An all bands VXO Transmitter

Originally published in SPRAT Autumn 1981 Issue 28

Designed by GM3OXX George Burt

PARTS: The oscillator BC107; the PA any suitable RF Output transistor, e.g . 2N3866, 2N4427; Keying switch is a BCY39 but this can be omitted and hand keying used.

The circuit is quite simple, but the oscillator and the PA are RF and DC coupled; the oscillator will not go without the PA,the 39 ohm and the 0.1uF in the PA emitter to ground. Do not make the 39 ohm resistor too small, as the PA is biased by the osc transistor and the PA will draw excessive current. The resistor should be adjusted for Power in..

The circuit will oscillate with any fundamental crystal. The output should be connected through a Low Pass Filter. Suitable design can be found in the NEW RADIO CONSTRUCTOR RECIPE CARDS by George Dobbs G3RJV which can be obtained from the G QRP CLUB

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