MSO2024B Oscilloscope problems - Page 1
Forum section: electronics / testgear

author: tan_yc
author_rank: Newbie
timestamp: February 09, 2015, 07:24:31 am
content: I newly bought a Tektronix MSO2024B oscilloscope. Upon power up, I tested the probes with the "Probe Comp" signal. According to the User Manual, the (squarewave) signal should be 5V and 1kHz. However, the recorded frequency value on the screen is 986.xxxHz instead of 1kHz.The error rate is more than 1%.Is this normal? Any problems with this scope?I got a TDS1001B and the "Probe Comp" gives 1.00000kHz on the screen.Kindly advise.

author: EV
author_rank: Frequent Contributor
timestamp: February 09, 2015, 07:33:28 am
content: Quote from: tan_yc on February 09, 2015, 07:24:31 amYes, it is normal. It is not exactly 1 kHz. It is only meant to adjust the probe compensation.

author: tautech
author_rank: Super Contributor
timestamp: February 09, 2015, 07:37:54 am
content: They vary all over the place, old scopes had adjustment to set them dead on 1 KHz.New DSO's are generelly within a few 100ths of a Hz.

author: w2aew
author_rank: Super Contributor
timestamp: February 09, 2015, 03:04:50 pm
content: Quote from: tan_yc on February 09, 2015, 07:24:31 amIt is NOT intended to be a frequency reference or a voltage reference. It is only designed to be used for compensating the probes - thus is only a basic square wave. What you are seeing is perfectly normal and acceptable.

author: timb
author_rank: Super Contributor
timestamp: February 10, 2015, 10:07:11 pm
content: Just checked my MDO2024B; it's around 1.05KHz, so 0.5% out. It's normal. So long as the square wave has clean, sharp edges you're fine. It's only meant to compensate the probes.Sent from my Smartphone

author: EV
author_rank: Frequent Contributor
timestamp: February 10, 2015, 10:57:48 pm
content: Quote from: timb on February 10, 2015, 10:07:11 pmI think it is 5% out.

author: tan_yc
author_rank: Newbie
timestamp: February 11, 2015, 02:10:18 am
content: I have tried on other scopes and they produce 1kHz square wave signals for this compensation signal. This is the only scope that I get a signal which is quite far from 1kHz. Even Agilent and Lecroy scopes give a signal with error rate about or less than 0.1%.

author: w2aew
author_rank: Super Contributor
timestamp: February 11, 2015, 03:45:02 am
content: Quote from: tan_yc on February 11, 2015, 02:10:18 amAccording to the spec for this scope, the compensation signal amplitude is spec'd to +/-10% for amplitude, and +/-25% for frequency. So, there is absolute nothing wrong with the scope, or this signal.

author: timb
author_rank: Super Contributor
timestamp: February 12, 2015, 04:03:49 am
content: Quote from: tan_yc on February 11, 2015, 02:10:18 amMaybe the Tek's frequency counter is just more accurate and the other scopes are lying. Did you ever think of that?Seriously, it's meant to produce a square wave with clean edges. It could be 500Hz or 5KHz, it doesn't matter. It's there to compensate your probes only. That's it.Sent from my Smartphone

author: Lunasix
author_rank: Regular Contributor
timestamp: February 17, 2015, 02:12:02 pm
content: Dont 'worry ! I confirm : on my MSO2024, I have 934Hz (same result with a frequency counter).