FREQUENCY SURVEY

Aim

The aim of this survey is to identify the frequencies of licensed users within the UK that might cause interference to those competitors wishing to use RC equipment that is designed to transmit on a legal frequency in their own country, when competing in the F5B & D World Championships, to be held at York in August 2004.

Legal frequencies in the UK for Airborne use only

The frequency band approved for exclusive use in the UK is 34.945 MHz to 35.305 MHz. There are 36 discreet channels each spaced 10 KHz apart and numbered 55 (34.950 MHz) to 90 (35.300 MHz). Other bands permitted for airborne use are in the 27 MHz band, which is shared with citizen band radio, and in the 459 MHz band. Telemetry is permitted in the band 433.05 to 434.79 MHz.

The 35 MHz band, as defined above, is also the approved band in most European countries except France. It is strongly recommended that use of this band is the first choice of those entering these championships. It will also be possible for the organisers to monitor use of these frequencies on the site. Note that the additional frequencies 35.820 MHz to 35.910 MHz, permitted in some European countries including Germany, should not be used. Short range emergency alarm systems for the aged and infirm operate on three spot frequencies in this band, 34.925, 34.950 and 34.975 MHz, they are exempt from licensing.

Frequencies used in other countries

Use of the following frequency bands has been considered in this survey :

36 MHz band(36.010 - 36.590) used in Australia
40 MHz band(40.665 - 40.695) used in Germany
(40.665 - 40.985) used in Switzerland;
(40.710 - 40.850) used in Japan;
41 MHz band(41.000 - 41.200) used in France;
60 MHz band(60.025 - 60.375) used in South Africa;
72 MHz band(72.010 - 72.990) used in Canada and USA;
(72.130 - 72.210; 72.790,72.830,72.870) used in Japan.

A discussion of their use in the UK follows.

36 MHz band (36.010 - 36.590)

36.200, 36.350, 36.450 (AM and narrow band FM) are used nationwide for tactical Defence purposes. The power of the mobiles is likely to be in excess of those used by RC transmitters and use of this band is not recommended. Note that cordless audio devices for use with domestic audio equipment operate in the band 36.61 MHz - 36.79 MHz.

40 MHz band (40.665 - 40.985)

The sub-band 40.660-41.00 MHz is exclusively for surface model control use (cars and boats) which are exempt from licensing. Airborne use of this band is not permitted in the UK and therefore entries will not be accepted proposing use of frequencies in this band.

41 MHz band (41.000 - 41.200)

Defence tactical communications use 41.100, 41.125, 41.175 MHz. The radiated power of the mobiles is likely to be significantly in excess of those used by RC transmitters and use of this band is not advisable on grounds of safety.

60 MHz band (60.025 - 60.375)

Low powered radio microphones use a total of 4.0 MHz within the band 52 MHz to 68 MHz. BBC 5W cordless and outside broadcast microphones use 60.295 MHz. There is possible allocation of 46-68 MHz to wind profiler radars on a case-by-case basis, details of which are not known. Since possible use in this band for RC purposes is limited to South Africa, who also have 35.00 MHz to 35.240 MHz available to them, it is not intended to ask for a temporary use permit in this band.

72 MHz band (72.010 - 72.990)

A large number (in excess of 400) of nationwide commercial mobile users are licensed in this band and there are major public roads and factories in close proximity to the flying site. The power of these mobiles is likely to be considerably in excess of those used by RC transmitters and therefore use of this band is not recommended.
A major user is the Automobile Association who have mobile patrols using narrow band FM on 72.000, 72.0125, 72.025, 72.0375, 72.050, 72.0625, 72.075, 72.0875, 72.6875 and 72.700. The Royal Automobile Club uses 72.1875, 72.200, 72.2625, 72.275, The British Broadcasting Corporation use 72.225. Parceline Ltd and Express Security use 72.300. The Department of Trade and Industry use 72.3125, 72.3750. Phillips and British Telecomm use 72.3500. Tarmac Roadstone use 72.4750. Community repeaters use 72.500. Hotpoint use 72.5125 (specifically in York) and 72.7625 elsewhere. Ambulance services use 72.5375. Radiophone use 72.6625. Cryston Communications use 72.7750. NT Ltd and Vibroplant plc use 72.8000. Secure government mobiles use 72.800 and MOD tactical mobiles use 73.000. Many other users exist on other frequencies in this band but are not listed as nationwide users or as being located in the York area, nevertheless they represent a risk.

Conclusion

It is repeated that, of the legal frequencies available in the UK, use of the 35 MHz band, as defined above, is strongly recommended and that this should be the first choice of all those entering these championships. Competitors considering entering on other legal UK frequencies outside the 35MHz band (27 and 459 MHz) will be exposing themselves to some risk of interference as these bands are used by others, and thus the safety of people on the flying field and in the neighborhood could be compromised. The case for applying for a “Temporary Use Licence” for any alternative frequencies in legal use in other countries has been ruled out on the grounds of safety by the BMFA.