Hi All.

John, I can remember building a Rx using three 807's in which one was strapped as a triode as RF amp. In the mid 1950's they were often for sale at less than one shilling each (I shilling = 12 pence, £1 = 240 pence brfore the UK went decimal coinage). They would run with 45VDC on anode (plate) as HT (B+). For an impoverished schoolboy they were magic! When "three-legged fuses" arrived many of us were shocked that someone had invented a destructable active device which didn't have a filament (heater), couldn't be made to glow purple and would "destruct" without a visible sign to suggest that it had ever been connected to an electrical supply !

 

However, my ability to construct a Rx in a Woolworth plastic lunch box which would provide test match commentary in a corner of the school yard at lunchtimes with three-legged devices identified only by the colour of a paint spot, gained me so much popularity from my fellows (I cannot now remember what the equivalent epithet to "nerd" was) that I soon stopped believing that RCA 807 = "The Holy Grail" !

 

73 de Pat g4gvw