Heathkit stabilised power supply MSP-1

[deco-doctor]

Hi all - I have a rather nice Heathkit Daystrom stabilised HT bench power supply, model MSP-1. I have been looking on the net for a circuit diagram for it, but to no avail.

It has an adjustable HT supply from 200 to 400V @250mA in three ranges, it uses a GZ37 rectifier and two ECC83's (presumably as voltage/error amplifier), a GD83M voltage reference valve and a large 6080 double triode as the pass valve. I have a supply of all the valves as spares except for the GD83M reference valve which seems to be unobtanium.

I have some 5651WA voltage reference valves which seem to be a near equivalent, but run at a lower current than the GD83M. Hence the need to find a schematic so I can figure out how to use the 5651 in place of the GD83M.

Can anyone here help with a source of a circuit diagram please?

Many thanks

Martin

G4IYA

[ronbryan]

Martin

I've found a hard copy Heathkit MSP-1M schematic in my test equipment file. The reference tube on that unit is an 83A1, but the rest of the valves are as you describe.

The 83A1 is fed from resistors connected to the paralled 6080 cathodes. These are selected by one pole of the range switch. The low voltage range uses 27k, the 250-325V range uses 43k and the high voltage range uses 56k. Unsurprisingly the reference voltage is shown as 83V.

Ron

[deco-doctor]

Originally Posted by ronbryan

The 83A1 is fed from resistors connected to the paralled 6080 cathodes. These are selected by one pole of the range switch. The low voltage range uses 27k, the 250-325V range uses 43k and the high voltage range uses 56k. Unsurprisingly the reference voltage is shown as 83V.

Ron

Hi Ron

Thank you, thats exactly what I needed to know

Is there any possibility of scan of the circuit diagram? I have looked all over the net and I cannot find any reference this model power supply anywhere.

Martin

[igranic]

The MSP-1M seems to have only been supplied by the Gloucester, UK, factory. There were two versions: the MSP-1M with meters, and the MSP-1W without meters. As far as I am aware, it did not appear in the Heathkit USA catalogues.



HTH

Edward

[deco-doctor]

Originally Posted by igranic

The MSP-1M seems to have only been supplied by the Gloucester, UK, factory. There were two versions: the MSP-1M with meters, and the MSP-1W without meters. As far as I am aware, it did not appear in the Heathkit USA catalogues.

Hi Edward

That may explain why I was having difficulty finding the circuit. I am very grateful to you for posting the circuit. My thanks to all who responded.

Martin