Does anyone know the correct name for the 2 transistor LC oscillator that looks like a long tailed pair?
I though it was a Franklin oscillator - the google hits are ambiguous to say the least, but its possible I have the name wrong.
Thanks for any help.
I'm not sure that all the variants have names. Most of the oscillators got names back in the teens and twenties before there was a unified theory of feedback in circuits, and when sustained radio oscillation was a Really Astonishing Thing.
I avoid oscillator type names like the plague... does nothing but add confusion. ...Jim Thompson
The oscillator I have in mind, I could almost draw from memory.
But I'd like some point of reference so I can google for more info.
I've seen them called differential pair oscillators. That what you're looking for?
Dave M
Differential oscillators...
...Jim Thompson
Am 20.01.2016 um 19:59 schrieb Ian Field:
maybe Buttler osc.?
Jorgen
Emitter coupled oscillators? Current-steering oscillators?
Advantage that they don't disturb the power supply very much?
[snip]
Yes ;-)
Yes.
Easy to make sure they self-start.
Easy to AGC (actually energy control) for high spectral purity...
...Jim Thompson
Right, just basicallly inject the AGC control voltage into the current source driving the tail current.
I think I built a little AM transmitter many years ago that worked that way - long tail pair with a crystal/LC positive feedback loop and the audio modulation driving the current source, then buffered with an emitter follower and LC antenna matching network. Seemed to work pretty good...
Why didn't you do that for us? Like, contribute?
No need - it was one of the first things I tried.
Getting the name I thought it was totally wrong didn't help of course.
Its actually a Butler oscillator, and series fed is the variant I need. There are several references in my personal stash library - but it took over an hour of inspecting files to find them.
Turns out I was thinking of totally the wrong name - its a Butler oscillator I needed.
Did eventually find it - the Butler oscillator.
Its the common base stage that drives the LC with high impedance - so very low loading.
The other stage is common collector - so I'm hoping the transistors I picked are fast enough.
That's the one.
It took over an hour sifting through my personal stash library to find it though!
Thanks.
That had already been tried and didn't produce the required result.
Because I eventually found it in my personal stash library, and someone posted the right answer next day as well.
Admittedly my question was a bit vague - but it sorts out who's smart and who's less so.
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