Bush DAC90A 2-Pin Mains Plug

[David G4EBT]

I've just acquired a DAC90A, and as is often the case, it came minus the 2-pin mains plug (or perhaps more correctly, 3-pin socket?) which fits onto ther protruding pins on the rear of the chassis.

I think that for safety reasons, some restorers prefer to dispense with this highly dubious mains connection arrangement, and instead, hard-wire the mains lead straight onto the switch on the volume control.

However, I usually allow nostalgia to over-ride common sense, and I'd prefer to leave things original and to retain the plug and socket arrangment, so I wondered if these plug jobbies are obtainable these days from any source, or are they like trying to find hens' teeth?

It makes me wonder how Bush got away with this malarkey, even back in the late 1940s!

At least the male pins are on the chassis - not sticking out of the the mains lead!

Regards,

David.
G4EBT

[plumbweiss]

They appear on ebay from time to time though they're not cheap. Probably a car boot bargain! I wouldn't be too worried about using one, okay the pins arent sleeved and the cable restraint on the earlier ones leaves alot to be desired but since most of them would be plugged into a lamp socket or 2A/3A outlet then thats not surprising. Im sure you're not going to put it in a baby's bedroom...

[Darren-UK]

Hi David,

These and many other AC/DC radios used what was then a standard 2pin, 5amp connector. As you no doubt know, Bush used their own design which was a chunky 'T' shaped effort with the Bush logo moulded into it. These do turn up on places such as ebay from time to time. Otherwise the ordinary mass-produced connectors are common secondhand. So far as I'm aware production of these ceased donkeys years ago. I have some of these laying around if you want one.

It wasn't so much a question of Bush 'getting away with it'; it was just the way it was all those years ago. AC/DC radios were produced for a number of reasons and, being 'live chassis' cannot be earthed - hence the 2pin connector sufficed.

Earthing an AC/DC radio is a topic that's arisen a few times on here; more specifically, earthing of the speaker grille. You may care to read this thread on this very subject.

Choosing my words carefully, such radios are as safe as they can be given sensible precautions and ensuring the chassis is connected to the neutral side of the mains.

I think you'll find most collectors use these radios as originally designed. I have heard of cases wherein people dispense with the connector and 'hard wire' the radio, but this really isn't necessary in my view. Likely, most instances of this are simply down to the fact that the connector has gone missing.

To everyone, please remember this is the 'Components and Circuits' section, any further comments on earthing and/or safety can be added to the other thread linked above....which may be edited and archived in due course.

[Phil G4SPZ]

Originally Posted by G4EBT

I wondered if these plug jobbies are obtainable these days from any source, or are they like trying to find hens' teeth?

David G4EBT

David,

Yes, they are like hen's teeth, because the people who have them in their stock know what they are used for! A similar non-polarised 5 amp 2-pin cable-mounted socket is needed for the mains inlet to the PCR receiver and other more recent things such as the Quad II amplifier and pre-amp. I have both, and have managed to make up suitable connectors by starting with a 5-amp 2-pin plug like the one shown, which ARE more readily available and have the same two-part body shell. You will find that the brass socket tubes within modern readily-available 3-pin cable connectors, such as those sold for the mains cables on lawnmowers and the like, are the same diameter to make a good fit on the pins, and will fit into the body shell of the 2-pin plug with a bit of ingenuity.

I have made up two sockets in this way; one went together without modification, and on the other I had to grind away a tiny portion of the plastic housing with a Dremel tool, merely because the cable securing screws in the socket tubes had bigger heads.

Although it would not be granted a CE mark, I believe this is a safe method of operating vintage radios for personal use.

Phil

[M0TAW Tony]

David
They're around - at a price. I saw a Bush one go for £14.00 plus P&P by auction!! I needed one (well I thought I did) and had to pay a fiver at the Shifnal meet a couple of weeks ago. Silly money when you could have picked up a reasonable valve set complete for £2.00 at the same venue.
Tony

[Sean Williams]

I might be persuaded to part with one of my 2 pole 5a bulgin connectors if asked.....

[Phil G4SPZ]

Originally Posted by M0TAW Tony

...had to pay a fiver at the Shifnal meet a couple of weeks ago. Silly money when you could have picked up a reasonable valve set complete for £2.00 at the same venue.

Yes, it's a shame and (in my experience) very unusual in vintage radio circles to find people attempting to profiteer like that, but I suppose it's the law of supply and demand when sought-after components become rare. Nevertheless, necessity is the mother of invention, but avoiding being ripped off is an even greater spur to ingenuity, so now I make my own connectors as described. Who was it who famously said something like "an engineer can do for one shilling what any fool can do for a pound"?

Phil

[David G4EBT]

Thanks for all the helpful comments guys, and for the interesting link by Darren to the thread on the merits or otherwise of earthing the speaker grille. What a hot topic ('scuse the pun!) that became!

I've always had a soft spot for the DAC90A - we had one when I was a child, so there's always a touch of nostalgia - it evokes memories of Dan Dare, the Eagle comic, sweets coming off ration, first pair of long trousers, first two-wheeler bike... etc

So when at car boot sales or rallies, I see a DAC90a at a sensible price (always bearing in mind the liklihood of a costly new output valve being needed) I can't resist the temptation to buy.

I acquired this latest one from a car boot sale - the guy wanted £30 for it at 8am, but he'd had no takers by 12 noon so I offered him £20 and pointed out the lack of the plug, and he grudgingly accepted.

The cabinet's come up nice with some bakelite polish, the speaker fret and dial is unmarked, but the electrics need some attention to get it up and running again.

Anyway guys, thanks once more for your interesting and helpful comments.

I think that on balance, I'm going to remove the two mains pins, and hard wire a mains lead via a grommet in the paxolin disc. Safer, less hassle, and I don't think it will detract in quite the same way as many mods might do.

Regards to all,

David,
G4EBT.

[Nickthedentist]

Originally Posted by G4EBT

I think that on balance, I'm going to remove the two mains pins, and hard wire a mains lead via a grommet in the paxolin disc.

I've done this to a couple of sets, but now wish I hadn't. It never looks right, and it's difficult to cut a really neat 1/2" hole centrally in the Paxolin to accept a modern strain relief grommet. And the two little holes either side of it look messy too.

If you do feel the need to fit a captive mains lead, how about drilling out the rivets that hold the Paxolin panel in place, and making a replacement to fit? A piece of ABS cut from an old project box (or the cabinet of a scrap TV) would do nicely. The original panel could then be stored safely away, and reinstared if someone wanted to "go original" one day in the future.

P.S. Do the Duraplug lawnmower-type connectors fit (possibly with the shroud cut off with a craft knife)? These are readily available (just) for a couple of quid at most.

Nick.

[Tim]

I've done this to a couple of sets, but now wish I hadn't. It never looks right, and it's difficult to cut a really neat 1/2" hole centrally in the Paxolin to accept a modern strain relief grommet. And the two little holes either side of it look messy too.

I simply enlarge the central slot(between the two holes left when the pins are removed) out to about 6-8mm and fit an ordinary grommet(the flanges of which conceal any mess). A P clip secured to a handy bolt takes care of strain relief requirements. When I do the next one I'll post a picture.

Would the paxolin panel be strong enough for anchoring a strain releif? I don't know if I would trust it.

[Nickthedentist]

Thanks Tim.

Originally Posted by Tim

Would the paxolin panel be strong enough for anchoring a strain releif? I don't know if I would trust it.

Yes, it's fine in that respect, but again, it those black plastic SR bushes don't really look right on a pre-1970s set.

Nick.