Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply - UK Vintage Radio Repair and Restoration Discussion Forum

Henenen · 8th May 2022, 2:04 pm

How would a novice go about finding/creating a 5-Pin power supply for a 1960s Telefunken Magnetophon 302 machine?

The unit states 6V, and the socket is pretty standard 5-Pin, like this: https://en.wikipedia.org/wiki/File

IN-5_Diagram.svg

I've found a circuit diagram, and on Page 2, 'e' shows the 5-pin 6V power, but I don't really understand what each of the numbered pins are?

https://archive.org/details/manual_3...ge/n1/mode/1up

Anyone made/adapted a PSU to use with one of these before?

ms660 · 8th May 2022, 2:55 pm

So far as I can make out for an external 6 Volt supply, pin 1 is +ve and pin 2 is -ve, any internal supply is disconnected when the din plug is plugged in which opens the contacts of S5 and S6.

Lawrence.

Uncle Bulgaria · 8th May 2022, 3:07 pm

If you can't find an old lead for the specific purpose, then you'll have to make one if you're set up for soldering.

DIN plugs and sockets of the type you posted are common - I have quite a few as I like using them. Then it's a case of study the circuit diagram to check inputs and outputs and solder up the required wires, with the other end of the cable wired into your preferred power source. What are you intending to use with it?

If it seems too much I can make up a cable for you.

Henenen · 8th May 2022, 4:58 pm

Ah, thank you for the offer. I'd like to try and solder one up myself. If something off-the-shelf already existed I'd go with that, but have been able to find anything likely so far.

So could I use anything from, for example, this page?
https://www.acadaptorsrus.co.uk/ac-adaptors/6v/

I see there's different mA offerings. Is there a way to find out what the Magnetophone would require?

So is it really just a case of snipping the connector off and soldering the positive wire to Pin 1 and the negative wire to Pin 2 (as ms660 figured out)?

ms660 · 8th May 2022, 5:12 pm

Quote:

Originally Posted by Henenen

Ah, thank you for the offer. I'd like to try and solder one up myself.

So could I use anything from, for example, this page?
https://www.acadaptorsrus.co.uk/ac-adaptors/6v/

I see there's different mA offerings. Is there a way to find out what the Magnetophone would require?

So is it really just a case of snipping the connector off and soldering the positive wire to Pin 1 and the negative wire to Pin 2 (as ms660 figured out)?

600mA in rewind according to a manual I'm looking at.

Yes just connect the output of the 6 Volt PSU to pin 1 (+ve) and pin 2 (-ve)

Pins 1 and 3&5 are for charging the re-chargeable battery if fitted.

Lawrence.

Henenen · 8th May 2022, 6:27 pm

Fantastic, thank you. I'll get scouring the car boots for an old 6V 600mA adapter.

If I find one that's more mA, eg 1000mA, that would be ok to use too?

And the 5-din plug, I can use any? (It doesn't have to be anything special to carry the 6V?)

Uncle Bulgaria · 8th May 2022, 6:41 pm

Yes, it doesn't matter. Current draw is determined by the component circuitry not the supply, so it won't draw more than specified unless there's a fault - that's what a fuse is for. If the current increases beyond the fuse rating, then it overheats and melts, breaking the circuit.

If using a 'wall wart' type adaptor, just cut the connector off the end of the cable, strip the ends and connect to the DIN connector observing the relevant polarity. Check the numbering of the pins. Sometimes it is not clear whether the diagram is drawn from the solder side or connector side and it is possible to wire back to front. Usually the plugs and sockets include moulded numbers next to each pin to preclude this eventuality. If not, the manufacturer's datasheet will say. I always forget which way is assumed to be standard, so have to check each time.

Using a short length of heatshrink tubing will help reinforce the DIN end, providing extra strain relief and a tidy joint.

Yes, any 5-pin 180 degree DIN will work. Some of the DINs look similar but have different pin spacing. In this case the manual and your Wikipedia link show a 180 degree not a 60 degree. I like to use Deltron plugs with a nice metal body - Farnell number 1193826.

DMcMahon · 8th May 2022, 8:28 pm

Haver you tried operating it on internal batteries to make sure it is functional ?

David

Henenen · 8th May 2022, 8:33 pm

Indeed I have David, and though it could probably do with a service (sound is a bit distorted at any volume over '2'), it seems to function OK.

Henenen · 28th May 2022, 2:58 pm

Hey everybody... so I've now found an old 6V 600mA power adapter and a 5 pin din plug.

I've snipped the original connector off and went to double check which wire was positive and negative with a multimeter, but in doing so noticed the voltage reading was actually 8.7v, rather than 6v. Is that usual?

Will the Telefunken machine be able to cope with the extra voltage, do you think?

Andrew2 · 28th May 2022, 3:13 pm

It will be an unregulated supply so it will drop under load, although you should check this.

Henenen · 28th May 2022, 5:56 pm

Would this involve opening it up and probing somewhere?

DMcMahon · 30th May 2022, 9:44 am

The 6V adapter being 8.7V off load does sound a bit high but as Andrew suggests probably is just a poor regulated PSU and will drop closer to 6V when loaded.

When the unit runs on its 5 internal batteries, battery supply voltage will be at least 7.5V (with good batteries).

I would just try the adapter connected to the unit and measure the supply voltage at the DIN connector pins (be careful not to short out the pins when measuring) with unit switched on.

I think there is some further voltage regulation in the 302 electronics.

