You can use 74HC390, or 74HC4017 as decade counters. The 74HC means they are specced to work up to around 30MHz. It is also possible to program many ublox GPS units to output their PPS at a higher Hz than 1. Although their signal can be a bit jittery at some Mhz values (I believe from having to freq synth from their own clock), you can work with 10khz or 100khz or 1Mhz I believe and get a nice signal out of them without having to divide other signals to get use out of the 1Hz PPS.
3:55 Caption on screen: "to the nearest quarter hertz" Huh? The counter display is displaying only unit hertz, so the display is inherently to the nearest HALF hertz. What am I missing ? Why "quarter" ?
Hi, I'm interested in the GPS based counter and reference, is that home made or bought? I want to calibrate several of my instruments and although I have a rubidium standard oscillator it has a calibration control and label telling me when it was last calibrated. The calibration date was several years ago and I don't know how accurate it really is now. it seems to function ok and my HP microwave frequency counter shown it is accurate to a Hz or so. What should I believe. I also have an RF frequency generator that was calibrated recently. What would you trust? the rubidium standard or the calibrated generator to be more accurate as there is a slight discrepancy of about 1-2Hz in all of the equipment compared to the Rubidium standard. Should I just calibrate everything to the Rubidium oscillator?
Hello. The GPS disciplined frequency counter is homebrew. The original project was described on this page: www.lloydm.net/Demos/GPS_freq_counter.html, and a revision using surface mount components here: www.lloydm.net/Demos/smd.html. I can’t really advise on the relative merits of different instruments or measurement approaches; however, to the best of my knowledge GPS is the most accurate time interval source accessible to amateurs for high frequency counting. 73, WA4EFS
Thank you for very interesting video! Quality of your diy devices is adorable!
You can use 74HC390, or 74HC4017 as decade counters. The 74HC means they are specced to work up to around 30MHz.
It is also possible to program many ublox GPS units to output their PPS at a higher Hz than 1. Although their signal can be a bit jittery at some Mhz values (I believe from having to freq synth from their own clock), you can work with 10khz or 100khz or 1Mhz I believe and get a nice signal out of them without having to divide other signals to get use out of the 1Hz PPS.
Thanks Matt. With your permission I'd like to quote those suggestions in the write-up page (with attribution, of course).
3:55 Caption on screen: "to the nearest quarter hertz" Huh? The counter display is displaying only unit hertz, so the display is inherently to the nearest HALF hertz. What am I missing ? Why "quarter" ?
Duration is 4 seconds.
Hi, I'm interested in the GPS based counter and reference, is that home made or bought?
I want to calibrate several of my instruments and although I have a rubidium standard oscillator it has a calibration control and label telling me when it was last calibrated.
The calibration date was several years ago and I don't know how accurate it really is now. it seems to function ok and my HP microwave frequency counter shown it is accurate to a Hz or so.
What should I believe. I also have an RF frequency generator that was calibrated recently. What would you trust? the rubidium standard or the calibrated generator to be more accurate as there is a slight discrepancy of about 1-2Hz in all of the equipment compared to the Rubidium standard. Should I just calibrate everything to the Rubidium oscillator?
Hello. The GPS disciplined frequency counter is homebrew. The original project was described on this page: www.lloydm.net/Demos/GPS_freq_counter.html, and a revision using surface mount components here: www.lloydm.net/Demos/smd.html. I can’t really advise on the relative merits of different instruments or measurement approaches; however, to the best of my knowledge GPS is the most accurate time interval source accessible to amateurs for high frequency counting. 73, WA4EFS
@@lloydsdemos7366 Thank you, I'll check that out.
GPSDOs are available online, under $100.