Anybody have a simple schematic for a frequency standard to check to make sure your frequency counter is dead nuts? Thanks
Hmm well it doesn't make much sense to buy a peice of equitment that costs more to check then the peice of equitment you are trying to check. I just heard you buy a 10 dollar crystal and make a frequency standard to make sure your counter is on target. No? gotta buy a 500 dollar standard?You can't simply build one that is accurate enough to do what you want. How do you know if it is stable enough and on frequency until you check it? What do you check it with if you are wanting to check your counter? Frequency standards are lab quality pieces of equipment. You can however buy a rubidium standard but they are not cheap.
http://www.ebay.ca/sch/i.html?_from...RS0&_nkw=rubidium+frequency+standard&_sacat=0
"The next step is to make sure that your test equip. is calibrated correctly. you can have this done somewhere, or you can build a frequency standard for very cheap. the most expensive part is the crystal, and they are like $10. i'll try to draw up a diagram, but for now, do the search thing for "frequency standard" and build any of the circuits you find. this neat little device will put out a singal that is exactly, say, 10mhz.Hmm well it doesn't make much sense to buy a peice of equitment that costs more to check then the peice of equitment you are trying to check. I just heard you buy a 10 dollar crystal and make a frequency standard to make sure your counter is on target. No? gotta buy a 500 dollar standard?
Paid ~$130 for a used rubidium clock from ebay, and had to build a dual voltage power supply in order to power it. Few of the guys here on this forum have a rubidium unit to keep their counters honest.Hmm well it doesn't make much sense to buy a peice of equitment that costs more to check then the peice of equitment you are trying to check. I just heard you buy a 10 dollar crystal and make a frequency standard to make sure your counter is on target. No? gotta buy a 500 dollar standard?
"The next step is to make sure that your test equip. is calibrated correctly. you can have this done somewhere, or you can build a frequency standard for very cheap. the most expensive part is the crystal, and they are like $10. i'll try to draw up a diagram, but for now, do the search thing for "frequency standard" and build any of the circuits you find. this neat little device will put out a singal that is exactly, say, 10mhz.
so you look at you freq. counter and it says, 10.0005. you find the calibration screw inside, and turn it slowly until the counter reads exactly 10.0000mhz. again, they are easy to build. " soo where is the diagram, por fa vor
Google is my first choice and when I don't comprehendo I ask all my friends on worldwidedx. That's what forums are for right?WWV N. I. S. T.
https://www.nist.gov/time-and-frequency-services/nist-radio-stations/wwv
Use Google, Bing or some other search engine to find the answer to almost any question.
10-4 thanks mikeYou can use TCXO. 0.5ppm @10MHz is good enough to calibrate frequency counter.
Mike
10-4 thanks mike
1) If you use WWV; that will work. But you need a Ham radio to use to make that happen. ~$500?Google is my first choice and when I don't comprehendo I ask all my friends on worldwidedx. That's what forums are for right?
In addition, having /using a rubidium 'clock' is the only other alternative. They are accurate within +/- .1 hz and have a long lifetime (six years - IIRC) and do not require calibration. They are what is used for calibration, since they are very close to being an atomic clock in their own right.You don't need a frequency standard, but you will need to get your counter calibrated by a certified facility at least once or twice per year (as specified by the counter manufacturer). This certified facility will have its own lab standards properly calibrated to a higher degree of accuracy, and they should provide documentation that is traceable to the National Institute of Standards and Technology (NIST), which used to be called the National Bureau of Standards.
If YOU owned the frequency standard, YOU would have to have it calibrated and adjusted/repaired regularly. That would be much more expensive than having a bench grade (not laboratory grade) counter. But it will still involve periodic calibration. So will all the instruments you use: voltmeters, ammeters, o'scopes, signal generators.... Otherwise, you can't be sure of what you think you have.
In most situations the calibration standard has to be calibrated twice as often as the device you are calibrating. Oscilloscopes in most cases are used just for observation and not for adjusting critical frequency or voltage measurements. For frequency measurements you use the Frequency counters. Voltages use a calibrated DVM or equivalent.If YOU owned the frequency standard, YOU would have to have it calibrated and adjusted/repaired regularly. That would be much more expensive than having a bench grade (not laboratory grade) counter. But it will still involve periodic calibration. So will all the instruments you use: voltmeters, ammeters, o'scopes, signal generators.... Otherwise, you can't be sure of what you think you have.