Plenty has been written about this oscilloscope, the venerable and grand Tektronix 2465 4 channel 300MHz Oscilloscope. I do not intend to clutter the space. This page is just a log of the issues I faced and solving them
First, The manual is available free of charge at http://bama.edebris.com/manuals/tek/2465/
Issue # 1: Waveform display is pulsing. It is as if the CRT dot moves from left to right while tracing out the sine wave input. It is like an ECG screen. I want a steady waveform display
The applied frequency is probably too low in the range of Hz. This should not happen for higher frequencies in the range of KHz
Issue # 2: Oscilloscope channel has DC offset. The input waveform is at zero DC, but the scope shows it as having some offset. The scope itself has some internal offset. When you apply a ground coupling, you see that it is ground coupled at 200mV. Why is this? Can this be changed?
Issue # 3: Can't see other channels
That's what the mode buttons are for. You need to press the knobs for the respective channels to see the waveforms for that
Issue # 4: Signal not triggering on channel X
If only channel X is on, then Channel X must be the trigger source. Make sure Channel X is set to the source on the trigger menu.
Function Generator
You might have a similar issues with the function generator from time to time. I am using a GW instek GFG-8020H function generator
1. The triangle waves look like sawtooths
2. The square looks like pulse.
No matter how much I adjust the duty cycle knob, I cannot get the square to look like a square or a triangle to look like a triangle. Also the square seems to have some overshoot followed by first order settling indicating some sort of stability feedback loop issue. Finally the sine wave looks distorted. The 2nd harmonic is 10% of the fundamental.
I used high frequency cables and probes, but it stays the same. So does not look like a probe or loading issue. Finally, I see that the frequency seems to flicker a bit about +/-2%. Did you encounter anything similar from your function generator? Any clues as to what this could be?
1. The answer is that the function generator is being used at the edge of it's range. If the range setting of the function generator is at 100K, but you have turned the frequency knob so low that you are actually putting out a 5KHz wave, then obviously you are operating the FG at the edge of it's range. When putting out 5KHz, use a 10K range (assuming max freq at 10K range is 20K)
2. Another issue is you may be using an abnormally high offset, saturating the circuit beyond it's point of linearity
3. Finally, take a look at the duty cycle knob. Turn it all the way inside. Don't mess with that knob while looking at Duty cycle. It will screw up the wave
First, The manual is available free of charge at http://bama.edebris.com/manuals/tek/2465/
Issue # 1: Waveform display is pulsing. It is as if the CRT dot moves from left to right while tracing out the sine wave input. It is like an ECG screen. I want a steady waveform display
The applied frequency is probably too low in the range of Hz. This should not happen for higher frequencies in the range of KHz
Issue # 2: Oscilloscope channel has DC offset. The input waveform is at zero DC, but the scope shows it as having some offset. The scope itself has some internal offset. When you apply a ground coupling, you see that it is ground coupled at 200mV. Why is this? Can this be changed?
Issue # 3: Can't see other channels
That's what the mode buttons are for. You need to press the knobs for the respective channels to see the waveforms for that
Issue # 4: Signal not triggering on channel X
If only channel X is on, then Channel X must be the trigger source. Make sure Channel X is set to the source on the trigger menu.
Function Generator
You might have a similar issues with the function generator from time to time. I am using a GW instek GFG-8020H function generator
1. The triangle waves look like sawtooths
2. The square looks like pulse.
No matter how much I adjust the duty cycle knob, I cannot get the square to look like a square or a triangle to look like a triangle. Also the square seems to have some overshoot followed by first order settling indicating some sort of stability feedback loop issue. Finally the sine wave looks distorted. The 2nd harmonic is 10% of the fundamental.
I used high frequency cables and probes, but it stays the same. So does not look like a probe or loading issue. Finally, I see that the frequency seems to flicker a bit about +/-2%. Did you encounter anything similar from your function generator? Any clues as to what this could be?
1. The answer is that the function generator is being used at the edge of it's range. If the range setting of the function generator is at 100K, but you have turned the frequency knob so low that you are actually putting out a 5KHz wave, then obviously you are operating the FG at the edge of it's range. When putting out 5KHz, use a 10K range (assuming max freq at 10K range is 20K)
2. Another issue is you may be using an abnormally high offset, saturating the circuit beyond it's point of linearity
3. Finally, take a look at the duty cycle knob. Turn it all the way inside. Don't mess with that knob while looking at Duty cycle. It will screw up the wave
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