SE Labs SM-111 Oscilloscope

[Yorkie]

This thread might interest you, which concerns the restoration of an SE Labs SM112, which has similarities to the SM111:

http://golbornevintageradio.org/forum/sh...p?tid=1168

If you don’t have the manual, you can download the SE Labs SM111 Oscilloscope Instructions covering both Operating Guide & Circuits Schematics Service Manual CDC-673 for £8.50 from here:

http://www.mauritron.com/selabs.html

As to your mains input socket, as Mark says, it’s most likely a Bulgin, but without the attachment, it's difficult to say. This is what the mains lead may look like:

Bulgin Mini-socket (female) for mains lead:

http://www.ecrater.co.uk/p/13931441/1-x-...-for?gps=1

This may look like what you have on your scope - chassis mounting mains socket (male):

http://www.ebay.co.uk/itm/Bulgin-3-pin-R...p3284.m263&_trkparms=algo%3DSIC%26its%3DI%26itu%3DUCI%252BIA%252BUA%252BFICS%252BUFI%26otn%3D21%26pmod%3D200838890649%26ps%3D54

The terms ‘plug’ and ‘socket’ aren’t really interchangeable, but are often treated as such. Strictly speaking, a plug has male connectors and a socket is a receptacle with female holes into which the male socket mates. For obvious reasons, you can’t have a ‘plug’ with male pins at the end of a mains lead to plug into equipment, so what you have on the back of the scope, which many will refer to as a ‘socket’, pedants would argue is really a plug as it has male connectors.

Bulgin connectors are no longer used as they’re not very safe – you only have to look are how exposed the female holes are to realise that they pose some risk of shock. Personally, if it was my scope and there is space to modify the mains input, I’d replace it with an IEC one. You can get IEC ones with a built in switch and fuse – for example, like this one:

http://compare.ebay.co.uk/like/271095728809?var=lv<yp=AllFixedPriceItemTypes&var=sbar&cbt=y

That type has the merit of ensuring that the correct fuse is fitted, whatever some idiot may decide to later fit in the 13A 3-pin mains plug.

Or plain ones, that like this:

http://www.ebay.co.uk/itm/Black-3-Pin-Te...p3284.m263&_trkparms=algo%3DSI%26its%3DI%26itu%3DUCI%252BRTU%252BUA%252BFICS%26otn%3D21%26pmod%3D160916262776%26ps%3D54

Or if you prefer to use a Bulgin one (no longer made), you’ll find one at a much higher price on e-bay or wherever.

Hope that helps a bit.

Best of luck with the scope!

Foornote re attachements:

Maybe you could have another attempt at attaching a pic Kevin?

To do that, when you've written your post, if you click on 'Preview'', then where it says 'New Attachment' at the bottom left, click on 'Browse' then find the attachement (for example in 'My Pictures'). then at the bottom right of the screen, click on 'add attachment'. After a few seconds, the attachement will be added. If you then preview your post again, if you've successfully attached your pic, you should see a little box with a red cross in it (not the actual picture). If you then click on 'Post Reply' the post will appear right away, with a thumbnail of the pic, which will enlarge when you click on it. You can attach several attachements one after another to your post before you upload it, by repeating the 'Add Attachment' routine for each pic.