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The exclusive amateur
shortwave bands are anything
but exclusive. Non-ham
intruders are a constant
threat, creating QRM and
making DXing and especially
weak signal working a misery.
Here are just a few of the
ham band intruders spotted
and in some cases identified
recently by hams in the South
Pacific:
- Russian Morse characters sent with a poor quality TX on 14240kHz (for some reason Russia has a military allocation in the 20m amateur band)
- Encrypted speech in the 10m beacon sub-band with a RTTY-like synchronizing signal.
-
Hand-sent 24wpm CW on
14014 kHz from a non-ham
station signing
"SNZL".
He was initially sending
VVVs, then called
“DQ2L DE SNZL ZJT
ZQQ ZVU ... DQ2L DQ2L
DQ2L DE SNZL SNZL ZJT ZQQ
ZVU [during which
he made a mistake and
sent 8 dots] ... DQ2L
DQ2L DQ2L DE SNZL SNZL
ZJT ZQQ ZVU
QYT6K" I
presume this was a
military station misusing
the 20m ham band.
- A
sprog/mixing product on
1908kHz from two
commercial MW AM
broadcast stations in
Christchurch, ZL
- A pirate using the call ZL9BI on 30m CW and calling himself “Tom”,
believed to be in the
vicinity of ZL but not
due South of us where
Auckland and Campbell
Islands are ...
-
A dubious CW op called “Fred” variously using the calls FR6GTO, FR6GTO/P [10Mb MP3!]and FR/F6GTO but seemingly located in Europe, not Reunion
- Fishing buoys transmitting on 10m from somewhere on an Easterly bearing from ZL, plus many more around the globe on 160m
-
A VK/ZL propagation radar system accidentally QRMing 30 and 20m (more below)
- A
carrier with 60Hz hum
modulation sitting on
14000 kHz, transmitting
from the North East of ZL
-
Commercial broadcasters
from P5, BY, ET and
elsewhere, broadcasting
mostly on 80m and 40m
regardless of the ITU regs
-
Pirate fishermen from 4S7 and villagers in YB using ham equipment (presumably) to chat to each other using SSB on various ham segments on 5kHz channel spacings
-
Illegal CBers
transmitting nasty AM and FM signals on the high HF bands, at times wiping out the ham beacons and causing QRM to legitimate ham QSOs
- The
dreadful buzzsaw Over The Horizon Radars (OTHR) from BY (~43 pulses per second), 5B4 (~50 pps) and/or F and elsewhere (including the phantom pharter at ~80 pps and the chopper at 26pps) that wipe out great chunks of prime shortwave ham spectrum at peak DXing times, reminiscent of the bone-crunching dakka-dakka Woodpecker formerly broadcast from a massive antenna array near Chernobyl until finally their UPS burnt out ...
- The
swish-swish washing
machine noises made by wave radar (called CODAR),
often accompanying OTHR
- RTTY and other data-mode ham band intruders, including a curious 10 kHz-wide fog horn,
various encrypted/indecypherable data signals and, um, a Dalek
- Gurgling water 17m harmonic/spurious mixing product of a Cuban broadcast station on some lower band
-
Dotters, channel markers, fishing buoys, licensed ham beacons or unlicensed pirate beacons typically sending curious callsigns or strings of single letters such as N N N N,
T T T T or E E E E or V V
V V from various
locations ...
- All
manner of wideband HF
noise sources allegedly
doing double service as
WiFi routers, plasma TVs, PLT/mains networking and ten zillion cheap and nasty unsuppressed switchmode power supplies raising the noise floor for all of us in the same manner as light pollution threatens Earth-bound astronomy
A technical configuration issue with the TIGER experimental propagation monitoring radar system demonstrates the value of Intruder Watch. Hams noticed and started complaining about what sounded like data mode transmissions particularly in the 30m band and sometimes on 20m too. Through the Google group (more below), we started working as a team to investigate the source. The direction was hard to pin down but seemed to be roughly South or West of ZL, an unusual direction for any short path signals! Eventually, the intruder was traced through the TIGER website which conveniently reports the frequencies being scanned, and sure enough the radar was spending a fair bit of time in the 30m band. The 30m band is not an exclusive ham band so we have more limited options than with, say, 20m but investigating the TIGER system further led to the discovery that their license forbids interference to other services, in other words they are not a primary user of 30m either. Contact with the TIGER team led to the equipment being checked and the problem being traced to a configuration option that was supposed to prevent transmission in the 20 and 30m bands but had somehow been lost. The system was taken off-air for most of a day and reconfigured to skip the ham bands (plus guard bands on either side) and peaceful DXing resumed on 20 & 30m - a good result all round! Thanks to the Intruder Watchers and TIGER team for responding so positively.
Given the popularity of
soundcard digital modes among
amateurs, it’s often
hard to figure out whether a
given jangly noise on air is
a legitimate ham digital
transmission using an obscure
or new mode, or a commercial
intruder.
Unfortunately, although some
digital modes software
supports several modes,
decoding unknown signal types
is often impossible without
knowing the precise ode i.e. the bandwidth, number of signal frequencies, speed of transmission etc.
Sometimes the band frequency
used is characteristic, but
mostly we rely on the
characteristic sounds of the
different modes to identify
them by ear. Soundbytes of intruders and QRM sources on the IARU Region 1 website help identify commercial data modes etc. Another site has audio
samples of many ham and
commercial data transmissions, and here’s another good one, while the Fldigi website also has sample waterfalls to accompany the soundbytes.
