I recently was given this old oscilloscope, it was made by a friends late father in the late 60’s. I’m interested to know how to input a signal as I’m used to modern scopes with a bnc input.
I’ve drawn a schematic (attached) to try assist. It has 6 inputs, VERT, V.P, HORIZ and T.B plus 2 ground inputs.
The HORIZ and T.B were jumpered together when I was given it.

 

Vert is the input. T.B is the sweep (time base) output, which is connected to horizontal input for normal operation. You would remove the jumper for XY input.

Bob

 

That's by far the smallest sized CRT oscilloscope I've ever seen.

 

Vert is the input. T.B is the sweep (time base) output, which is connected to horizontal input for normal operation. You would remove the jumper for XY input.

Bob

Thanks Bob, any idea how the V.P input is used? I’m assuming it means vertical position.
Also, sorry for newbie question but if the T.B is normally connected to the horizontal input, what other uses would it have.
I’m interested in restoring this scope, I do understand that it would only be useful for quantative measurements, but I restore valve radios and would be interested to see it in operation when aligning the IF.

 

I agree that ir means vertical position. If you get to the point whete you are testing this, you might need a pot that set this to some range of voltages from negative through positive. No idea what range.

Bob

 

I built an oscilloscope in the early 60s using a 1" CRT like that one. I made it much smaller than that one using miniature hearing aid vacuum tubes. The final anode voltage on the CRT will be around +1,000VDC. Does that one use transistors or tubes? The input will probably be AC coupled and the amplifiers and timebase fairly low frequency. Give it a try with an audio frequency vertical input signal.

 

Many years ago I used my oscilloscope to show the "tangle of thread" image produced when its V input was one stereo music channel and the H input was the other stereo channel. The screen might get burnt if the dot is left not moving so it must be turned off when there are no input signals.

 

Thanks Bob, any idea how the V.P input is used? I’m assuming it means vertical position.
Also, sorry for newbie question but if the T.B is normally connected to the horizontal input, what other uses would it have.
I’m interested in restoring this scope, I do understand that it would only be useful for quantative measurements, but I restore valve radios and would be interested to see it in operation when aligning the IF.

You are correct. VP will be vertical position. If it is a similar CRT to the one I used, it will have electrostatic rather than electromagnetic deflection. The VP is acheived by applying a variable DC voltage to the output of the vertical differential amplifier.

 

With enough finangling you can make it work as an oscilloscope. Its a very basic circuit lacking any vertical calibration . Needs an external timebase and it will only accept AC signals. As an academic exercise, go for it - as a practical first oscilloscope its not what i would recommend.