Oscillator design

RE: Oscillator design

shabaz — Sun, 08 Jan 2023 20:42:35 GMT

Nice work!

That's actually good results, if you've got your second harmonic down by what looks about 26 dB. It's hard to optimise, it just takes experimentation, swapping out components etc, because LTSpice is only partially useful for oscillator circuits. Component books with loads of pF capacitors helps a lot, just sitting there experimenting all day! The 2N2222 will struggle to reach 10 MHz oscillation, due to limited fT value. The old BF199 NPN transistor is good for experimenting since it is TO92 package, but unfortunately it's hard to find now (it is probably available from ebay etc but they are probably not genuine which doesn't help!). Anyway since you're comfortable with surface-mount, the SOT-23 BFR92P is really nice, well worth getting a few of those for experimentation, and Farnell has loads of them in stock currently although I bet they often run out of those. You'll easily get that to function for 10 MHz operation.

RE: Oscillator design

colporteur — Sun, 08 Jan 2023 16:02:05 GMT

What is your background? What was your educational discipline? What are you doing now? My career after 17 years heavy in electronic support and design took me away to computer systems administration for 20 years. Tens years ago I started reviving the skills and knowledge. I would never rate my knowledge and skill level with a Shabaz. You picked a good project, he is still around to support it.

RE: Oscillator design

dougw — Sun, 08 Jan 2023 15:23:38 GMT

Nice looking probe.