Branching Out
Making the most of Cycle 23
by Peter Parker VK3YE - first appeared in Amateur Radio, February 2000
You've read about the sunspot cycle in the
text books - how it peaks approximately eleven years, and how more sunspots
mean more ionisation and better HF propagation. Well, according to the pundits,
2000 is when it all happens and Solar Cycle 23 reaches its peak. This article
tells how you can maximise your enjoyment of the coming years of high solar
activity and good HF conditions.
What to expect
More of HF will be open longer. In low
sunspot years 20, 15 and 17 metres go dead at night. When sunspots are high
these bands remain open well after dusk. 10 and 12 metres, which open only
briefly in low sunspot years, will provide international (DX) contacts almost
daily. In peak years, 20 metres becomes almost a 24-hour DX band. The skip
zones on 30 and 40 metres shorten with higher sunspots, making them reliable
for short and medium distance intra and inter-state communications.
Six metre buffs also get excited during the
high part of the cycle. Whereas you almost need to make a phone call to get a
contact on six in the low years, on high-sunspot days the band bustles with DX.
On particularly good days, the best six metre stations have contacted Europe,
while operators running as little as one watt CW into makeshift antennas have
worked into Japan.
Propagation paths change when sunspot
numbers rise. It is normal for north-south paths (eg between Australia and
Japan) to be open longer and later than east-west paths (eg to Europe or
Africa). In sunspot years, most contacts made on 10 and 15 metres tend to be
with Asian stations. However as the bands improve, a wider variety of
locations, such as Europe and North America become workable on these bands.
Sunspot cycles rise faster than they fall.
In an eleven year cycle, it may take four years to reach the top from the
trough of the previous cycle, and six or seven years to get to the bottom from
the top. This is good news as it means that though this cycle is expected to
peak in a few months time, excellent HF conditions will remain for about the
next three years. The graph below shows observed and predicted sunspot numbers for
Cycle 23. See the IPS webpage for updates
on the progress of the cycle.
High solar activity is not all fun and games
- conditions can be very volatile. When sunspot numbers are high, solar flares
become more frequent. After a severe solar flare the bands may go dead, and you
may wonder if your rig still has an antenna connected to it.
Preparing for the coming cycle
When conditions are good, and you're on the
right frequency at the right time, almost anyone can work DX. However, the
higher HF bands are more fickle than bands such as eighty, two metres and
seventy centimetres. Follow the four steps below to maximise your success.
Step One - Obtain information about solar
activity and DX propagation.
Many amateurs enjoy working anyone anywhere.
They might be testing a new antenna, seeing how far their low-powered signal
will go, or just enjoy chatting to people. For these people, planning their
operating is often merely a matter of tuning around and finding a band that's
open.
Others specialise in working a particular
part of the world, perhaps to gain points for an award, for a DX contest or to
practice a language. For these people, success requires a more rigorous
approach.
The first step is to find out the right
frequencies and times for contacts to a particular location. Such information
is provided in the prediction charts elsewhere in this magazine. Propagation charts
are only a guide as conditions vary from day to day - one day, signals might
peak at 6pm, the next day they might reach their strongest at 7pm.
Updates on solar activity are given on the
WWV time and signal station. These are broadcast at 18 minutes past the hour on
2.5, 5, 10, 15 and 20 MHz. Near real-time propagation information also provided
on various websites, some of which provide maps showing maximum useable
frequencies by region and the progress of the 'twilight zone' around the globe.
A search on 'Cycle 23', 'sunspots' or 'radio propagation' should reveal plenty
of sites on the topic.
Computers are powerful tools for radio
propagation forecasting and analysis. Programs that provide details of likely
propagation given a particular set of solar conditions are available. A good
way of testing them is to make use of the worldwide network of International
Beacon Project (IBP) beacons on the higher HF amateur bands. IBP beacons share
a single frequency on each band and are time-sequenced so that only one is
transmitting at any given time. They transmit on 14.100, 18.110, 21.150, 24.930
and 28.200 MHz. IBP beacons initially identify at 100 watts and then drop power
to 10 watts, 1 watt and then 100 milliwatts - a useful feature that allows one
to quickly check band conditions.
Step Two - Erect antennas for the higher HF
bands.
You'd be surprised how many amateurs own
do-everything multiband transceivers, but miss out on many bands for the want
of five dollars' worth of wire stuck up in the air. Dipoles, ground planes or
half-wave verticals will get you started and can provide worldwide contacts at
times.
If you like a particular band, erect a
directive gain antenna, such as a yagi or quad. Such antennas can either be
rotatable (usually made of telescoping aluminium tubing) or fixed direction,
with wire elements slung between well-located poles or trees. Gain antennas
have the following advantages compared to dipoles and verticals.
