Had to concede defeat with my efforts to find the fault in this cathode-ray-oscillosope (CRO), or 'scope'. And that's despite being in the fortunate position of having the original manual, and circuit diagram (a very rare inclusion with equipment these days). I suppose that keeping it (and many others) working for the last twenty odd years is pretty good going, especially as the inexperienced "Users" are fairly harsh with them. As there's several thousand volts needed to produce that "cathode ray," I'm very wary of touching anything when "live working" is required... i.e. Don't try this at home!

A 'scope' is a fancy piece of electronic test equipment that's used to display voltages. You will have seen something very similar used in all those medical programs on the television - that screen showing the "blips" of someone's heart beat... or, for the less fortunate, "flat-lining." That's just a slight variation on the more sophisticated one shown above. Modern scopes are much smaller, and are at last reaching sensibly affordable prices. A handy piece of equipment for the Electronics Engineer to use to test other equipment, or to locate faults with. Well, assuming the thing itself is working!

The "cathode ray tube" is the large bit at the top. It has similarities in its working, to that of the older televisions, before plasma/LCD/LED types.