1960s power cable

Cornwal60s · Oct 4, 2020

Hi, newbie here looking for some help. I've recently picked up a late 60s record player and it came without a plug.

I'm based in the UK and the power cables are not coloured so unsure which is live and neutral!

One cable has a thin black and white striped thread within the sheathing, obviously identifying something, but I dont know which! Being an electrical novice I dont want to wire the plug incorrectly.... anybody come across this before and can help?

James · Oct 4, 2020

Is there a label on the player that says what voltage it runs at?
Also, are you certain that the wire pictured is a power cable, not a speaker cable?

Strima · Oct 4, 2020

That looks more like bellwire than a supply cable, can you post a picture up of the player and any manufacturers plate etc?

And if that is the original cable I would be looking at replacing it as a matter of course, at 60 years old the insulation might well be starting to breakdown.

Cornwal60s · Oct 4, 2020

Thanks both. It's a Lenco LG75 running at 220v, with cables running into power supply RCA cables are separate.

Agree that its definitely due a rewire, which is something I'm planning as part of the restoration, but keen to power on and check everything is running before progressing any further!

telectrix · Oct 4, 2020

a clearer pic of that label showing all lettering would help.

Strima · Oct 4, 2020

What does the bit circled in red say?

Cornwal60s · Oct 4, 2020

Does this help at all? The cable marked in red are the outputs

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The bit circuled in red says 220v Switch Over Diagram

Strima · Oct 4, 2020

As that's dual voltage I suspect its an American make? Looks like the live needs to go to the second port from the right that connects to the large red jumper cable.

stewartrossinv · Oct 4, 2020

The Goldring-Lenco GL75 is a vintage turntable dating back to the late 60s/early 70s. It could be supplied as a chassis for building into a bespoke stereo system, or fitted into a case and supplied complete with arm as a stand-alone turntable.

The mains input wiring you show is not original, as commercial examples would have followed the red/black convention of the day and had a separate outer PVC sheath. I suspect the cable you show in your photo is really for loudspeaker use, as many such cables are figure of eight in cross section with a thin black stripe on one of the PVC insulators simply used to ensure that they can be wired like with like (+ to + and - to -) for stereo pairs.

You will certainly need to rewire using 3-core flex, with the green-yellow cable connected to the metal chassis of the turntable to ensure that a proper earth path is provided. When you connect the two signal cables from the arm to an amplifier you will be providing a path to earth through the screen of the signal cable via the amplifier, so the last thing you want is to get a shock while attaching the cables to the amplifier or for the turntable to go bang and trip your mains mcb or fuse through poor wiring.

-Stewart

Cornwal60s · Oct 4, 2020

Thanks Stewart, that's really useful. As suggested I'll pick up some new flex and rewire, including earthing to the chassis.

Just to confirm, as suggested just to double check, Live would be the 2nd from right where the red jumper cable is

stewartrossinv · Oct 4, 2020

Can't be certain, but it seems to be the most likely. It follows the red-black convention, with the right-most being the neutral in black (I assume).

I guess the other figure of eight connection shown (connected to the leftmost terminal and the assumed neutral on the right) goes to an on-off switch somewhere?

Cornwal60s · Oct 4, 2020

Hopefully this is a bit clearer, and you can see yes, it does to the feed to the on/off switch on right hand side

stewartrossinv · Oct 4, 2020

I think that reverses how you should treat the live and neutral. The switch cable is connected in common with the incoming power cable on the right side, so this has to be the live feed as otherwise the switch would be breaking the neutral, which wouldn't make sense and would leave the motor circuit connected live with no neutral when you switch off - clearly dangerous. Can only suggest you try wiring live to the right given the way the switch is wired, and bear in mind the dangers of getting it wrong.

Whoever wired the connections may have moved some of the jumpers to get it all going, so the red/black convention may well have been thrown out the window...

Use a multimeter to test as you go I would suggest.

-S
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Found a post in a specialist forum. Reading the post linked, the right-most IS the live. See The Lenco Motor - Lenco Glossary - Lenco Heaven Turntable Forum - https://www.lencoheaven.net/forum/index.php?topic=68.0

Cornwal60s · Oct 4, 2020

Really helpful Stewart thank you. It looks like you are correct in terms in reversing the live and neutral, going by this picture

littlespark · Oct 4, 2020

Looks incredibly clean for a record player of that age. The black plastic ones from 80’s and 90’s were always full of dust.

Cornwal60s · Oct 4, 2020

Not too bad at all. A couple of resident moths, but that's fairly standard for machines of this age!