- Clearer reception. Gain
antennas can usually be rotated to null out interfering stations coming
from the rear or side.
- Stronger signals at the other end. A station using a three element yagi and a 100
watt transmitter should sound as strong as a 400 watt transmitter feeding
a half-wave dipole.
- Longer operating periods possible. A low gain antenna will provide DX contacts in
the middle of an opening. However, at the beginning or end of openings,
people with dipoles often find it hard to make themselves heard. A gain
antenna allows contacts during these marginal conditions, thus extending
the period that stations can be worked.
- A greater variety of stations become workable. The author has found that when using low power
and simple antennas the majority of DX stations worked had quite large
antennas, such as five or six element yagis. As conditions improved, a
more contacts were with people using smaller antennas, such as two or
three element yagis. Improving your antennas makes reception easier and
therefore aids contact with stations who may be mobile or running low
power.
Not everyone can erect towers stacked with
beams. Even if you're restricted to verticals or dipoles, there's plenty of
things that you can do to improve your signal at the other end. These include:
- Raise the height of your dipole. Most radiation from low dipoles goes straight up, rather than
towards the horizon. This is fine for local contacts on 80 and 40 metres,
but poor for long distances. Greater antenna height allows more radiation
at angles close to the horizon, permitting longer distances to be covered.
Increasing you antenna's height from five to ten or (better still) fifteen
metres is one of the most cost-effective improvements to your station that
can be made.
- Use elevated verticals with above-ground radials. Vertical antennas with buried radials require
many radials to perform efficiently, especially in areas of poor soil
conductivity. Installing vertical antennas on a support pole several
metres high and using above-ground radials allows good performance with
only a few radials.
- Use verticals that are less dependent on ground systems. If installing radials is difficult, consider a
half-wave vertical. Compared to quarter-wave ground plane antennas,
half-wave vertical antennas (such as the famous CB Station Master antenna)
can be highly efficient with a minimal ground system. The extra height
will help too!
- Consider fixed-wire beams.
If you're mainly interested in one direction, wire beams strung up in
trees can provide low-profile antennas capable of top performance. A
two-element wire yagi can be slung between four well-placed trees, while a
two element quad for ten or fifteen metres can be concealed in the canopy
of a single tree.
- When all else fails, operate portable. Most Australians have ready access to open
spaces, whether in the hills or by the coast. A simple inverted-vee or
vertical antenna can yield outstanding results, especially if installed in
an over-water location, such as on a boat or pier.
Step Three - Know your station
Once you have some antennas and know the right
times and frequencies to try, the next step is to assess if your station is
capable of exploiting the propagation available. A full assessment is beyond
the scope of this article, as it requires an advanced understanding of wave
propagation, antenna gain, radiation angles and receiver noise. However, the
following example should succeed in explaining the desirability of having
reasonable expectations based on what propagation can provide.
After looking at propagation charts or a
computer program you may conclude that 40 metres may currently be open to the
US. Turning on your receiver may reveal strong signals from North America.
However a full assessment (as mentioned above) is likely to disclose that
expecting frequent North American contacts with five watts and a low dipole is
unrealistic. You would get very disappointed very quickly if you were expecting
regular contacts with North America using that dipole.
On the other hand, if your ambition is
simply to span the Pacific occasionally with low power and are using an
efficient, low-angle antenna (such as a high dipole or vertical) there is no
reason why you cannot achieve your aim with a little persistence. The lesson
here is to set reasonable objectives, and design your station so it can meet
them.
Step Four - Polish your operating technique
You may have a good station and antenna
installation, but will not be able to use it to its full potential unless you
can properly adjust and operate your equipment.
- Set your transceiver up correctly. Excessive microphone gain can cause
over-modulation and interference to other band users. Poor earthing gives
rise to RF feedback, microphones that zap your lips and rough-sounding
audio. A quarter wavelength wire connected to the transceiver's metal case
usually fixes these problems where a proper RF earth cannot be installed.
Speech processing can raise the intelligibility of your transmission when
signals are weak, but too much causes distortion and excessive pick-up of
other noises in the shack. A power supply that is too small or poorly
regulated causes 'FMing' on SSB and chirp on Morse.
People prefer to answer calls from stations
with clean signals, and quality signals penetrate through interference better.
See your transceiver's instruction manual for more detailed guidance on
adjusting your particular rig.
- Tune around the bands for DX. You'll hear nothing if you're not listening. To learn which bands
are open to which places, spend 20 or 30 minutes at various times of the
day to tune across the various bands. Note the locations of stations heard
on each band and correlate this to the time of day. You don't always have
to wait for the station to give his exact location - listening for the
callsign prefix and looking up the country in the WIA Yearbook is usually
good enough.
