![]()
|
GB3FM - GB3FN - GB3FX - GB3SN The GB3FNM Beacons The group also hosts microwave beacons on behalf of the UK
Microwave Group. The beacons operate on the following frequencies:
There is a plan to re-establish the non-functional 24 GHz beacon and a 47GHz beacon which was operational for a time has been taken off the air. The beacons on 5.7 GHz and above were developed, built and maintained by G8ACE and G4NNS and project managed by G8KQW. The 2.3 GHz beacon was developed, built and maintained by G4SJH, G1EHF and G8GTZ. The antenna systems are located at approximately 15 to 20m above ground level. Beacon descriptionsAll the active beacons nominally provide omni-directional coverage subject to variations in the antenna pattern. Where possible the antennas are oriented to favour directions up-country and towards the continent.The beacons provide a useful resource for propagation monitoring and enable microwave operators to check their receiving equipment. The complex consists of indoor units (IDU) which include the power supplies, keyers, stable frequency references and intermediate or final frequency generation. The intermediate frequency for the 5.7 GHz beacon and power are supplied to the corresponding mast mounted Outdoor Unit (ODU) via coaxial cables. Since early 2010, the OCXOs have been locked to the 5MHz reference used for the GB3FN and GB3FX repeaters, to give improved frequency stability. For the 2.3 GHz beacon the final frequency and power are supplied to the ODU (pictured below) for final amplification at the mast head. The 2.3 GHz beacon uses GPS frequency stabilisation. |