The
following notes are based on observations made over 30+ years of QRP operation
from locations throughout Australia.
2200 and 630 metres
Allocations around the world vary. Australia has allocations around 136 and 472 kHz.
Antenna efficiency is obviously key at these frequencies, although groundwave propagation can provide excellent coverage, in some cases offsetting losses
due to lower antenna efficiency compared to (for example) 160 metres.
160 metres
Can be quite rewarding, especially if there are many
close-by stations that can easily be worked on QRP. The main
difficulties for urban dwellers are the antenna requirements and the high noise
level on the band.Nevertheless, SSB contacts of 500km have been
had with 10 watts to an indoor antenna on 160. During the day, expect 10
to 30km with QRP – more with a good antenna. CW is most used for
DX, SSB for interstate working, and AM for local nets. During the
evenings a tune across 160m will usually find one or two SSB contacts in
progress. CW activity is just above 1.800 MHz, with 1.825 – 1.835
MHz being popular with North Americans. In Melbourne there is considerable
AM activity most mornings on 1.825 MHz, and a 1-watt rig can be successful if you
live in the eastern suburbs, where most operators live. Look out for cheap 1.843 MHz
crystals and build your AM rig around that. Listen before building - where SSB is more
common a frequency-agile DSB rig will be more successful than an AM rig. If you have
an efficient antenna or can operate portable by the sea, transpacific CW
contacts are possible with QRP.
160 metres is an immensely challenging
band for the QRPer, but the distance and variety of stations easily workable is
less than on some of the higher bands. Space for antennas, noise levels
and local activity are the major considerations for those seeking to become
active on this band. Unless you live in an area with considerable AM activity, beginners are advised to equip themselves for
another band, such as 40 or 80 metres before trying 160.
80 metres
A popular band for homebrew QRP equipment.
Almost all single-band kits developed in Australia have been on 80
metres. QRP scrambles and nets use 80 metres as the primary band. If
you wish to work other VK QRPers, 80 is probably your best bet.Antenna
space requirements are more relaxed than for 160m, though getting a good
antenna up for 80 can still be a battle. This is a challenge in itself -
working ZL with QRP to an 1.5 metre indoor magnetic loop is rare, but a great
achievement when it happens. 3.58 and 3.68 MHz ceramic resonators make
frequency agility easy to achieve with very simple equipment, though properly
built VFOs are also stable on this band. 80 is good for reliable night
time QRP contacts up to about 500 km, with occasional contacts up to 3000 km
being possible. Like 160 metres though, static from thunderstorms
can spoil reception. Further distance DX contacts are
possible but you need to be in the right place, in the right time, with the
right antenna to work any of it. Daytime QRP contacts on 80 metres are
possible, but normally require prior arrangement, due to low use of the band at
this time.
A good choice for the operator wishing to
make local and medium distance QRP contacts during the evenings. The large
antenna required, noisiness of the band and lack of daytime activity are the
main disadvantages of 80 metres.
40 metres
The author's favourite for contacts within
south-eastern Australia (ie 300 - 1000km). The low noise level on 40 makes QRP to QRP
working more pleasant than on 80 metres. The feasibility of daytime
working is another plus, especially for portable operating. Homebrew CW
and DSB equipment work well on this band and can provide many solid
contacts. 40 is almost always open during the day over distances of
200 to 1000km, with closer-in contacts possible in high sunspot years.
There is usually someone on, though for the QRPer wishing to make random
contacts during the day, SSB or DSB capability in addition to CW is an
advantage. You'll hear CW activity most afternoons. The response rate to CQ calls is generally
good (better than 80 metres in my opinion), but there can still sometimes be long
gaps between answers. If operating portable, take a good book to read
between calls and consider building an automatic CQ caller.
Dawn and dusk bring longer distance contacts
– from south-east Australia, VK6 and ZL are workable, even with average
antennas. You will also hear signals from North America, Japan and Europe
at this time, especially on CW. Often these signals are tantalisingly
strong. Yet, 95% of the time when you call you won't be heard; the
station will have recommenced their CQing or made contact with someone
else. That doesn't mean that you should never call DX stations on
40 metres – if conditions are just right, you will make contact – even with
three watts. Treat 40 metre DX as you'd treat a lottery – it's good to
win, but do not be disappointed if you don't if all you've got are average
antennas. For regular QRP DX on 40 metres an efficient low-angle antenna
is a must – an average dipole 5 - 10 metres above ground will spray most of the
signal straight up – fine for local contacts, but useless for DX.
