaide Hills are fairly close to
the city and offer good opportunities for VHF DX.
Brisbane
The Queensland Government Travel Centre
advised that there are no tall city buildings that have viewing decks
accessible to the public.
Canberra
Canberra also has no really tall city
buildings. The nearby Telstra Tower includes a public observation deck that
provides good views from Black Mountain. The city is surrounded by hills that
offer good opportunities for microwave enthusiasts and VHF/UHF DXers. Because
of the lack of local VHF/UHF FM activity, SSB operation on Saturday and Sunday
mornings is likely to provide the best opportunities for long-distance
contacts.
Melbourne
The Rialto Tower allows public access to its
55th floor for $7.50. A good take-off exists in all directions. The tower is
open until 10:00pm (11:00 pm Fridays and Saturdays). Reasonable food is
available from the cafe near the viewing deck.
Though it's not nearly as high as the
Rialto, Tony VK3JED has had good results from the Westgate Bridge while
operating mobile on various frequencies between 144 and 1300 MHz. The main
problem with this site is that the operating time is limited to approximately
two minutes (depending on traffic conditions). Other sites that Tony says are
worthwhile include Glen Waverley (alongside the Police Academy), Bundoora, just
north of LaTrobe University, and Doncaster Shoppingtown (in the top level car
park).
Perth
The Western Australian Tourism Centre
advised that Perth has no buildings which have observations decks that are
regularly open to members of the public. However, good views are available from
the top of the DNA spiral look-out in Kings Park. South-West repeaters are
accessible from this site, but signals will usually be marginal with two watts
unless you use a small yagi or quad antenna.
Sydney
Sydney's AMP Tower (formerly known as
Centrepoint Tower) has a public observation deck 305 metres above street level.
It is open each day until 10:30pm (11:30pm Saturdays). Full admission costs
$10.00, but pensioners and children pay much less.
Equipment
The equipment used need not be any different
from that used from any other spot where mains power is not available. The only
thing to watch is the strength of your transceiver's front-end - you are just
hundreds of metres from high-power pager transmitters and your receiver will
need to withstand the onslaught of kilowatts of RF in the area. The author has
found that the all-mode Yaesu FT290R MK1, which is not the most sensitive of
radios, to be a good transceiver to use in high-RF areas. Directional antennas
and/or horizontal polarisation can also assist in keeping pagers out of your
receiver.
Other equipment you should take is a callbook
with a current repeater and beacon list, pen, paper, and sufficient battery
capacity to last your expected time aloft. Where the building is darkened at
night, a small torch to read the callbook and any notes you write is handy.
Headphones or earphones that don't make you look like a Martian are also
desirable to prevent other visitors from hearing your contacts.
Antennas
This is a question of how much attention you
wish to draw to yourself. A small hand-held yagi or quad would obviously be
ideal, but has a visual impact that cannot be ignored in a small space. There
is also the risk of detuning your antenna by adding the odd eye ball along the
way if the ends of your elements are rigid and pointed. The author has taken a
small yagi on two occasions. In both cases it was not used because of its
visibility and the number of people present.
A quarter wavelength whip for two metres and
a 5/8 wavelength whip on 70 centimetres are not too conspicuous and are
suggested as a sensible compromise between antenna gain and visibility.
Horizontal antennas are harder to arrange.
The author has always tilted the vertical antenna on the transceiver when using
a vertical antenna. However, the serious SSB operator should consider building
a halo for the purpose.
Batteries
Having taken the trouble of travelling to
the operating spot (and paid to get in), you will want to be able to operate as
long as you possibly can. This means taking your handheld's biggest battery
pack, perhaps with a fully-charged spare for good measure. A 12 volt 6 to 7
amp-hour sealed lead acid battery will provide reliable operation for hours at
a time, especially if you indulge in long ragchews between contest contacts.
Operating time can also be extended by selecting the low power setting on your
transceiver - 1 watt is plenty for most metropolitan-wide contacts, and quite
long distances can be spanned with just a few milliwatts of transmit power.
Attitude of building staff
Provided you use modest antennas, refrain
from shouting into microphones and flooding the building with FM receiver hiss,
you will generally find that staff will be courteous and tolerant of your
transmitting activities.
However, it's not a good idea to stay in the
same spot for a long time - you may be considered a security risk and may be
asked to show the contents of your bag. Moving at least every 5-10 minutes also
lets other people enjoy your view and allows you to try for contacts or
repeaters in other directions.
Getting contacts
To get a worthwhile number of contacts, you
will need to generate activity yourself.
If you are operating from a large city, it
should be easy to work people throughout the metropolitan area and beyond with
a few watts. However, don't assume that contacts will come easily simply by
calling CQ on 146.500 MHz just because the Callbook lists it as the FM simplex
calling frequency. You can have the world's biggest signal on 146.500 MHz but
sometimes not get an answer.
The reason for this is that Australian
hamdom is best understood as being a large number of disparate tribes, each
inhabiting their own simplex frequencies or repeaters. The best way to make
more contacts is to tune around the obscure simplex frequencies in the week
prior to your expedition and find out who uses which frequencies. Then put out
calls on these frequencies as well as the recognised calling channels when
you're portable. Also do not neglect that some country repeaters will be
workable from your lofty position. Your transceiver's repeater reverse
facilities can be used to determine if you could attempt simplex operation with
stations you work.
Another way to get more contacts is to
generate awareness of what you are doing and when you will do it. This may
include mentioning it at radio club meetings, putting a message on the
aus.radio.amateur.misc Internet newsgroup, mentioning it on the VK-VHF-DX
reflector and placing a bulletin on packet radio. It's not every day that local
amateurs can work their city's tallest building, and you will find that your
activities will generate interest among local hams, which of course means more
contacts for you.
Contests
Contests with a VHF section are excellent
times to go portable from a tall building. This is because they bring out
people that are seldom on air at other times.
There are huge variations in contest
activity between capital cities. For example, in Perth there is not much
interest in the Spring and Summer VHF/UHF Field Days, but the Remembrance Day
contest brings dozens of normally inactive operators to the VHF/UHF bands. In
contrast, station logs confirm that VHF/UHF RD contest activity is almost
unknown in Sydney, despite that city's larger population. Like Perth, Melbourne
also enjoys high RD contest activity on VHF. The other cities fall in between
these extremes. The Remembrance Day contest is held each August - this year's
is scheduled for the weekend of August 14-15. It's the best opportunity you'll
get to work many stations in a short time from a high place on the VHF and UHF
bands. The RD rules will appear in Amateur Radio for either July or
August.
Many amateurs don't like contests or say
that they have 'been there, done that' and will not submit a log. However, it's
usually possible to wring numbers out of these people, and get points that
others miss. You can work these people by calling them on 'their' simplex
frequencies (found out pre-contest). As well you should emphasise in your
publicity efforts that your activity is a rare opportunity for stations to
'work the city's tallest building' only casually mentioning that you are there
as part of a contest operation. If you are a lot of people's first contact (ie
many 599001 numbers in your log) you know that you have been successful in
generating this type of activity for yourself. With any luck the stations you work
this year will be more active in the contest next year.
Conclusion
The author has operated portable from
Melbourne's Rialto Tower during the last three Australian VHF/UHF contests.
Distances approaching 150 kilometres have been spanned with 2.5 watts FM to a
simple whip antenna. Operating from tall buildings is a great way to exploit
the capabilities of your equipment to the maximum and make contacts not
possible from your home station.
This article appeared in Amateur Radio June 1999. No updates have been made and it appears solely for historical interest.
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