WA5TKU with the beacon ( the gold  box in the centre)                                     The 902/1296 Antennas

The 902/1296 beacon chassis contains 2 beacons. One runs up to 18Watts on 902.380MHz. The other beacon runs up to 3 Watts on 1296.380MHz. Both are keyed by the same intelligent keyer which as well as keying the callsigns also provides cw indications of the 902MHz power output, 1296MHz output, Chassis temperature and supply volts. To ensure thermal stability the oscillator modules of both beacons are powered up continuously. However the Power amplifiers can be turned on and off remotely using the dtmf control board which receives audio from a beacon control receiver. This access is controlled with a security code.

The 902 Beacon starts with a G4DDK designed DDK000 oscillator strip that was originally designed as part of a UK TACS transmitter local oscillator at 850MHz. It starts with a 112.7975MHz crystal and has a total multiplication factor of 8.  The semiconductor lineup is BFY90, BFY90, BFR91, BFR91 and produces around 5mW. FSK is provided by a varactor diode "loosely" connected across the oscillator coil.

The amplifier is a STM15 linear module designed for European GSM service donated by WA1ZMS. It is capable of producing up to 18W, a potentiometer mounted on the Modules bias PCB adjusts the power up to this value. A coupling line is printed on the PCB, which with the addition of a diode feeds a dc power level voltage to the intelligent keyer.

The 1296MHz beacon starts with the G4DDK designed DDK001b oscillator circuit. The semiconductor lineup is BFS17a, BFS17a, BFR93A, BFR93A and produces around 5mW. The total multiplication is times 12. It employs a 108.006MHz crystal cut for 50 Degrees Centigrade which is fitted with a Murata BG330N 50 degrees C heating element. FSK is provided by a varactor diode "loosely" connected across the oscillator coil. The oscillator is contained in a tinplate box with lid.

The amplifier is a Mitsubishi M67715 linear hybrid module mounted on a DEMI 2303PAPCB. The main supply voltage is 13.8V but the bias pins are supplied from a 7808 regulator attached to the chassis. The output power is a maximum of 3W, no power adjustment is provided. A coupling line is mounted above the output track, which with the addition of a diode feeds a dc power level voltage to the intelligent keyer.