LF: Multipurpose beacon

[Andy Talbot <andy.g4jnt@googlemail.com>]

Thanks to John G3WKL and to Rod Wilkinson of OFCOM, I now have  Official Sanction to run the 'Multi Function' beacon  (Well, can you think of a better name for it !) beacon on 503.7kHz  in continuous unattended operation.   So now I don't have to switch off on going to work etc - something that was too easy to forget to do!

 

To reiterate :  

 

Same signalling protocol as the 5MHz beacons GB3RAL / WES and ORK, but with the sounder sequence replaced by PSK31.   The transmissions are every 15 minutes offset by four minutes, so starting at 04, 19, 34 and 49 minutes past the hour.   Format consists of CW ident for the  00 to 07 seconds interval, then two sets of power steps with the power reduced by 6dB each second for the 7 to 25 seconds period,  A 100ms break before each power step makes aural listening to determine the change point and count the audible ones a little easier.  Then full carrier for 25 - 30 seconds for the automatic logging software.   PSK31 takes the 30 to (48)s interval  then plain carrier to complete the minute timeslot.

 

Automatic logging software can be obtained from  http://www.rsgb-spectrumforum.org.uk/5mhz%20beacon%20monitoring.htm

Set the timing interval by -240 seconds and this beacon will be logged with the red trace, as if it were GB3RAL.  the 5 and 6 minute slots, green and blue traces respectively, are occasionally used by other stations. 

 

G4WGT has a grabber monitoring this transmission at  http://myweb.tiscali.co.uk/wgtaylor/grabber3.html

 

Andy  G4JNT

www.g4jnt.com