Please check if this is the real F199C

szttg

Please check if this is the real F199C [Copy link]

I received a second-hand Fluke F199C. The software version is F199C 07.02. I used it to measure a 50M square wave, but only saw a sine wave. I'm a little suspicious whether it was modified from F196C. I took it apart and took a look, and took a picture. Please take a look, is it F199C?

strong161

The F190C series are all for medical use, most of them are from medical schools, many of them are not used much and are scrapped after being stored for a long time. If you have connections, you can basically get one for 100 or 80 yuan. If you want to convert a good 196 to 199, the cost is high and the risk is high, and the return is low. I don't know where the impulse is...

szttg

Thanks for the reply. This machine is quite new, with almost no signs of use on the outside. After opening it and carefully looking at the circuit board, no signs of repair were found. It is working normally now. I just don't understand why the 50M square wave becomes a sine wave. According to my understanding, there should be no problem with the 200M bandwidth showing at least 3 times the harmonics.

tianshuihu

szttg posted on 2018-11-22 10:08 Thanks for the reply. This machine is very new. There are almost no signs of use on the outside. After opening it and carefully looking at the circuit board, there are no signs of repair. Currently...

How do you measure the 50M square wave signal? If the oscilloscope turns on the input bandwidth limit, the square wave will become a sine wave, and the amplitude will also decrease

szttg

tianshuihu posted on 2018-11-22 13:43 How do you measure a 50M square wave signal? If the oscilloscope has input bandwidth limit turned on, the square wave will become a sine wave, and the amplitude will also decrease

Make sure there is no bandwidth limit, turn on Full