The sample, calibration square wave of an old oscilloscope is operational, but shows spikes and reduced amplitude. I suspect that the input resistor is fried. I seem to remember the standard impedance was 1 Meg ohm and that the ersistor is in parallel with a capacitor. Any chance someone will sahke my memory and tell me the the general value? IT has been 20 years and I need more than just a pair of new glasses to go behind the case screw. Trace "A" works fine. I am not too lazy to look, just want to know if the symtoms put me in the ballpark. Thanks! I'm new here so please forgive my lack of 'smarts.'
Dual Trace Oscilloscope Input
in Electronics chit chat
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The sample, calibration square wave of an old oscilloscope is operational, but shows spikes and reduced amplitude. I suspect that the input resistor is fried. I seem to remember the standard impedance was 1 Meg ohm and that the ersistor is in parallel with a capacitor. Any chance someone will sahke my memory and tell me the the general value? IT has been 20 years and I need more than just a pair of new glasses to go behind the case screw. Trace "A" works fine. I am not too lazy to look, just want to know if the symtoms put me in the ballpark. Thanks! I'm new here so please forgive my lack of 'smarts.'