Hello time enthusiasts! I'm hoping for your advice on my (perhaps modest, by this list's standards) project.
I would like to make a frequency calibration of a 10 MHz oscillator to 1 ppm (1E-6) or better, using some basic equipment. I do not have a GPSDO or any serious lab equipment, or budget for same as this is just a personal project. What I do have access to: 10 MHz uncalibrated TCXO (K1602TE in 14-pin DIP can from online auction site) Optoelectronics 3000A+ frequency counter (I believe stable to < 1 ppm, but not recently calibrated) Sony ICF-2010 shortwave radio (consumer item, possibly stable at 1 ppm level) Tektronix TDS220 (basic digital scope) Saleae Logic analyzer (software-defined logic analyzer, the datalogger part has generic 24 MHz xtal) PC running Windows XP Is it possible to calibrate my 10 MHz oscillator to some standard reference source at the 1 ppm level using these tools? I also have a PIC programmer so I could construct a decade divider chain, etc. if that was useful. So far, directly counting the 10 MHz signal using a 10 sec gate, the count varies about +/- 1 Hz (0.1 ppm) over several hours of measurement. However, I don't know if the oscillator or the counter drifts more, or if either one is close to being accurate. My first try at a standard reference was to monitor the WWV broadcast at 5 MHz, pipe the output into the PC and view it with DL4YHF "Spectrum Lab". I found the WWV signal wandered around over 10 Hz (2 ppm) during the night and faded at sunrise without ever stabilizing, so that doesn't seem too encouraging. I don't know if there are any stable signals in groundwave range. I've read about using an analog TV horizontal flyback signal when locked to a network broadcast, but I'm just a bit too late for that technique to work! Likewise with the Loran-C receiver a guy at a local ham club has. I assume any accessible signals on my HDTV are internally synthesized with dubious accuracy. I have DSL on my phone line, but I don't know if there's any useful standard frequencies there and I don't think I'm supposed to directly probe the phone line anyway. Comparison to a GPS frequency standard would obviously work and since I live in Mountain View, CA there's probably some within walking distance, but I don't know anyone in the metrology community. Thanks for any suggestions or insights into this question! John Beale N8JUF _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
