The K.W. "One-Sixty" Transmitter is a CW/phone transmitter for the 1.8 me to 2 me amateur band, with a DC input of 10 watts. It incorporates full CW "break-in" working facilities, also provision for muting a receiver with normal simplex working. The variable frequency oscillator uses a EF80 valve in a "Clapp" oscillator on 900-1000 Kc/s. This is followed by a second EF80 as a frequency doubler, this being transformer coupled to a PL81 valve as a power amplifier. The i>F output of the transmitter is a pi-network filter suitable for direct feed to an end fed aerial or into a low Z co-axial line.