The GB3BUX VHF beacons are located just to the south of Buxton in Derbyshire, England, locator: IO93BF
GB3BUX operates on exactly 50.000.0 MHz and 70.000.0 MHz.
The antenna system is omnidirectional with horizontal polarization. The twin stacked turnstiles are coupled via mast-mounted ATU's at about 15 feet above ground level. Each beacon operates at 25 watts ERP.
Both beacons transmit the same sequence, which is locked to the 60kHz MSF Anthorn (was Rugby) time and frequency standard. The keying sequence allows users to examine the signal at 10 sweeps a second on an oscilloscope for propagation studies. During each second, there is now a 10 millisecond carrier break every 100 milliseconds, with a 40 millisecond break on the second. The callsign identifications are - "GB3BUX" on the minute and "GB3BUX IO93BF" on the five-minute mark.
The beacons are excited from the same RF source, which is a precision 5MHz frequency standard divided down to 10kHz for comparison and locked to the off-air 60kHz carrier from the MSF station. The 5MHz is doubled to 10MHz and distributed to each beacon. The 50MHz beacon uses a x5 multiplier and the 70MHz beacon a x7 multiplier. This affords RF driver accuracy locked to the 60kHz MSF standard. In the event of a mains power failure, the system will switch over to standby batteries.
The beacon keeper is Nick, G7EKY, on behalf of the Buxton Radio Amateurs.
Last modified: 2011-01-22 00:03:35, 1828 bytes cached
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