After a while you will observe both certain
consistent patterns of propagation (eg many strong European stations in the
late afternoons on 20 metres) and significant day-to-day differences in
conditions. Don't overlook the IBP beacon frequencies (given earlier) in case
there is propagation but no activity.
- Use various means to gain contacts. There are several ways to get contacts. These
include calling CQ, answering someone else's CQ, or calling one of the
stations involved in a contact that has just finished ('tail-ending'). The
latter is particularly effective as you know the band is open and there is
a good probability that someone is still listening. When tail-ending, the
main thing to watch is to ensure that all parties have properly signed
before you call. This is not always easy - sometimes people take five
minutes to say 73, may sign off several times and do not always end their
contacts cleanly. Count to four or five, and if nothing heard, make your
call.
One benefit of being in Australia is that
when working DX (eg Europe, Japan, North America), there's many more of them
than of us. This works to our advantage in several ways. Firstly, it makes
overseas stations eager to work VK. Secondly, if you are calling DX stations
(whether answering a CQ or tail-ending), the competition from other VKs/ZLs who
may also be calling is relatively light.
- Know when to call people
I have often heard people whose signals should have been heard, but have
missed out on contacts because they timed their calls poorly. They may
have been calling while a previous contact was still signing off, or
called at the same time as several others. If dozens of stations are
calling a particular station, it is likely that he is unable to pick out
an individual callsign. It can sometimes be worthwhile to insert your call
as soon as the melee dies down. With any luck the DX station will hear
you, not because you were the strongest, but because you timed your call
best. At other times, DX stations may be tuning up or testing. It
sometimes pays to give them a quick call before they call CQ and the
multitudes find them. Timing is very important. It can't be taught, but
can be learned through regular on-air activity, and observing what works
and what doesn't.
- Put out calls if the band appears dead. People will not know if the band is open if no
one is using it. It's up to you to activate the band by putting out a
call. These days this doesn't mean endlessly pounding the key or calling
into a microphone. Cassette recorders, digital voice recorders and even
computers can be set up to call CQ automatically, especially if your rig
has VOX (voice operated transmit) facilities Always be in attendance to
answer any calls - there's nothing worse than trying to answer someone's
unattended CQ caller!
Should I upgrade?
If you have a Novice Limited licence, Cycle
23 will be a non-event if you don't upgrade to at least Novice. If you don't
act now, you'll need to wait another decade before you can take advantage of
the next sunspot peak.
Limited licencees are a little better off.
They have six metres all modes and ten metres FM. However, as the saying goes,
six metres is not just a band - it's a way of life. You can spend days by the
transceiver, and not hear a thing. Then after returning from a short absence,
you're told you missed the biggest, greatest six metre opening there ever was!
Six is like that - it waits for no one. 29 MHz FM is also fickle, and is
markedly inferior to SSB when signals are weak.
To really take advantage of Cycle 23, Novice
is an absolute minimum grade you should aim at. Intermediate grade is also
worthwhile, because of the extra frequencies it provides on the 3.5, 21, 28 and
50 MHz bands.
As conditions decline, around 2002-2003, ten
and fifteen metres will open less time each day. Twenty metres will once again
become the main DX band. An unrestricted licence is particularly desirable in
intermediate and low sunspot years because of the 20 and 40 metre privileges it
provides. Access to the 12, 17 and 30 metre bands is also useful, especially
when 20 metres is very crowded.
If you've just completed licence study, it
is desirable to obtain your AOCP as soon as possible, while the knowledge and
Morse is still fresh. If you've had a Novice or Intermediate licence for some
time, and have to make a choice between studying and operating, I would suggest
you enjoy the next couple of years on the air and obtain your Unrestricted when
conditions start to decline and the middle and lower HF bands become more
useful.
Conclusion
This article has, I hope, provided an
introduction of what to expect from Cycle 23 and how you can take advantage of
it. Many amateurs' most memorable contacts are made in high sunspot years such
as this one. Prepare your station and make sure you get a fair slice of the
action in the years ahead.
References
and further reading
1. Weiss, A The Joy of QRP - Strategy for
Success, Milliwatt Publications, 1984
2. ARRL Handbook, various editions.
3. Moxon, L HF Antennas for All Locations,
RSGB, 1982
4. ARRL's Wire Antenna Classics,
ARRL, 1999
5. IPS website: http://www.ips.gov.au
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This page was produced by Peter Parker VK3YE parkerp@NOSPAMalphalink.com.au. Material may be copied for personal or non-profit use only.