19-11-2017, 11:12 AM
Thanks everyone, especially Mark for his detailed response(s) (and admonishments).
Being a newbie does reflect my ignorance I know but I'm not entirely incompetent either. Both my degrees are in Biology rather than electronics/physics (the maths was a bit above me at the time). It may appear I've taken a scattergun approach to this and others but I'd like to think I have been a bit more focussed than that.
Anyway, the calibration.
Are we talking about the same thing here? On this 'scope on the bottom left of the panel is a small copper protuberance on which one hangs the end of the x10 probe. Pressing the 'cal' button is meant to produce several traces on the screen and one uses a trimmer tool on the probe body to get the traces as they should be (the manual is very good here). Only the focus and intensity controls work at this setting; nothing else does.
I do NOT get ANY traces on the screen. Testing the output on the copper protuberance is meant to show 0.2V; it shows half this, hence my diving into the set to alter the trim pot hoping to see if an increase in voltage produced a trace; it didn't. The circuit for this in-built sig gen seems relatively simple and as there is a cheap-as-chips IC there, that was going to be my first call in the investigation. Unfortunately I'm on holiday for 3+ weeks and did not take the 'scope with me (my wife baulked at the inclusion of a Brompton...she's have gone ballistic if I'd have packed a 'scope as well!).
Obviously I'll investigate further on my return.
I am NOT using the internal trim pots to alter the X/Y settings.
BTW. I've just won an auction for several dilapidated radios which I'm going to use as guinea pigs.
Thanks again,
Richard.
Being a newbie does reflect my ignorance I know but I'm not entirely incompetent either. Both my degrees are in Biology rather than electronics/physics (the maths was a bit above me at the time). It may appear I've taken a scattergun approach to this and others but I'd like to think I have been a bit more focussed than that.
Anyway, the calibration.
Are we talking about the same thing here? On this 'scope on the bottom left of the panel is a small copper protuberance on which one hangs the end of the x10 probe. Pressing the 'cal' button is meant to produce several traces on the screen and one uses a trimmer tool on the probe body to get the traces as they should be (the manual is very good here). Only the focus and intensity controls work at this setting; nothing else does.
I do NOT get ANY traces on the screen. Testing the output on the copper protuberance is meant to show 0.2V; it shows half this, hence my diving into the set to alter the trim pot hoping to see if an increase in voltage produced a trace; it didn't. The circuit for this in-built sig gen seems relatively simple and as there is a cheap-as-chips IC there, that was going to be my first call in the investigation. Unfortunately I'm on holiday for 3+ weeks and did not take the 'scope with me (my wife baulked at the inclusion of a Brompton...she's have gone ballistic if I'd have packed a 'scope as well!).
Obviously I'll investigate further on my return.
I am NOT using the internal trim pots to alter the X/Y settings.
BTW. I've just won an auction for several dilapidated radios which I'm going to use as guinea pigs.
Thanks again,
Richard.
