Code of Practice for RSGB VHF/UHF/SHF Contests

1. Obtain permission from the landowner or agent before using the site and check this permission includes right of access. Observe the Country Code.

2. Look at last year’s results to see if another group used the site and come to an amicable agreement before the event. Groups are advised to select a possible alternative site.

3. All transmitters generate unwanted signals; it is the level that matters. When operating from a good site, levels, which might be acceptable from home, can be a problem to stations within line of sight and beyond.

4. All receivers are prone to spurious responses, particularly in the presence of strong signals. Such responses can mislead an operator into believing that the incoming signal is at fault, when in fact the fault lies in the receiver.

5. Test the transmitter and receiver on air before the contest, looking for in-band spurious emissions and responses. This should be done with the power source that will be used in the contest. Appendix 1 shows the expected standards.

6. Contesters cannot claim exclusive use of any band and should obey the RSGB/IARU R1 band plan avoiding spot frequencies designated for other purposes e.g. the 50.100 to 50.130MHz DX window, 144.300MHz centre of activity and the 144.250MHz GB2RS news frequency at its scheduled broadcast time. If asked to QSY because of interference to any such user, please do so quickly and courteously.

7. Inform stations apparently radiating poor signals, but only after checking your own receiver. If the station is very strong then you should take steps to reduce the signal to a level, which is similar to that seen with clean signals. Turning the beam or adding an attenuator after switching off the masthead amplifier should achieve this goal. If asked to close down by a Government Official or the site owner, do so at once and without objectionable behaviour. Above all, always be friendly and polite.

Appendix 1

Expected standards for spurious emissions

To achieve the required levels radiated noise should be less than -95 dBc/Hz at 10 kHz offset reducing to  125dBc/Hz (100 watts or less, single antenna) or -135dBc/Hz (greater than 100 watts and/or multiple antenna) at 50kHz or greater offset.

These standards for composite noise may be relaxed by 6 dB per octave above 1GHz.

Care should be taken to ensure that ALC overshoot does not take place as this can lead to broadband transient emissions.

A greater than 100dB spurious free dynamic range measured in a 3kHz bandwidth is desirable for a contest receiver.

When choosing equipment for contest operation, read and take note of the RSGB and ARRL equipment reviews and read the article published in March 2016 RADCOM by G8DOH.