• Not All “Intruders” on Ham Bands are Illegal — But a Lot of Them Are

    From ARRL de WD1CKS@VERT/WLARB to QST on Thu Sep 14 20:38:06 2017
    09/14/2017

    The monthly newsletter[1] of the International Amateur Radio Union Region 1 Monitoring Service (IARUMS) typically makes for some interesting reading. While the reports that come from more than two dozen contributors in Europe and Africa can be a bit visually dense, the content conveys the impression that that there are myriad intruders on the Amateur Radio bands. However, not all of them are illegal, as IARUMS points out, but a lot of the signals heard are not supposed to be where they were monitored. The individual reports can be a bit humorous too.

    "Get the grub, and I'll talk to you later this evening," was a snippet of a conversation between two fishermen - identified as Mick and Jack - that an Irish Radio Transmitters Society (IRTS) monitor overheard on 3.570 MHz and reported to the IARUMS. The IRTS said the chatter was accompanied on both sides by "loud motor noise," and, if that were not sufficient detail, it pointed out that both men had Galway accents. Intruding signals from fishing crews throughout IARU Region 1 are commonplace.

    More blatant are the repeat offenders, such as the "Chinese foghorn" heard by over-the-horizon (OTH) radars on several frequencies in the exclusive Amateur Radio 20-meter allocation, as well as on 15 and 40 meters. IARUMS Region 1 Coordinator Wolf Hadel, DK2OM, said the signals, 10 kHz wide and with 50 and 66.66 sweeps per second, transmit in burst mode and often jump frequencies.

    Some signals from military stations on non-exclusive Amateur Radio allocations are legal. For example, the latest IARUMS newsletter cites the Stanag-4285 military signal that showed up for a few days in August on 5,361.8 kHz. The Stanag-4285 transmissions, coming from a Navy facility in Aarhus, quit on August 28. "Many thanks to the Danish Navy for leaving this frequency!" Hadel added, noting that the Danish Navy is a primary user. "We have to respect primary users!" he said.

    An Australian OTH radar "Jorn" showed up on 5,357 kHz. IARUMS noted that this is a primary user of that band.

    Adding a little mystery and intrigue to the compilation was a report from a radio amateur in the UK citing a "female voice with encrypted messages" on 14.212 MHz, believed to originate with the Foreign Intelligence Service of Ukraine in Rivne.

    In the "miscellaneous or bad news" category were some repeat offenders, such as Radio Hargaysa in Somalia on 7,120.0 kHz; Radio Eritrea and white noise interference from Radio Ethiopia persisting on 7,140.0 kHz and 7,180 kHz; a third harmonic of Radio Tajik on 4,765 kHz, showing up on 14,295.0 kHz; the Sound of Hope from Taiwan, transmitting on 18,080 kHz; the Russian Navy sending CW on 21,438.0 kHz, and Radio Iran "in burst mode" on 28,960.0 kHz, daily.

    True intruders are those appearing on exclusive Amateur Radio frequency allocations. Some domestic Amateur Radio HF allocations outside Region 2 (the Americas), such as 7.200 to 7.300 MHz, are either shared with other services or not available to radio amateurs. Only the 7.000 to 7.200 MHz segment of 40 meters is currently allocated exclusively to the Amateur Radio Service worldwide. On other ham radio HF allocations, such as the 30-meter band, Amateur Radio is secondary to other users. However, the 20, 17, 15, 12, and 10-meter bands are exclusively available to the Amateur Radio Service worldwide.


    [1] http://www.iarums-r1.org/iarums/news2017/news1708.pdf

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