Tech model T-O3 Oscilloscope Controls

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sonolink

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Feb 15, 2010
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Hello guys,
I was given one of these as a gift. It's from the 60s and seems to work fine but I'm not familiar with some of the controls and would love to use it. Maybe someone could be so kind as to shed some light and explain please?

-vertical x100, x10, x1 I guess is the vertical scale in volts and the red knob is for fine tuning?

-Sync/phase: I know what it means but how do you use that?

-Horizontal -Int, +Int, Line, Ext, Amp. What are these settings? Again red knob is for fine tuning?

-Sweep Range Vernier: ?

-Finally, there are several inputs at the bottom. Is this a 2 channels Scope? What does "direct" stand for?

-1v P-P: is this a calibration input for a 1v sinusoïdal wave?

-Int.Mod: ?

Thanks a lot for your help!
Cheers
Sono
 

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My best guesses (my oldest scopes are quite a bit newer, but some of the terms are still close enough to make sense).

-vertical x100, x10, x1

May be in volts, or may just indicate gain of the vertical amp, so 10x or 100x amplification of the input signal, or just a unity buffer. Best way to check would be to input a known voltage (maybe just a battery would be convenient) on the x1 scale and check.
Calibrated to volts would make sense, though.

Sync/phase

If using an external trigger signal allows you to shift the display of the input signal relative to the external trigger.

Horizontal -Int, +Int, Line, Ext, Amp.

Indicates where the trigger for the horizontal trigger is sourced. Internal would be from the internal trigger circuit which triggers from the input signal, inversion of the trigger (you will have to play with that and see if it means trigger on falling slope instead of rising slope, or means trigger on voltage below zero instead of above zero).
Line means trigger from the power line (useful for power supply work or old televisions which where the broadcast signals were synchronized to power line frequency).
Ext is for external trigger signal applied to the horizontal input connector.
Not sure what "Amp" would indicate. Yes, red knob should be for fine tuning.

Sweep Range Vernier:

The sweep range is marked in kc/s, so likely means the horizontal range which will fit a cycle of that frequency on the screen. The "Vernier" word is printed in red, so likely means that the red knob is for fine adjustment of the horizontal range, since the main adjustment knob is very coarse.

Is this a 2 channels Scope? What does "direct" stand for?

No, it is a single channel scope with an input for the external trigger, or for a signal to drive the horizontal sweep so you can use X-Y mode.
Direct would likely indicate that it bypasses the input buffer amplifiers, so you would need a signal which can drive the input impedance of those inputs, and is already scaled appropriately.

1v P-P: is this a calibration input

It is likely a calibration output, you connect the input there and verify that the scope is working properly. "Modern" scopes (meaning late 1970's or newer) usually have a square wave output there so you can trim an adjustable capacitor on the probes to give best square wave response, which should be flattest frequency response.

-Int.Mod:

Presumably refers to modulation, but no scope I have used has that feature, so I am not sure whether it would be input or output. Likely has some use when working on radios.
 
It does not have to be the manual for that scope, most scopes have similar controls.
Here is one.
https://www.kevinchant.com/uploads/7/1/0/8/7108231/gould.__os3000._service_and_operating..pdfTry and think outside the box.
The OP doesn't know how to drive a simple scope, and you throw him a manual for a Ferrari, probably not helpful. Possibly something like oscilloscope-conar-250-s might be more like what the OP has. That web page has a PDF manual with a usage section that should prove educational.
 
Thanks a bunch for all your replies and links guys. I've got plenty to read now and I'm looking forward to using that scope!

Thanks again!
Cheers
Sono
 
The complete 16 page manual for that scope is at Radiomuseum. You can download only 3 pages per day. It's a real PITA, but at least it's possible to get it.
https://www.radiomuseum.org/r/tech_oscilloscope_to_3to.htmlThis scope does not have triggered sweep, is AC coupled only, 1.5 MHz bandwidth. I would be looking for something better.
Thanks a lot for the reply dmeek. I didn't notice the manual on that page, only the schematic!

Cheers
Sono
 
When you get to the schematic use the arrows to switch to the other pages. You can download 3 pages per day and 10 pages per week so it will take 9 days to get it all. Clicking on the image takes you to a page where you enter a name and your email, you will receive a link to download that page. Repeat another 15 times.
 

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