As a result of feedback from last week's GB2RS
news item regarding the use of 145.200MHz and 145.800MHz by the International
Space Station, the RSGB Spectrum Forum feels some clarification is needed and
the following joint statement has been agreed with the IARU Region 1 Satellite
Co-coordinator, the RSGB's Radio Communications Voluntary Services and The
Radio Amateurs' Emergency Network Spectrum Forum members.
Although both the frequencies 145.200MHz and
145.800MHz have historically been used for domestic UK emergency
communications, it was agreed at the IARU Region 1 Conference in 1996 to
allocate 145.200MHz as an FM uplink channel with 145.800MHz serving as the
downlink side of the pair. This particular frequency pair, which applies only
for Region 1, had earlier been agreed by IARU internationally after
discussions with NASA and AMSAT.
The likelihood of an active ISS pass taking
place at the same time as bona fide UK emergency communications operations
using 145.200MHz and / or 145.800MHz is considered low and due to the nature
of circumstances would only be for a brief period in any case. In addition,
the UK amateur radio emergency communications community has for many years
discouraged the use of 145.800MHz as far as possible, and even then only using
low power and vertical polarisation, due in any case to its proximity to the
satellite sector.
UK terrestrial stations are therefore again
requested to check for activity from ISS before transmitting. Details of the
ISS orbits can be found on the
Internet.