08-24-2013, 10:52 AM
The classic tube oscillator uses triode.
The oscillation section of any pentagrid is in fact a triode which plate is the second grid.
So it is in fact better (simpler) using a triode unless you want to eventually convert that thing into a mixing circuit.
Also remember that the two main conditions of oscillation is 1)the gain exceeding unity at the resonant frequency and 2) the feedback being positive.
SO besides the coils you do need some capacitor to form a tank.
You also need the decoupling cap across the power supply, without which the oscillation will not be stable.
It'd be easier if you simply drew the circuit you are trying to assemble, scanned it and placed it here. Then we could comment on your circuit and not make guesses. Otherwise it is kinda blind leading blind situation.
The oscillation section of any pentagrid is in fact a triode which plate is the second grid.
So it is in fact better (simpler) using a triode unless you want to eventually convert that thing into a mixing circuit.
Also remember that the two main conditions of oscillation is 1)the gain exceeding unity at the resonant frequency and 2) the feedback being positive.
SO besides the coils you do need some capacitor to form a tank.
You also need the decoupling cap across the power supply, without which the oscillation will not be stable.
It'd be easier if you simply drew the circuit you are trying to assemble, scanned it and placed it here. Then we could comment on your circuit and not make guesses. Otherwise it is kinda blind leading blind situation.
