Oscilloscope not used in years
 

Hi all, I am sat at work at the moment and it has occurred to me that I have a scope in the garage which I picked up from a boot sale around 15 years ago. The only reason I bought it was because it was a £1. I had no need for one at the time and no idea how to use it correctly. I did plug a Walkman into it to see if it worked and it did give a pattern. That was 15 years ago. The unit has been sat in an unheated garage all this time. From memory I would say it could have been built in the 60s but I'm not certain.

At some point in the next week or so I will retrieve the scope and see if it is still operational.

Is there anything I should check before powering up? I have no means of slowly bringing the working voltage up.

Once I dig it out I can give you more specs .

Cheers. Brett.

Re: Oscilloscope not used in years
 

I would give it a spell in the airing cupboard or another warm place for a month or two before doing anything.

Re: Oscilloscope not used in years
 

Ok. It will give me some time to read up on using said item. Would be great if it works .

If you could leave the thread open I will get some more details of the model and the members might be able to shed some light on its origins etc.

Many thanks.

Re: Oscilloscope not used in years
 

You will certainly need to reform the capacitors before giving it any real power at least.

Re: Oscilloscope not used in years
 

If you could tell us the make and model of the oscilloscope we might know of any particular things to watch out for.

Re: Oscilloscope not used in years
 

Build a lamp limiter and power it through that. Better than nowt.

Andy.

Re: Oscilloscope not used in years
 

Hi . It’s a tecalemit . I’m struggling to copy and paste the code on my iPad, but there is a photo in my album if you care to take a peek.

Cheers.

Re: Oscilloscope not used in years
 

Are you sure? As far as I am aware, Tecalemit make garage equipment. I suppose it could be some kind of engine analyser....
How do we access your photo album?
Colin.

Re: Oscilloscope not used in years
 

Hello,
It appears to be a Telequipment S51A from the picture.
Yours, Richard

Re: Oscilloscope not used in years
 

From Brettski's album:

Re: Oscilloscope not used in years
 

It is indeed a sixties Telequipment S51A Serviscope. Basic valve scope but well worth a pound. Have just restored one of these after years in storage and will post more info when I get a spare minute.

Alan

Re: Oscilloscope not used in years
 

Thanks AC/HL . Could well be vehicle related. I work in the motor trade and we sell Tecalimit ramps .

Ooo yes please. Any pointers you have would be greatly appreciated.

I’m guessing I will be able to learn how to use this and apply it to restoring Transistor radios .

Many thanks. Brett.

Re: Oscilloscope not used in years
 

Don’t those have those big selenium stick rectifiers? Not sure I’d be happy to fire one up without replacing it if it did.

Re: Oscilloscope not used in years
 

Yes those things do tend to get a bit whiffy when they are powered up after damp or being left unused for a few years.

Re: Oscilloscope not used in years
 

They do Mr B and often die when first powered up.

If it were mine Brett, open it up, check that all the valves are there and no valves gone to air, they will be white if they have, and have no getter silvering.

Next check that all resistors and caps look ok, post some good quality pics here, some members have eyes like hawks and can spot a dodgy component from 1000ft.

Give the valves a wiggle, check there are no dead spiders etc sitting across EHT components and GENTLY power up on a lamp limiter. A variac would be better, but you haven't got one.

These are good scopes to cut your teeth on, being pretty simple.

Andy.

Re: Oscilloscope not used in years
 

Thanks Andy, I’m going to leave it for a while to dry properly. But I will get it opened at some point.

Watch this space :thumbsup:

Re: Oscilloscope not used in years
 

Definitely go along with being patient with a long, month + stretch in a warm, dry place before even thinking about powering. If there was ever a common weak spot with just about every CRT 'scope ever made, it's the EHT supply wound components- whether mains- or HF-inverter derived, there are many, many turns of fine wire with lots of volts between them just looking for an excuse for a burn-up and long-term humidity and lack of use encourage insulation degradation. A good excuse to knock up a lamp-limiter in the time and use a 60W or thereabouts bulb to ensure a gentle-wake-up stint before it gets full mains,

Good luck with it, Colin.

Re: Oscilloscope not used in years
 

I have reconditioned dozens of the TQ valve scopes with the long selenium HV rectifiers. I have NEVER had a smelly failure. However I did find the output voltage reduced, presumably due to age and use. I made up a simple tester using a neon relaxation oscillator with which I just counted the flash rate. A bit slow and replace, but as said, never a failure.
I have repaired quite a few TV sets with selenium multipliers, and whilst very aware others have had smelly failures, again I was lucky and never had one.
Les.

Re: Oscilloscope not used in years
 

I dimly recall some equipment emitting these fumes being removed from the house at great speed by my father in about 1975. It is toxic and quite harsh on the lungs.

Re: Oscilloscope not used in years
 

Sorry for the delay Brett. Lots of good advice offered by others here. My S51A had been in a dry but unheated cellar for ten years when I decided to bring it out of mothballs. Originally came from a boot sale too.

I would take it out of its case now as that will help to air things out more quickly. Just undo the two screws at the back and the chassis will slide out forwards. Can take a bit of jiggling.

Google and download the manual. Study the user instructions carefully so you know what it should do when it comes to testing. There were several different versions of the S51 (A, B, E & T from memory). They're all similar in terms of use but the circuit diagrams vary so don't worry about those for the moment.

Do construct a lamp limiter as described on the main pages of this site and make sure you understand how to use it. Mine actually fired up without any problems once I'd sorted out the mains cable earth wire which had broken away at the solder joint. This fault was obvious (and dangerous) with the case removed. By the way, the mains lead on mine used the old red, black and green colour scheme.

I notice that your main interest is battery powered radios so don't even think of messing with the scope internally unless you are entirely confident about the safety measures needed when dealing with very high voltages. Often said here but worth repeating I think.

Best of luck and let us know how you get on.

Alan