G0AFH Home

Welcome to the GB3VHF.CO.UK The WWW Home page of the Wrotham Beacon.

Updated February 2007. The GB3VHF beacon web pages have a new home. www.gb3vhf.co.uk

The new GB3VHF has now been in service for one year. During that time we have received a good number of reception reports but we would like to receive more. The beacon has been heard in 65 locator squares across Europe. The best DX currently stands at over 1100Km (SP6), and is regularly heard by stations over 500Km away.

Have you heard GB3VHF? If so then please submit a reception report.

On Sunday February 26, 2006 the old GB3VHF beacon was taken off air and replaced by a new state of the art beacon. Full details about the construction and development of the new beacon can be found in the press release.

Photographs thaken during the construction and testing of the new beacon may be found here, and here are a few taken during the installation.

GB3VHF is located on the BBC transmitter mast above Wrotham village on the edge of the North downs, 268M ASL.

Modes.

The following text is taken from the press release.

The most important feature of the new beacon is that by using the DDS, the beacon is able to be programmed to transmit new modes. As before, the beacon sends its callsign and locator in Morse, but using A1A (on /off) keying rather than FSK.

To enable the beacon to be monitored at extreme ranges, the beacon additionally transmits it's callsign and locator using WSJT JT65B mode.

The GPS also provides for the precise timing of the keying sequence, such that the JT65B sequence will start at every even minute past the hour for 48 seconds duration.

The Morse sequence will commence at the start of each odd minute past the hour and last for 13 seconds.

At the start of each odd minute 30 seconds past the hour, at a precisely timed point, 140 microseconds after the UTC one-second reference as signalled by the GPS receiver, the phase of the carrier is reversed, 28 times in total to fill up the 30 second time slot. The result is a 1 bit/second pattern of 10101010…..

Reception reports are most welcome. Please follow this link and use the feedback form to send your report. Include details of your call sign, locator or location, and any comments.

Data from the reception reports has been read intoVQLog and used to produce a map of squares where the beacon has been heard.

Mail from DF2ZC describing how to configure WSJT to receive GB3VHF using deep search mode.

New beacon weaker than the old one ??

We wish to thank the following Sponsors and Donors