GB3CMS 10GHz Microwave Beacon

As a service to amateurs far and wide ERG maintains and operates GB3CMS, a beacon on the 10GHz microwave band. Originally based in Danbury, an application is in progress to move it to the Chelmsford area. Please make beacon keeping a more rewarding activity than normal by giving us feedback such as signal reports from afar.

Status: Off Air - pending site move approval/upgrades

Frequency 10.368960 GHz
Keyer Mode F1A CW
Equipment G4DDK004/G3WDG001 Masthead Tx, G4FUF Keyer/PSU
Power Tx -13dBW, PEP-3dBW (prior to upgrade)
Antenna Horizontally Polarised Omnidirectional Slotted Waveguide
(10-slot winged K5SXK/WA5VJB based design)
Location JO01GQ09 - Chelmsford, Essex - NGR TL 730 039

Gallery Pictures:-
Pictures of the GB3CMS Keyer Unit and Masthead RF Unit/Antenna can be found in the ERG Gallery

Slotted Waveguide Antenna:-

  • Files:   Antenna Design Paper, Outline Drawing, GB3CMS Antenna Patterns, Water Drain
  • Pictures: Slotted Antenna, Construction, Radome

    More About Microwaves...
    If you are interested in microwave operation and want to know more, visit the UK Microwave Group.


    Some earlier history...
    GB3CMS was the third system ERG put on air in Feb 1990 after DA/ER following an application made in Oct-1988. Original construction was largely by Keith G4FUF.

    • An application to raise its output power by 10dB was made in RMC Submission Batch 117 in July 1999.
    • A replacement application was submitted in Sept-2006 to Ofcom and approved on 30-May-2007
    • A new G8ACE Source/Multiplier has replaced the former DDK/WDG001 stages
    • Now reconfigured for the 108.04MHz source to be in the indoor drive/PSU unit

    26-May-2016