w2aew | #203: Schmitt Trigger Oscillator revisited | TDR | Measure Capacitors and Inductors @w2aew | Uploaded June 2015 | Updated October 2024, 7 hours ago.
This video revisits a 74AC14 Schmitt Trigger Oscillator project that was used for several videos including a TDR (time domain reflectometer) as well as measuring unknown capacitors and inductors. The reason for revisiting this circuit is because a viewer (Marcus Jenkins - EA5IGC) sent me a copy of the board he designed, and I wanted to show him how it performs compared to my original prototype. Here are links to the videos and blog that I mention in this video:
My initial video on the schmitt trigger oscillator:
youtube.com/watch?v=NuXitMK3HSA
My video on a cheap TDR using this oscillator:
youtube.com/watch?v=9cP6w2odGUc
My original video on TDR (uses a signal generator, but theory is same):
youtube.com/watch?v=Il_eju4D_TM
Measuring unknown capacitors and inductors:
youtube.com/watch?v=74fz9iwZ_sM
Measuring coax velocity factor and impedance:
youtube.com/watch?v=TpIIftvQPFM
Marcus' blog on this PCB project:
bit.ly/1ANeKWH
Link to order your own boards:
bit.ly/1MgU9wA

Note - my iPad case/stand is by ZooGue - very nice high quality, stable stand.