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- Hacker News
- Was just talking about frequency references last night -- the ARRL Frequency Measurement Test is this Thursday eveningby swalberg
- interesting teardown, thanks.
for homelab application where extra space & power consumption is not a real concern, "temperature resistance" (tempco) is no longer relevant. you can get a constant temperature controller with +/- 0.01 degree range kind of spec for $65. verified using a reputable digital temperature sensor (outside the control loop) and the performance is pretty solid.
by tw1984 - out of interest, what would the physical setup look like? Hard to imagine you could achieve isotropic temperature approaching +/- 0.01 degree over the size of a typical PCB.by RossBencina
- I believe it.
This DIY GPSDO has a self-heating PCB to keep the temperature constant: https://www.paulvdiyblogs.net/2023/06/gpsdo-version-4.html?m....
It’s a long blog post, but in the August 24, 2023 update, he mentions that the PCB temperature stays rock solid at 52.9C.
by tverbeure - A fun tidbit about crystal oscillators is that they allowed “un-tethered” sound recording on motion picture film cameras. If both your sound recorder and your film camera are using a crystal oscillator as a reference for their motors - you can sync them up in post without needing them to be physically connected during filming.by kamranjon
- I imagine that the accuracy requirements for those crystals are not quite as stringent as the one that I’m talking about here!by tverbeure