Grundig TK23

[croz1950]

Have just retrieved my original 1960s TK23 from the loft. I have "lost" the power cord somewhere in the last 40 years .... and it seems to be nothing like any of the modern equivalents, judging by the socket (picture below ...this is a UK made model so it doesn't have the power cord traliing out from the small door aperture which is how the European models were, I think, set up).

I was intending to hot wire it, just to see if it powers up. Am I right in thinking I can just connect live and neutral feeds to the red and black wires, pictured ? Assume the third red wire is an earth connection ?

Thanks for any expert advice available.

[Sideband]

That looks like a standard Bulgin connector. Plenty available on eBay.

[croz1950]

Thanks....I was just about to update with a question about Bulgin having looked at an old post on this forum ....I guess I need one of these...safer than hotwiring !

[TonyDuell]

That does indeed look like the normal (small) Bulgin mains connector. Years ago it was rated at 1.5A, now it seems to be 3A (I am not sure what changed!). You can get the cable-mounting socket to mate with it quite easily. The straight one is PX0646, the right-angle one is PX0430/SE. RS do both, but are out of stock at the moment.

Those connectors are assembled with screws. At one time there was one with a screw-on cap that could be removed without a tool, exposing live terminals. That one was later only suitable for use below 50V unless inaccessible without the use of a tool. I notice that the ones I have just mentioned now carry that restriction, I am not sure why, but I wouldn't worry about it for my own use. AFAIK there is no way to expose live parts on them unless you undo screws.

The conventional way that these connectors are wired is that the 2 pins near the locating groove are the current-carrying pins (live and neutral), the longer pin opposite the locator is earth. For this tape recorder I doubt it matters which way live and neutral are connected although I would follow the wiring inside the unit and make the red wire live and the black neutral. The other wire, to the chassis, must be earth.

[Lucien Nunes]

I was intending to hot wire it, just to see if it powers up

This may not be a good strategy if it has been unused for a long time. If the main HT electrolytics are bad, which they often are through disuse, applying power can damage the rectifier and possibly the transformer. I think this model may have an HT fuse but I am not sure whether its position in the circuit offers good protection from shorted electrolytics. I would suggest powering via a lamp limiter first, or testing / reforming the electrolytics. Not long ago I accidentally powered up a TK18 that had been on the shelf for years (I thought it was a different one) and smoked the rectifier instantly.