looking for a scope with frequency readout etc - Page 1
Forum section: electronics / beginners

author: m3vuv
author_rank: Super Contributor
timestamp: October 17, 2021, 11:51:55 am
content: Hi all,i am after getting sommat like a 100+ bw scope with readouts like frequency readout and p 2 p values etc,would prefer a tektronix but dont know what models to look for,dont care if its analog or dso,any ideas what to look for,crt is fine,tia m3vuv.

author: IDEngineer
author_rank: Super Contributor
timestamp: October 17, 2021, 04:29:41 pm
content: Most digital scopes include such measurement functions, even entry level units. It's probably hard to find one without them these days.

author: rstofer
author_rank: Super Contributor
timestamp: October 17, 2021, 04:53:54 pm
content: The Rigol DS1054Z certainly has that capability and can be unlocked to 100 MHz.Any of the Siglent offerings will also do that. SDS1104X-E would be my choice. I believe it can be unlocked to 200 MHz - check around. Otherwise, the SDS1204X-E is a nice 200 MHz scope.There are LOTS of 'what scope to buy' threads here and over in Test Equipment. Maybe 'Search' will help

author: David Hess
author_rank: Super Contributor
timestamp: October 17, 2021, 05:54:30 pm
content: If you are referring to frequency measurement of the same caliber that a dedicated frequency counter would provide, than almost all DSOs fail for lack of precision and accuracy, only providing rudimentary performance.Ignoring mainframe instruments like the 11k series, the Tektronix oscilloscopes which included built in frequency measurement are the 2247, 2252, and 2236. They are actually better than most frequency counters since they include gated reciprocal frequency measurement comparable to a high end universal counter.The Tektronix 2465 series of oscilloscopes also had a frequency counter option but I am not familiar with it.

author: james_s
author_rank: Super Contributor
timestamp: October 17, 2021, 06:14:50 pm
content: I've never seen a DSO that didn't have basic on-screen measurements for things like frequency, peak to peak and RMS voltage, duty cycle, etc. They may have existed but not anything I've ever used. Most analog scopes do not have anything like this, the closest I've seen are cursors that can be manually placed and display the values.

author: Electro Fan
author_rank: Super Contributor
timestamp: October 17, 2021, 08:02:57 pm
content: It might depend on how how many digits you want displayed and much accuracy you want from the oscilloscope's counter. (Resolution and accuracy are of course two different things.)I have a Tektronix 2247A - it is a great analog scope with a counter. On it's own the counter is not so accurate. Maybe someone with David Hess' skill could make it more accurate. But it happens to have an input for a 10 MHz reference signal, so when the ref input is driven by a GPDSO the counter becomes reasonably accurate (roughly 1 Hz on 100 MHz). My 2467B also has a counter (not super accurate either) but no 10 MHz ref input. (Again to be fair, like the 2247A the 2267B is old and maybe it could do better with a tune up). On my 2000 series Rigol (which has no ref input) the counter is nothing to write home about for high frequencies (for 10 MHz it shows 10.0000 MHz - not a lot of digits displayed). On the other hand with a signal of 10,000.1 Hz the Rigol shows 10.000.1 kHz. Net, net: I think unless you have a pretty good scope there are better ways to get accurate frequency counting, but if you don't want a lot of resolution and/or just want to be in the ball park it should be an easy to find feature on a lot of scopes.

author: Electro Fan
author_rank: Super Contributor
timestamp: October 17, 2021, 08:52:05 pm
content: In re-reading the original post it looks like the OP wants statistics (numerical measurements), not just frequency counting. On analog Tektronix scopes the models David Hess listed would be the likely candidates. On almost any recent digital scope there will likely be many statistics and related (cursor) measuring features. Just depends on the specific requirements.

author: Wallace Gasiewicz
author_rank: Super Contributor
timestamp: October 17, 2021, 09:27:01 pm
content: My Agilent 54810 digital scope has more functions than I can use, but I am using more and more each day. The freq counter is pretty good but limited by the poor little frequency reference in the scope. There is no input for a better freq standard either. Maybe I will look at the boards and see if there is an easy way to install an input for a 10 MHz freq standard.Just some things to think about.Any freq readout is only as good as the standard it uses.Wally

author: radiolistener
author_rank: Super Contributor
timestamp: October 17, 2021, 11:29:32 pm
content: almost all oscilloscope has such feature, except very old analog tube oscilloscope.

author: rstofer
author_rank: Super Contributor
timestamp: October 18, 2021, 12:23:53 am
content: The frequency counter spec for the DS1054Z:Frequency Accuracy100 ppm (lower than 10 kHz)50 ppm (higher than 10 kHz)Page 7https://assets.testequity.com/te1/Documents/pdf/rigol/Rigol-DS1054Z-Specification.pdf

author: vk6zgo
author_rank: Super Contributor
timestamp: October 18, 2021, 04:02:12 am
content: Quote from: radiolistener on October 17, 2021, 11:29:32 pmMany old analog Oscilloscopes go one better, as they make the vertical output available to feed to arealfrequency counter!

author: David Hess
author_rank: Super Contributor
timestamp: October 18, 2021, 09:27:48 pm
content: Quote from: Electro Fan on October 17, 2021, 08:02:57 pmThe built in frequency reference Tektronix used was not very good, but an external reference can be used which greatly improves the accuracy. Or I know of at least one person who installed a much better TCXO or OCXO reference.QuoteThe 2467B series all include a very basic and low performance built in counter, but also had an optional high performance counter more like the 2247A.Quote from: vk6zgo on October 18, 2021, 04:02:12 amThat is essentially what Tektronix did with their 2247A and 2236 series, except they included a reciprocal universal counter with an input from a trigger channel, and tied the counter's arm input to the B timebase so gated measurements can also be made.

author: IDEngineer
author_rank: Super Contributor
timestamp: October 18, 2021, 09:45:44 pm
content: Based on the OP's verbatim statement that:Quote...my interpretation is that the measurement features of even the entry level DSO's will more than suffice for their purposes. Can you get more accuracy or resolution with other instruments? Absolutely. But something about the way that question is phrased makes me think an entry level DSO will get his job done.