GB3NGI Radio Beacons


432 MHz Beacon


Frequency: 432.482 MHz
ERP: 24dBW
Heading: 45° and 135°
Locator: IO65VB27
Location: Slieve Annora
Keeper: Gordon Curry GI6ATZ



The 432 MHZ Beacon uses the Next Generation Beacon hardware: -
http://www.rudius.net/oz2m/




The reference 10 MHz Oscillator for the beacon source is derived from a GPS Disciplined Oscillator designed and built by James Miller G3RUH. More information on the GPSDO can be found here: -

http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm

The beacon generates both CW and JT65b coding allowing the transmitted signals to be decoded either by ear or by the WSJT software written by Joe Taylor K1JT: -

http://www.physics.princeton.edu/pulsar/K1JT/wsjt.html

The Beacon has an RF output power of 20 watts.
The beacon transmits JT65b on the even minutes and CW on the odd minutes in the following sequence: -

00:01 – 00:51 GB3NGI IO65VB in JT65b mode
00:52 – 01:00 GB3NGI IO65VB in CW
01:01 – 01:29 Plain Carrier
01:30 – 01:40 GB3NGI IO65VB in CW
01:41 – 02:00 Plain Carrier

The sequence then repeats

To decode the JT65b, tune the carrier to obtain a tone of 1500Hz with the receiver set to USB, and the dial frequency reading 432.4805. The JT65b will then be tuned in correctly.

The antennas used for the 432 MHz beacon are a pair of 9-element Antennas-Amplifiers yagis designed and built by Goran YU1CF :-

https://antennas-amplifiers.com/product/70cm-antenna/70cm-rear-mount-wideband-strong-yagi/

The antennas are connected to the transmitter using Andrews LDF 450 cable via a 2-way power divided supplied by Matt M0MAT :-

https://m0mat.co.uk/

The yagis are on a heading of 45° & 135° and are 10 metres above ground level.



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