IARU Region 2 Monitoring System

Home Report Documents Tech Stuff Newsletters Contact the MS IARU Region 2


VHF/UHF  INTRUDERS


A growing problem is the number of intruders in our VHF and UHF Amateur bands. One supposes that intruders buy Amateur Radio equipment without having the required Amateur licences and then use the equipment for their own purposes, private or commercial. Due to the nature of radio wave propagation at these frequencies, most of the problems remain local in nature, affecting only Amateurs within line-of-sight of the intruder's antenna or slightly beyond.  

We encourage national Amateur Radio societies in Region 2 to bring these interference problems promptly to the attention of their national administrations, and we ask national monitoring system coordinators to include information about these intrusions in their monthly reports to the IARU Region 2 MS Coordinator.

In Region 2 (except in Cuba and Guyana), all VHF/UHF Amateur bands except the 2 and 6 meters bands are shared with other services, so it is necessary to be certain that the "intruder" does not belong to one of the other permitted services before making a complaint to the administration.

A more serious problem arises when the radio frequency used by an intruder falls within one of the uplink sub-bands used by an Amateur Satellite. The interference is the relayed by the satellite and it will affect Amateurs hundreds and even thousands of kilometres away.  In this case, affected Amateurs must complain through their national societies and national administrations to authorities in neighbouring or more distant countries.

Satellite uplink sub-bands are as follows :
    21.250 -   21.300 MHz
    29.300 -   29.510 MHz
  145.800 - 146.000 MHz
  435 -   438 MHz
1260 - 1270 MHz		 Uplinks only; not used at present.
Up and downlinks; not used at present.
Up and downlinks.
Up and downlinks.
Uplinks only.
Occasionally, a frequency outside of these sub-bands might be used by certain satellites. One such is 144.49 MHz, used by the International Space Station (ARISS) to receive FM Voice uplinks while over Regions 2 and 3.

Satellite users who experience non-Amateur interference in a satellite downlink should report this interference to the Monitoring System Coordinator of their national Amateur Radio society, and also to the IARU Amateur Satellite Coordinator, Hans Blondeel Timermann PB2T, at pb2t@me.com. See the page about Reporting an Intruder for some additional technical information on reporting interference to Amateur Satellite communications.

Home