• The first prototype IEEE competition transmitter (sans modulator) (lower right) and its schematic to the left.
    A 2 stage HF transmitter (above the schematic). Its signals have been heard in over 40 countries on 6 continents including Australia almost 20,000 km away. A 3 stage crystal receiver was constructed and features good sensitivity and selectivity.
    The receiver, left, is registering a signal on the meter from the 1 MHz transmitter, right. A 'scope shows the output of the transmitter.
    Schematics of the transmitter and receiver. The receiver covers 500-2000 kHz.
  • MF transmitter with VFO. Listen to its signal as recorded 1200 km away in the Labrador Sea, north of Nain by clicking here. The power output was about 0.5 watt. The clump of components in the centre is a 10 dB RF amp. A diode matr ix (left) is programmed to identify the transmissions.
    National Engineering week, 9 March 2002.