plot
Predicted coverage area

spare
        Main and standby 3cm beacon units

pa
              1W PA and driver module

ant
 3cm Waveguide slot antenna and location
antennas


south


west

Select 'view image' on your browser for larger pictures


GB3CAM    Cambridge microwave beacons
IO92WI          Wyton           Cambridgeshire                                                                                                         
 

3cm:  10368.755 MHz                                1.2cm:   24048.870 MHz

reports always welcome, either direct ( gb3cam[at]earf.co.uk ) or via www.beaconspot.eu                       
                                                                                                                                                                                      

The first of the two Cambridge microwave beacons came on-air on 10th July 2008. This was the 10 GHz
beacon.  Although Wyton is only some 35m asl, the beacon antennas are 30m above ground level - well
above the local tree cover. There is some obstruction due to other antennas on the same site however.
.
beacon-details


It is hoped that the 24 GHz beacon will go live some time in August 2008.




'Spots' added to www.beaconspot.eu within first week of operation (3cm)
beaconspot


 
3cm beacon frequency error history:

Measurent date
10.06.08
16.07.08
23.07.08
30.07.08
06.08.08
13.08.08
20.08.08
27.08.08
Error
-130Hz
-140 Hz
-180Hz
-240Hz
-260Hz
-330Hz
-250Hz
-360Hz

[This is quite an error, and does not relate well to what was found during initial soak testing (less than 100 Hz error). The
5 MHz reference is quite elderly (at least 25 year old), and the coarse tune trimmer is a little intermittant, so I believe all the
mechanical bumps of moving the beacon onto site has upset the trimmer - certainly the temperature excursions on the new
site are noticeably less than during soak testing]




For more 3cm details see: http://www.earf.co.uk/3cm_proposal1.htm