Hi,

A good test is to direct connect the 1kHz Calibration signal BNC to channel 1 BNC (a BNC to BNC cable) and see what the waveform looks like. You might need to use a coax T and a terminator.

This will give us a better idea of how much noise is present in the input amplifiers and ADC.

Look at several divisions (at least 4) at 1ms rate. look for similar noise on the top and bottom as shown in the picture above. Then go to the fastest speed that allows a rise time to start at the far left graticule and end near the middle (5th) graticule. Check the edge for non-monotonicity (the edge rises and then is stepped or falls, then rises again. There also should not be Overshoot (the ringing you see in your video).

If you see any of these anomolies, you might need to set the input impedance to 50 Ohm. Some scopes will only allow 5 Volt maximum input voltage though, make sure it will handle it. There should be NO waveform anomolies with the 50 Ohm termination.

Clipping the probe ground to the probe tip is a good way to sample the Electromagnetic Environment around a measurement area. You would be surprised what some debug environments look like. It forms a single turn loop probe (similar method as an EMI sniffer probe).

The inductance of the probe ground is really most of overshoot you see in your waveforms (it had better be). The best way to view waveforms is at the receive side and to use a short ground. The smaller the loop area - hence inductance - the more waveform fidelity you will see. If it has a ground ring near the probe tip, get a small spring that fits around the ring and bend one or 2 turns out and shape it for use as a ground for probing. You can see the difference easily by probing activity on the 74LVX74 chip pin 5, 6, 8 or 9 with the probe tip and use the spring ground you made to connect to pin 7. Capture the waveform slow sweep speeds and the fastest that will provide 5 divisions, save it. Then probe using the pin (pin 5, 6, 8, or 9) and use the long ground wire supplied with the probe. You should see all of overshoot go away with the short spring ground and it should return with the long ground.

If you want to see a higher bandwidth signal, the Empeg has some 74LVX and RAM parts that will exceed the bandwidth of the oscilloscope.

Be very careful probing not to short pins.

Ross
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In SI, a little termination and attention to layout goes a long way. In EMC, without SI, you'll spend 80% of the effort on the last 3dB.