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The following information was kindly provided by RAC's Monitoring Coordinator,

The International Amateur Radio Union (I.A.R.U.) Monitoring Service is world wide in scope.  It was started in England shortly after World War II when it became apparent that many countries were not observing the peace time provisions of International Agreements signed after wartime.

Today the problem is just as bad or worse.  Some countries do not even observe the treaties and agreements signed by their own administrations.  Of particular concern to us are the violations of "exclusive" world wide HF amateur frequencies.


10 metres...

28.000 to 29.700 is EXCLUSIVE WORLD WIDE AMATEUR - any non-amateur signal is an intruder.

15 metres...

21.000 to 21.450 is EXCLUSIVE WORLD WIDE AMATEUR - any non-amateur signal is an intruder.

20 metres...

14.000 to 14.250 is EXCLUSIVE WORLD WIDE AMATEUR - any non-amateur signal is an intruder.

14.250 to 14.350 is shared with many fixed services (including China and USSR), however "broadcasting" is not a permitted use.

40 metres...

7.000 to 7.050 is shared equally with the fixed services of many countries, mostly African nations.

7.050 to 7.100 is EXCLUSIVE WORLD WIDE AMATEUR - any non-amateur signal is an intruder.

All other portions of the HF amateur bands are shared with other services and much care is required to avoid wasting a lot of time and effort reporting stations who are legitimately sharing the bands with us.

Obviously, the more "ears" we have across the country, the better our reporting system will be.


The following is a short list of some of the intruders which have been heard in North America:

RAC Logo 7002.0 kHz Morse beacon "V", probably Russian
RAC Logo 7039 +/- cluster of Morse beacons, "C", "F" ,"P" and "S", probably Russian
RAC Logo 7070.0 - 7100 various shortwave broadcast stations
RAC Logo 14001 persistent carrier, on continuously for 23 days in March/April 99

Intruders can appear anywhere and at any time, depending on propagation and their own operational requirement to communicate.  During periods of reliable propagation, no amateur band is immune to intruders.


Some of the more persistent and widely noted intruders that have been removed from our bands in the last few years:

RAC Logo SWBC station Adventist World Radio on 7100 khz - their lower sideband of the AM signal is in exclusive amateur radio territory
RAC Logo A Peruvian SWBC station near 7040.6 khz
RAC Logo Radio Ankara, Turkey on 7100 khz.
RAC Logo VRQ, 14090 khz, a fixed service station in Vietnam.
RAC Logo 14126.6 - a Russian 3 printer data system


In order for national and international telecommunications authorities to properly identify an intruding signal, it is important that the frequency of the signal be measured as accurately as possible.  Radio amateurs with modern digital receivers can usually "measure" frequencies to the nearest 100 or even 10 hertz, provided that the receiver's calibration has been verified recently.  By carefully using some special techniques, even owners of analogue receiving equipment can measure frequencies to these same accuracies.

Besides accurately measuring the frequency, it is necessary to follow a standard convention about which "frequency" to measure:

a) For all amplitude modulated signals, such as:

RAC Logo A1A on-off-keyed carrier (as in "CW" Morse),
RAC Logo A3E double-sideband with full carrier ("AM", "broadcast", etc.),
RAC Logo J3E single-sideband ("SSB") suppressed carrier,
RAC Logo J8E independent sideband ("ISB"), and
RAC Logo N0N unmodulated carrier

measure the frequency of the carrier, even though the carrier might be suppressed.

b) For all frequency modulated signals, such as :
RAC Logo F1A or F1B frequency-shift-keyed (FSK Morse, RTTY, FSK packet, etc.),
RAC Logo F3C FM facsimile, F3E FM telephony ("FM broadcast"), and
RAC Logo F7B 4-frequency diplex radioprinter

measure the centre frequency of the emission, that is, half-way between the upper and lower edges of the signal.

c) For complex emissions not covered by the above examples, such as multi-channel and multi-tone radioprinter, and pulsed carrier or swept frequency emissions, such as ionospheric sounders and over-the-horizon HF radars, measure the centre frequency of the emission.  (If the centre frequency is actually outside of the hamband, it might be appropriate to add a note about the bandwidth of the signal or that the signal covers from frequency "x" to frequency "y".)

In all cases, if you cannot accurately determine the frequency of the emission, note it down as accurately as you can and add "EST" for estimated.  And remember that even though your receiver dial may indicate frequencies to a precision of, say, hundredths of a kilohertz, it may still be in error by several hundred hertz, depending on the calibration of the circuits and the band on which you are operating. It is important to verify the calibration of your dial!


Radio monitors, amateurs and SWL's alike, can assist by reporting intruders. Your report, along with others, will be forwarded to our IARU Region II Coordinator and from there steps will be taken to deal with the intruder.  In many cases, the methods are long, tedious and time consuming but they do often have the desired result.  If no one protests the intruders certainly will not leave, so it is up to us to bring attention to those who are operating outside their proper frequency allocations.

Reports should contain the following, as a minimum.

1. Frequency measured as accurately as you can, in accordance with the outline given above.

2. Time, date, duration. Always use UTC.

3. Type of Emission, as detailed above.

4: Identification, details of call signs or programming, things that can help us identify the source of the broadcast.

Signal strength and beam headings are also useful.

If you are uncertain of what you are hearing is really an intruder, report it to me anyway.  If it is a legitimate user, no harm has been done.

Reports should be sent to: