Oh. Timebase was actually set to full CCW. Multiplier was at 1x. I think I set the timebase to that so that I could view in on <100hz frequencies without having the screen flicker so much but I dont think it helped any. Timebase is set to cal now.
I got differential mode to work. Shows about a 9v square wave on screen probing Source and Gate. I previously found similar square wave when setting one probe to AC coupling on gate. The differential way DC coupled shows the square wave's bottom on the X-axis.
I got differential mode to work. Shows about a 9v square wave on screen probing Source and Gate. I previously found similar square wave when setting one probe to AC coupling on gate. The differential way DC coupled shows the square wave's bottom on the X-axis.
Both channels need to be set to DC coupling.
In AC mode, you can't tell if the waveform is driving back to ground.
In differential mode, you can get high resolution waveforms even if they have significant DC offset.
Are both the high and low-side waveforms driving back to the reference line?
In AC mode, you can't tell if the waveform is driving back to ground.
In differential mode, you can get high resolution waveforms even if they have significant DC offset.
Are both the high and low-side waveforms driving back to the reference line?
Im going to say YES to that question, but I dont trust differential mode on this scope as I do not think Invert button is working correctly. When I press Invert even with the probes disconnected from the scope the trace line jumps off axis by about 3/4". Everything else seems calibrated when not activating invert.
I can see the 10v square wave on the gate pads both high and low sides.
High side doesn't need differential mode to observe the 0-10v square wave as source is 0vDC which is the same as amp's ground and amp's positive speaker terminal.
Low side, I see a 10v square wave on AC coupling, but in differential mode its off the X-axis I believe on account of my invert feature not working correctly on channel 1. Using my DVM, I get 4.5v on gate pad referencing source pad and so I can probably determine the waveform is falling back to reference on account of that reading.
I can see the 10v square wave on the gate pads both high and low sides.
High side doesn't need differential mode to observe the 0-10v square wave as source is 0vDC which is the same as amp's ground and amp's positive speaker terminal.
Low side, I see a 10v square wave on AC coupling, but in differential mode its off the X-axis I believe on account of my invert feature not working correctly on channel 1. Using my DVM, I get 4.5v on gate pad referencing source pad and so I can probably determine the waveform is falling back to reference on account of that reading.
12v attached to both probes. ch1 probe ground to negative. Both probes at 1x.
INV1 button only inverts ch1.
There seems to be no INV2 feature on this scope.
5V/Div.
1. First photo with 1 line, is actually traces from BOTH channels at the same point at +12v.
2. Second photo shows CH1 inverted with INV1 pressed. You can see the invert function is not operating correctly as the trace for CH1 is only at -6 where it should be at -12.
3. third photo is the differential reading. This should have been 0v but since CH1 in not inverted correctly its showing +6v
INV1 button only inverts ch1.
There seems to be no INV2 feature on this scope.
5V/Div.
1. First photo with 1 line, is actually traces from BOTH channels at the same point at +12v.
2. Second photo shows CH1 inverted with INV1 pressed. You can see the invert function is not operating correctly as the trace for CH1 is only at -6 where it should be at -12.
3. third photo is the differential reading. This should have been 0v but since CH1 in not inverted correctly its showing +6v
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OK here it is correct. Also 1,2,3 of the second set is actually positive not negative.
U201 WITH 6&7 jumped on U200
1. 0.080 flat
2. 0.020
3. 0.020
4. -15.4
5. 0.02
6. 0.02
7. 0.02
8. 15.2
U201 with U200 6&7 NOT jumped
1. 3.925 flat
2. 0.354
3. 0.354
4. -15.4
5. 0.018
6. 0.018
7. 0.018
8. 15.4
U201 WITH 6&7 jumped on U200
1. 0.080 flat
2. 0.020
3. 0.020
4. -15.4
5. 0.02
6. 0.02
7. 0.02
8. 15.2
U201 with U200 6&7 NOT jumped
1. 3.925 flat
2. 0.354
3. 0.354
4. -15.4
5. 0.018
6. 0.018
7. 0.018
8. 15.4
