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Bought my first oscilloscope

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I've finished the display unit today. The final steps were to readjust the PSU voltage rails tweaking the focus, brightness and geometry and cleaning the frontpanel and the knobs.

Here's what the panels looked like before a bath in hot soapy water.

The right tongue angle is important when tweaking trimmers.

I also had to replace some knobs, thankfully even 40 years after this scope was built there are still very similar knobs available and I have a good assortment of them to hand.

The V/div vernier knob for channel one was a bit of a challenge as the original was broken and needed to be replaced. Of course it is one of those stacked knobs that are notoriously hard to get. With some luck you can make them yourself.
The problem here was the potentiometer shaft the knob sits on is very thin, only 2,5mm. No standard knob will fit this.
The knobs used on this scope have a brass insert and a collet that clamps down on the shaft. The knobs I had available work the same way but with standard 4 or 6mm collets. So I had to transplant the collet of the broken knob into the new one.

Heat is your friend for this kind of job. I just stuck the iron into the old knob and pushed the brass insert out. Then did the same with the new knob. The diameter of the insert in the new knob is a bit bigger so I glued the brass part from the old knob into the knob with a bit of epoxy. Let it set and it's ready for assembly.

Doesn't look too bad. Here's the cleaned and repaired Y Amplifier

It's a pity the clear indicator discs around the time/div and V/div knobs are yellowed. I don't know if I can replace them with new ones as those are usually knob specific. I'll probably leave it like that.

While working on the deflection unit I noticed more parts of the manual are missing, which is a problem for me as I wanted to realign the scope properly. I will have to contact Siemens if they have a complete copy of the manual.

Very interesting model. Love the green display. I'm still using a 20 year-old Hitachi analog here so I can tell you they still are very useful!  ;)

Yes, I know. This isn't my first scope - just the first I actually paid money for  8). I have a Hitachi, too.

You'll learn a lt of things repairing scopes that nobody want... I 've done the same...


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