load the tuned circuit

[Pat Pending]

Practical experience with this circuit is that the BC559c gives higher gain with less regeneration than the old OC170 was my point Jeffrey, the beta was just an easy method of illustration, not really claiming how applicable it is to anything in the real world (as we know!), it was just easy to stick them into the socket of my cheapest multimeter. I think the basic gain of the circuit in my post is very dependant on the transistor specs as it has the emitter grounded, (the gain control/reflex bias scheme wouldn't work otherwise, in fact to change to a silicon transistor you also need to change the diodes to silicon types too). The basic circuit was much beloved by Sir Clive Sinclair, in his miniature earphone sets from the sixties, micromatic et al.

Andy