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One-tube crystal-v.f.o. input circuit

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There are several types of oscillator circuits I wlach make good crystal oscillators, but when these circuits are used following a v.f.o. they become temperamental and sometimes unstable. The circuit shown in Fig. 1 is a crystal-oscillator, grounded-grid amplifier which, with the flick of a switch, becomes a cathode-follower, grounded-grid amplifier for v.f.o. operation.

Fig 1
Fig. 1. Diagram of the crystal-v.f.o. circuit. Switch Si uld be a low-loss type. Leads to the switch and crystal should be kept as short as possible.

Patrick E. Hansel, K8DJK.