For what it’s worth, the most common digital modes on the HF bands are probably
RTTY (45.5 baud, 170
Hz shift) and PSK31
, plus Olivia (either
16 tones within a 500 Hz
bandwidth or 32 tones within
a 1000 Hz bandwidth)
and JT65
(particularly on the WSPRnet frequencies). To hear what these signals sound like, tune through 14060 to 14110 kHz whenever 20m is open. RTTY signals will often be heard around 14080-90, PSK31 clustered around 14070, Olivia around 14076 or 14107, and JT65/WSPRnet around 14095. There are also
SSTV
signals on or near 14230. These are not the official ITU designations for types of emission, but if you’re interested, feel free to look them up.
Tip: check the Hamspots website to find who is currently active on what modes and frequencies.
I am the deputy Monitoring Service Coordinator for NZART’s Monitoring Service,
supporting the main man John
ZL1GWE.
I run a Google Group (email reflector) for Australasian and South Pacific hams to report and share information on ham band intruders affecting IARU Region 3.
All Australasian hams who
are concerned about non-ham
intruders on the amateur
bands are welcome to join the
group, earwig for a while
to find out how it works and
then hopefully contribute
details of intruders such as
the times (plus durations if
possible) and frequencies
heard, MP3 recordings (most
of us use Audacity with the
Lame plugin to make MP3s),
waterfall spectra, signal
strengths and ideally
directions, or perhaps just a
note about other identified
signals heard at the same
time. It all
helps. Information on
intruders is collated from
the reflector and other
sources to contribute to the
IARU Monitoring Service
reports, and to persuade the
authorities to act on clear
infringements.
Current and former IARU
Monitoring Service people
belong to the group and
frequently share their wisdom
and knowledge with us, for
example helping us identify
stations or give us tips on
how to DF (Direction
Find). As an example, I
wrongly assumed curious mis-timed CW signals in the SSB segment of 20m, and similar indecipherable code on 7015kHz one ZL evening, were intruders but most likely they were legitimate Wabun Morse sent by ancient JA hams using hand keys, evidently. Far from being intruders, these are historic ham masterpieces! Each Wabun character is a Japanese kana, with the Wabun transmissions starting with the DO prosign. Fascinating stuff.
Listings of shortwave
intruders (plus some
legitimate users such as the
NCDXC propagation beacons!)
that have been professionally
DF’d and identified are
published once a quarter by
the ITU: here are the lists
for Q1 2009, Q2 2009 and Q3 2009.
Read how modern
software-defined radios are
used to interpret complex
signals received by antenna
arrays for professional, if
not amateur HF direction finding purposes.
Use one of the web-enabled
SDR to cross-check any QRM
you find, for example this Dutch SDR.
Unfortunately, irresponsible, incompetent and intolerant hams create a lot of QRM too. The EU zoo sometimes reaches nightmare proportions. Just listen to this outrageous behaviour heard on a DXpedition station’s TX frequency when someone quite rightly complained about their pileup wiping out a maritime net monitoring for news of a South Pacific tsunami. It’s a sad sign when somone can set up a website to name-and-shame the ham QRMers, pirates and lids, including sometimes
placeholders ready and waiting for the next big DXpedition, or
a LidList ...
DXpeditioners often jostle for position at the bottom ends of
the bands on CW, or on the usual RTTY and SSB spots further up, causing chaos if their pileups
intermingle. Partly this is down to the DXpeditioners who choose the listening frequencies they
announce and where they actually listen (not necessarily the same places!) but mostly it is caused
by over-excited and inconsiderate DXers who don’t listen on their TX frequencies. Frequency cops
who take out their frustration by berating them on the same TX frequencies just make the problem
worse. For more advice on how to reduce this self-made ham problem, look here.
Lastly there are the rude, ignorant and selfish hams who just keep right on calling, regardless of any
instructions to the contrary. This is quite a different situation to those who make the occasional
mistake, call out of turn or on the wrong frequency. Good operators may still make mistakes but
not very often, and they immediately correct themselves as soon as they realise. The deliberate
QRMers don’t stop, even when everyone else understands and obeys the instructions, for example
when I sent “<AS> <AS> <AS> PLS QRX” at 12 wpm but EA7BW still carried on repeatedly calling
me (giving my call and his, several times of course just to make quite sure everyone knew he was
causing the QRM), wiping out my QSO with a patient and polite JA on 15m. If a lid like EA7BW
behaved like this in person, face-to-face, interrupting conversations by shouting his name over and
over, he’d get a b loody nose but, presumably feeling safe and secure behind his transceiver in some
far-off land, he evidently thinks it acceptable to stamp all over other operators
, doing his level best to spoil everyone’s fun. The thing is, every time he sends
his callsign, he identifies himself unambiguously as the obnoxious cretin to
everybody listening. “
LISTEN TO ME! I’M AN IDIOTIC LOUD-MOUTHED
THUG!
” he shouts to the whole world, while quietly we record the evidence
and inform the authorities <cue evil laugh> Even more galling is when a lid
then pesters me for a QSL card or LoTW confirmation - no chance mate!
Consider yourself blacklisted. Read the DX Code and grow up.
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