David

8th May 2022, 2:04 pm	#1
Henenen Tetrode Join Date: Mar 2011 Location: London, UK. Posts: 81	Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply How would a novice go about finding/creating a 5-Pin power supply for a 1960s Telefunken Magnetophon 302 machine? The unit states 6V, and the socket is pretty standard 5-Pin, like this: https://en.wikipedia.org/wiki/FileIN-5_Diagram.svg I've found a circuit diagram, and on Page 2, 'e' shows the 5-pin 6V power, but I don't really understand what each of the numbered pins are? https://archive.org/details/manual_3...ge/n1/mode/1up Anyone made/adapted a PSU to use with one of these before?

8th May 2022, 2:55 pm	#2
ms660 Dekatron Join Date: Apr 2011 Location: Cornwall, UK. Posts: 13,454	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply So far as I can make out for an external 6 Volt supply, pin 1 is +ve and pin 2 is -ve, any internal supply is disconnected when the din plug is plugged in which opens the contacts of S5 and S6. Lawrence.

8th May 2022, 3:07 pm	#3
Uncle Bulgaria Nonode Join Date: May 2016 Location: Cornwall, UK. Posts: 2,333	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply If you can't find an old lead for the specific purpose, then you'll have to make one if you're set up for soldering. DIN plugs and sockets of the type you posted are common - I have quite a few as I like using them. Then it's a case of study the circuit diagram to check inputs and outputs and solder up the required wires, with the other end of the cable wired into your preferred power source. What are you intending to use with it? If it seems too much I can make up a cable for you.

8th May 2022, 4:58 pm	#4
Henenen Tetrode Join Date: Mar 2011 Location: London, UK. Posts: 81	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply Ah, thank you for the offer. I'd like to try and solder one up myself. If something off-the-shelf already existed I'd go with that, but have been able to find anything likely so far. So could I use anything from, for example, this page? https://www.acadaptorsrus.co.uk/ac-adaptors/6v/ I see there's different mA offerings. Is there a way to find out what the Magnetophone would require? So is it really just a case of snipping the connector off and soldering the positive wire to Pin 1 and the negative wire to Pin 2 (as ms660 figured out)? Last edited by Henenen; 8th May 2022 at 5:08 pm.

8th May 2022, 6:27 pm	#6
Henenen Tetrode Join Date: Mar 2011 Location: London, UK. Posts: 81	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply Fantastic, thank you. I'll get scouring the car boots for an old 6V 600mA adapter. If I find one that's more mA, eg 1000mA, that would be ok to use too? And the 5-din plug, I can use any? (It doesn't have to be anything special to carry the 6V?)

8th May 2022, 6:41 pm	#7
Uncle Bulgaria Nonode Join Date: May 2016 Location: Cornwall, UK. Posts: 2,333	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply Yes, it doesn't matter. Current draw is determined by the component circuitry not the supply, so it won't draw more than specified unless there's a fault - that's what a fuse is for. If the current increases beyond the fuse rating, then it overheats and melts, breaking the circuit. If using a 'wall wart' type adaptor, just cut the connector off the end of the cable, strip the ends and connect to the DIN connector observing the relevant polarity. Check the numbering of the pins. Sometimes it is not clear whether the diagram is drawn from the solder side or connector side and it is possible to wire back to front. Usually the plugs and sockets include moulded numbers next to each pin to preclude this eventuality. If not, the manufacturer's datasheet will say. I always forget which way is assumed to be standard, so have to check each time. Using a short length of heatshrink tubing will help reinforce the DIN end, providing extra strain relief and a tidy joint. Yes, any 5-pin 180 degree DIN will work. Some of the DINs look similar but have different pin spacing. In this case the manual and your Wikipedia link show a 180 degree not a 60 degree. I like to use Deltron plugs with a nice metal body - Farnell number 1193826.

8th May 2022, 8:28 pm	#8
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,600	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply Haver you tried operating it on internal batteries to make sure it is functional ? David

8th May 2022, 8:33 pm	#9
Henenen Tetrode Join Date: Mar 2011 Location: London, UK. Posts: 81	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply Indeed I have David, and though it could probably do with a service (sound is a bit distorted at any volume over '2'), it seems to function OK.

28th May 2022, 2:58 pm	#10
Henenen Tetrode Join Date: Mar 2011 Location: London, UK. Posts: 81	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply Hey everybody... so I've now found an old 6V 600mA power adapter and a 5 pin din plug. I've snipped the original connector off and went to double check which wire was positive and negative with a multimeter, but in doing so noticed the voltage reading was actually 8.7v, rather than 6v. Is that usual? Will the Telefunken machine be able to cope with the extra voltage, do you think?

28th May 2022, 3:13 pm	#11
Andrew2 Nonode Join Date: Mar 2010 Location: Dukinfield, Cheshire, UK. Posts: 2,037	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply It will be an unregulated supply so it will drop under load, although you should check this. __________________ Andy G1HBE.

28th May 2022, 5:56 pm	#12
Henenen Tetrode Join Date: Mar 2011 Location: London, UK. Posts: 81	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply Would this involve opening it up and probing somewhere?

30th May 2022, 9:44 am	#13
DMcMahon Dekatron Join Date: Apr 2019 Location: Worthing, West Sussex, UK. Posts: 6,600	Re: Telefunken Magnetophon 302 Reel to Reel 5-Pin Power Supply The 6V adapter being 8.7V off load does sound a bit high but as Andrew suggests probably is just a poor regulated PSU and will drop closer to 6V when loaded. When the unit runs on its 5 internal batteries, battery supply voltage will be at least 7.5V (with good batteries). I would just try the adapter connected to the unit and measure the supply voltage at the DIN connector pins (be careful not to short out the pins when measuring) with unit switched on. I think there is some further voltage regulation in the 302 electronics. David