UK Vintage Radio Repair and Restoration Discussion Forum - View Single Post - Non-working Commodore PET 3016

SiriusHardware · 25th Feb 2021, 7:20 pm

Well, first I need to modify the request for the Volts / Div figure - I thought your screen was 10 divisions high, not 8, so the best Volts / Div setting for both channels will be 2V / Div rather than 1V / Div as I said earlier.

Just to go briefly through some oscilloscope basics - sorry if you already know this.

The faint squares made from dotted lines on the screen are the 'divisions' referred to on the settings for the 'horizontal' and 'vertical' knobs.

If you have the Vertical Volts / Division control set to '1V / Div', that means that each faint square going up or down the screen represents one Volt. Looking at your signal in the previous post, with the 'Vertical' setting at 1V / Div, your signal is a little over four divisions high, so your signal is a little over four Volts high.

The divisions going across the screen represent time, and the Horizontal 'Time/Div' setting determines how much time each division represents, typically in milliseconds or microseconds. In your previous post you have this set to 100mS / Division, not 20uS. Try changing it to 20uS (if that is one of the choices available) and see what that looks like.

25th Feb 2021, 7:20 pm	#672
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,586	Re: Non-working Commodore PET 3016 Well, first I need to modify the request for the Volts / Div figure - I thought your screen was 10 divisions high, not 8, so the best Volts / Div setting for both channels will be 2V / Div rather than 1V / Div as I said earlier. Just to go briefly through some oscilloscope basics - sorry if you already know this. The faint squares made from dotted lines on the screen are the 'divisions' referred to on the settings for the 'horizontal' and 'vertical' knobs. If you have the Vertical Volts / Division control set to '1V / Div', that means that each faint square going up or down the screen represents one Volt. Looking at your signal in the previous post, with the 'Vertical' setting at 1V / Div, your signal is a little over four divisions high, so your signal is a little over four Volts high. The divisions going across the screen represent time, and the Horizontal 'Time/Div' setting determines how much time each division represents, typically in milliseconds or microseconds. In your previous post you have this set to 100mS / Division, not 20uS. Try changing it to 20uS (if that is one of the choices available) and see what that looks like.