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I have incomplete details of a very interesting RCCR oscillator circuit that, back in 1960, used just 3 transistors as the amplifier. In those days, the transistors were germanium PNP, almost certainly. I cannot see how just 3 transistors can do that, because the circuit requires to be driven in push-pull with some gain on the in-phase (push) side. I need suggestions how to do that, using Si transistors, of course. The frequency range I need is 20 kHz to 60 kHz. In this range, ordinary op-amps can introduce unwanted phase-shifts unless the closed-loop gain is kept very low.

I am including the original article and the results of a Spice simulation. Original article Spice simulation

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    \$\begingroup\$ expand your zip locally, then attach any picture files, or if necessary screenshots of your display \$\endgroup\$
    – Neil_UK
    Commented May 26, 2022 at 11:20
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    \$\begingroup\$ John Woodgate - Hi, (a) As just commented, please edit your question & upload relevant image files (use Ctrl+G in the edit box, on a PC). If you reach the limit (2 files?) for a new user, then put them on a public share somewhere and some kind person will edit them into your question for you. (b) Please also add a clear question. Are you trying to understand how the circuit works? Or are you trying to build it (without germanium transistors?) and have a problem doing that? Please try to be as specific as possible about the question, and include any relevant context & constraints. Thanks. \$\endgroup\$
    – SamGibson ♦
    Commented May 26, 2022 at 11:27
  • \$\begingroup\$ Thanks, Neil, but I don't know how to atatch, as i said. \$\endgroup\$
    – John Woodgate
    Commented May 26, 2022 at 13:02
  • \$\begingroup\$ Thanks, Sam. I can reduce to 2 files and do as you say. I thought my message was clear: I don't see how to make a 3-transistor amplifier that will produce 2 anti-phase outputs, the in-phase one being a little larger. I will use Si transistors, of course. When I see a circuit that does that, I will build it. \$\endgroup\$
    – John Woodgate
    Commented May 26, 2022 at 13:06

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