18-05-2020, 11:43 AM
The old valve books properly explain oscillators far better than any transistor book. The three LC topologies usually for RF, relaxation osc (try a neon rather than Unijunction transistor) and RC oscillators such as phase shift.
Op-amps and double balanced multipliers (Gilbert cell like) also developed and explained in the valve era.
Almost all the valve oscillators will work as is with simply lower HT with an N-channel depletion FET. An exception would be pure Tetrode (not the Pentode like Beam Tetrode) oscillators using the negative resistance just past the knee or kink. Hence the KT prefix on many US Beam Tetrodes for "Kinkless Tetrode".
Op-amps and double balanced multipliers (Gilbert cell like) also developed and explained in the valve era.
Almost all the valve oscillators will work as is with simply lower HT with an N-channel depletion FET. An exception would be pure Tetrode (not the Pentode like Beam Tetrode) oscillators using the negative resistance just past the knee or kink. Hence the KT prefix on many US Beam Tetrodes for "Kinkless Tetrode".
