19-01-2018, 02:51 PM
(19-01-2018, 11:55 AM)Diabolical Artificer Wrote: Unusually chassis/ground is positive ...
... both use germanium Q's and diodes.
Not unusual at all! The germanium transistors will be PNP devices. If built in conventional manner with emitter connected to ground and collector to HT (via other components, of course!) then the HT will be negative and ground positive. Look at just about any early transistor radio circuit and you will find exactly the same arrangement.
NPN transistors, of course, work the other way up so the introduction of silicon transistors saw the return to a 'conventional' valve type arrangement with a positive HT rail.
