TEEANT1.PCX     Picture of the 'JNT Tee antenna

73NOISE.BMP     Seven days of noise measurement results in a 3 Hz bandwidth
                by G3PLX, made in July 1997

73NOISEA.PCX    Two days of noise measurement made by G4JNT in the same
                period

73RX2.PCX       Circuit diagram of portable 73kHz receiver.  Very non optimum
                gain distribution so don't copy too closely !

73DRIVER.PCX    Synthesised source for 73kHz in 10 Hz steps, with modulator
                for On/Off keying, BPSK and (slow) FSK

73RXLOOP.PCX    Diagram of typical receiving loop for 73kHz

32BPF.PCX       Circuit of approx 1 Hz bandwidth crystal filter using watch
                crystals at 32765.5Hz