Avo Mk8 · Oct 4, 2020

As a child playing with electrics from the '50's, who inherited a Lenco L75 turntable from dad, I can vouch that those white wires in the first posting are the original mains cable (if you Google you will see others like that).
Back then nobody much cared which was L or N!
It would probably be on a 5A round 2-pin plug anyway.
There was no earth other than through the audio cable.
I'm not saying it shouldn't be rewired, but suggestions it's replacement cable etc are not right. It's just how things were!

stewartrossinv · Oct 4, 2020

Good to know that the cable is indeed original and simply what was used. Back in 1976 I installed a stereo system made by Dynatron in a customer's home. It had a GL75 turntable in part of the system's very ornate wooden case, but I never saw the original wiring.

There's a thread on the Lenco forum about providing proper earthing for the chassis, available at Earth Wiring - Lenco Guides - Lenco Heaven Turntable Forum - https://www.lencoheaven.net/forum/index.php?topic=71.0

static zap · Oct 4, 2020

Clocks wires in clear "Bell wire "like material.
(plenty of cable did come from Woolies thought )

pc1966 · Oct 5, 2020

Yes, I remember Woolworths in the 70s/80s had a great selection of cable by the meter/yard, and various bits to go with it. Alas, they dropped all the car/DIY and eventually went completely. Along with the pick'n'mix sweets.

Cornwal60s · Oct 5, 2020

Yes, good to know it is the original cable so before rewiring later this week I can give it a quick power up now I know which cable is which. Certainly don't fancy using it properly with those cables though!

lozarus · Oct 6, 2020

As above don't even bother with that flex - just replace it, you may not even need to buy any flex as you'll likely have a suitable power cord around the house you can repurpse.

As an aside, having dealt with vintage record players a lot in my time, that mains flex may well be original. They didn't always use the standard red/black/green - see here for a brief bit on fig8 cable. It was often found on very low current appliances such as electric clocks and turntables. It was a bad idea all around as the insulation can get damaged just by looking at it.

Top tip if it's any use to you - I would say that 90 percent of decks I recieved as "no signs of life" were simply down to dried grease around the spindle - it really doesn't take a lot to stop the platter moving. This can be remedied by heating the grease up and thus extracting the spindle for cleaning and re-greasing

pc1966 · Oct 6, 2020

I think that type of original cable now would fail the regulations - it has exposed primary insulation.

As @lozarus says just replace it with something new. Also those decks are metal and should be earthed, that was not always done then either! So 3 core cable is needed, with a 3A fuse.
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You may need to put a ring terminal under some suitable screw for earthing if there is no dedicated terminal (as I suspect).

DPG · Oct 6, 2020

One thing to watch is earth loops. Turntables are very susceptible to this because of the very low (circa 3mV from a moving magnet cartridge) levels involved.

Often if you earth the deck you will get a hum loop because of the earth to the amplifier. If this happens you may have to remove the deck earth and connect a separate earth lead to the amplifier. All decent amplifiers that have a phono input have an earth terminal specifically for this purpose.

pc1966 · Oct 6, 2020

The other way to reduce "hum loops" is to use screened twisted pair cable so the screen is earthed at both the deck and the phono plug, but the "ground" pin of the cartridge is connected via one of the twisted pair and earthed only at the phono end.
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The basic idea:

For stereo you need 2 twisted pairs of course!

I have never been very happy about removing protective earths for noise reduction...

DPG · Oct 6, 2020

The above is a food good solution. In theory should work fine, but turntable/amp/cartridge combinations can be very unpredictable!
Definitely preferable if it does work though.

pc1966 · Oct 6, 2020

Having both deck & amp plugged in to the same outlet is a big help, and a length of heavy earthing cable between the two (as mentioned by @DPG before) can also help. But try it first and see how much you need to do to get it acceptably quiet.

If you have a modern amplifier that is double-insulated (i.e. not earthed itself) then you should have no problems!

Avo Mk8 · Oct 6, 2020

I was a bit out in my earlier post - I have been reminded that the original wiring had a separate yellow wire to chassis, that ran out with the mains lead, that you were expected to attach to the amplifier earth. Lenco thoughtfully also provided a tag strip under the lift-off platter, where the PU arm wires are terminated, isolated from the chassis (and with a chassis earth tag there with the yel. wire on it), so you could play with the cable screening arrangements if you needed.
Upgrading the unit to current earthing arrangements might undo some of the original flexibility, but I guess must be safer!