Advice on suitable antennas for 40 metre DXing is provided in ON4UN's Low Band
DX book.
An excellent band capable of
providing a wide variety of local and medium-distance contacts. Small
antennas, reasonable activity, low noise levels, daytime propagation and
comparative ease of building equipment all make 40 metres an excellent choice
for the QRP newcomer.
30 metres
Overseas QRP publications rave about the DX potential
of 10 MHz, but I've only experienced this occasionally. The band exhibits features of
both 40 and 20 metres. Like 40 metres, long-haul DX on 30m is
difficult. Like 20 metres, 30 metres exhibits a large skip-zone that puts
much of the VK amateur population out of range if operating from south-eastern
Australia. VK activity on 30 is lower than 40 and 20, making random
contacts harder than on other bands. 30 metres is at its best for
contacts of between about 1000 and 3000 km, especially when communicating with
mobile stations. During solar peak years, 10 MHz is superior to 7 MHz for
daytime contacts between Melbourne and Sydney. ZL and VK6 are also well
within reach for the 10 MHz QRP operator in south-eastern Australia.
Longer distances are certainly possible, but only with a very good antenna.
30 metres is excellent for medium distance contacts within VK-ZL. DX is difficult
but not impossible.
20 metres
Welcome to the major QRP DX band! It can
support DX activity during both high and low sunspot years. Of all the
bands reviewed, 20 metres is capable of providing the widest variety of
contacts, from about 1000 km to the furthest corner of the globe.
It's an excellent choice for operators outside south-east Australia, where the
lower density of the local amateur population sometimes makes contacts on 160,
80 and 40 metres hard to come by.
CW is an excellent mode for the 20
metre QRPer. When conditions are good listen near 14.060 MHz for overseas
QRPers – for them VK/ZL would be a fairly rare catch. The pace of operating
is faster than on the lower bands, and a CW receiving speed of at least 20 wpm
or better is an advantage. However, unless signals are strong, QRPers
will obtain best results by keeping transmitting speed to the 15 - 20 wpm
range.
PSK-31 is a narrow-bandwidth
mode (around 14.070 MHz) highly effective with QRP. This computer-based mode allows solid DX
contacts that would not be possible with SSB. QRP slow-scan TV (around 14.230 MHz) is also effective around Australia, even during low sunspot years. Live SSTV cams allow you to monitor your transmitted picture from around the world even if no stations are active to make a two-way contact. Software for both PSK-31 and SSTV is freely available and transmission only requires a very simple interface box between transceiver and computer.
Despite the 'kilowatt alley' reputation, QRP SSB on 20 metres is rewarding. In low sunspot years these will be up to about 3000 kilometres, but worldwide contacts are possible when conditions are good. In all cases contacts come easier if operating portable from a good location overlooking water.
20 metre equipment is somewhat more complex
to build than gear for the lower bands. Receiver sensitivity and
selectivity need to be better than on the lower bands, and either a VXO or
pre-mix VFO may be required for good frequency stability. 20 metres is
the lowest band at which gain antennas become a reasonable proposition.
For portable operation half-wave verticals and full-wave loops are both capable
of good DX results.
The ultimate band for the QRPer wishing
to work DX. Also effective for longer-distance contacts within VK.
Portable operation on 20 metres is highly recommended, with DX contacts
almost every time.
17 metres
Some of the author's best QRP experiences have been
on 18 MHz during high sunspot years. When conditions are good, QRP can be like QRO, with Europeans
stations lining up to make contact, and sometimes having to handle several
stations calling. Milliwatts seem to do better on this band than 20 metres, provided that the band is properly open (there are many times when it isn't). Like 30 and 12 metres, contesting has been
barred from 17 metres, making the band particularly useful for casual operating
during a major international contest. VXO CW QRP rigs are quite practical
on 17m by using a 27.125 or 27.145 MHz ex-CB crystal on its 9 MHz fundamental
and then doubling.
A relaxed alternative to 20 metres, though less consistently open.
15 metres
Capable of excellent QRP results, though more fickle
than 20 and 17 metres. Often open on north-south paths (eg to JA) when 10
metres is closed and 20 metres is open to somewhere else. Again a
VXO CW transmitter would be an excellent project for the band.
Excellent for working into Japan with
less crowding than 20m.
12 metres
A cross between 10 and 15 metres. The author
has had little QRP experience on this band.
Possibly the least useful HF band for QRP,
but can still yield good contacts when conditions are right.
10 metres
Fun but fickle. Opens in high
sunspot years. But even then there are many times when 20 and 17 metres
provide better DX results. Sporadic-E provides extremely strong
interstate and ZL openings in midsummer and midwinter at any phase of the
sunspot cycle. Most local activity is SSB. CW gets most use
for DX working.
FM simplex and repeater activity occurs
above 29 MHz, but fading and phase distortion affects FM more severely than it
does SSB. This makes 10 metres FM QRP both exhilarating and frustrating. Enjoy the
good propagation on FM, but otherwise stick to CW/SSB unless you're only interested
in local contacts, are near a 10 metre FM repeater or have excellent (beam)
antennas.
Much QRP(ish) equipment on the band is CB
radios converted from 27 MHz or transceivers such as the Yaesu FT-817.
With such gear, pedestrian and bicycle mobile SSB is quite practical,
particularly during a sporadic-E opening.
Capable of high-quality contacts when
conditions are right. Very quiet when they're not.
6 metres
Capable of once-in-a-lifetime milliwatt QRP DX
achievements if you're there at the right time. A proper antenna
for the band is not even necessary if conditions are good encough! DX is
very dependent on the sunspot cycle, but Sporadic-E can provide
interstate contacts. CW finds most use for DXing. Most
SSBers are DXers – when there's no DX, generally there's no activity. It
has been said that you need to make a phone call to arrange a contact on 6m
SSB. This is despite the good local propagation characteristics of six
metres.
There is also FM activity on six metres.
A milliwatt transmitter for six metres FM is easy to build and is a great
project if you're near a repeater, although activity is much lower than two metres. Interstate
Sporadic-E propagation also works well for FM, with 52.525 MHz coming alive
during mid-summer openings.
The band for the operator seeking the
ultimate DX achievement, and is willing to sit by his radio all day waiting for
it to happen. However, there can be days if not months between contacts in most parts of Australia. Those seeking more regular activity should
look elsewhere. For local contacts, though, six is an excellent
alternative to two metres.
2 metres
CW/SSB is good for local and extended local contacts
when 160/80/40m is noisy or if there are severe antenna space
constraints. 200km or more is quite achievable from an elevated
location.
In south-east Australia there is aircraft enhancement activity
on Saturday and Sunday mornings. There are also SSB nets during the week
and VHF/UHF Field Days in Winter, Spring and Summer, which are excellent times to
try QRP. Other countries have similar activity nights and contests.
CW finds most use for weak-signal DX or
auroral propagation, which badly distorts SSB signals.
Computer-based slow-speed digital modes can provide amazing distances, even with milliwatts.
A popular activity
is chasing grid squares, based on latitude and longitude. Operators
often travel to unpopulated squares to give others the chance to working
them.
Tropospheric ducting can allow hundreds or
even thousands of kilometres to be covered with QRP, especially on over-water
paths such as Bass Strait and Great Australian Bight and equivalents in other countries such as the
Gulf of Mexico. Sporadic-E also occurs, but is much less frequent than on 6 metres.
QRP is also effective for satellite
operating, especially when using low-earth orbiting birds. Depending on
the satellite, FM or SSB/CW are the modes to use. See the AMSAT page for the latest information on
amateur satellites.
Provides quality local communications
(especially while mobile) that is largely unaffected by static or varying
propagation. Longer distances are possible on SSB/CW/digital modes and through
satellites. However can be quiet in country areas.
70 centimetres
Similar to two metres, but less activity and generally
shorter distances possible. Many contacts are pre-arranged from 2 metres.Lower noise levels, ability toconstruct small but high-gain antennas and
propagation characteristics from inside trains are all advantages of
70cm. Amateur satellites also operate on 70cm.
Higher
Because of the difficulty and expense of generating
appreciable amounts of RF power at these frequencies, most activity on these
frequencies is QRP or near QRP power levels. There are email lists and Facebook groups for those interested in these frequencies.
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