STC830 I can assure you the output transformer is very healthy as the speaker gave a very loud hum. It seems to be built like a tank.

What do you guys think if me putting a Australian plug on this one ?

A bit of a difficult question Carl.
If it were mine, I would consider a rewire of the power supply using a normal isolated transformer.
Or restore as is, and run with an external isolation 1:1 transformer.
JJ

It's difficult to say. If it was me, for my own personal use, I'd put an Aussie plug on, and no earth wire. You'd have to make absolutely sure that nobody could touch any of the metalwork on the radio. I'd also add a note on the back, as a reminder of the inherit dangers of the design.

The schematic indicates that the antenna is isolated from the radio by a capacitor. Make sure it is fully mains-rated. Same with the earth connection (although I wouldn't use it because it might trip a leakage breaker).

There's no indication of an auxilliary input, so you should be otherwise safe as long as you are sensible about it.

I'm sure others will have opposing views - let's see what they say.

There are two different Oz Plugs. The big 1:1 240V Isolation transformer I have came with a plug Brad will know about, apparently lighting, which has a circular earth pin. That would stop the radio being plugged into anything other than the isolation transformer.

Funny how we used to accept dangerous things as normal. Think about toasters!
There was 240 volts, red hot and finger accessable right in your face.
You had to be careful and use a knife to get the bread crumbs out of the elements!!!
Crikey.
So now we have bucket loads of death trap radios about to appear on the secondary market on gumtree and ebay?
Should not the importers have some legal liability here?
I can see how our informed vintage radio people can handle the situation all being aware of the danger but how about when they get sold on. There will always be some sellers looking for a buck who hide behind ignorance and just change the plug to power up.

Those things have only 3 options, 1/ incinerate and landfill, 2/ power only with a separate isolation tranny and ground the metal work, 3/ rewind or replace the power tranny with an isolated primary and ground the metal work. I prefer option 3.

Am I being too harsh?
Fred.

a circular earth pin

Are they still in use? Haven't noticed those for a long time. I used to see them on sandwich toasters and the like in hot food shops with the associated GPO labelled "Process Heat".

Not same as a toaster. The socket is exactly the same as a standard mains socket, but for the round earth pin. Possibly discontinued? However, the object is to use a plug & socket that cannot be plugged into the standard one.

The panel socket I have (No Plug) is marked HPM CAT38 4905

Also be very careful of those Chinaman Hats (shield) on to of the Philips valves. those have a Bakelite strip in them which is easily crushed and that normally ends with a short.

I have actually had to repair several.

Not same as a toaster

If you reread what I wrote you'll see that I'm not referring to the kitchen toaster at home.

I know what they look like: http://updates.clipsal.com/assets/images/products/A0002438.PNG

I've only read the tail end of this discussion, so far...

Sockets with round earth pins are for lighting or other special purpose applications. One thing I always advise against is using any type of mains plugs or sockets for anything except conveying mains power. I've removed mains plugs and sockets from radios over the years for everything from supplying 4 volts to the vibrator version of a 500 series Radiolette and for audio connections.

Such applications are fine unless a radio is moved on or simply used by someone else thinking that the device is mains powered and I reckon we all know the scenario that follows. A loud bang followed by smoke and/or cardiac arrests.

Sockets with round earth pins are for lighting

Is that still the case anywhere? All the new buildings that I've seen in the last 10 years or so have the standard plug base sockets installed above the ceiling.

In the process heating case that I mentioned, I was told such circuits were on a different tariff, but I refer to decades ago.

"Am I being too harsh?"

Don't think you are. This set could be left unmodified for Australia only if it stays on your work bench under your supervision. Too much risk otherwise. It would only take a cracked or broken bakelite knob or a kid with a knitting needle for it to be a death trap to the uninitiated.

Maybe a fourth option would be cut off the plug and put it on the shelf to admire. Or to wonder at if put on the shelf back side out, without the back.

Is that still the case anywhere?

Yes but it's rare. When things like table lamps and portable feature lighting is controlled from light switches the sockets and plugs have to have round earth pins. Otherwise you could plug a 2400W heater into a lighting circuit and knock the circuit breaker out.

Different rules apply to ceiling spaces, where surface sockets for IXL lights and the older exhaust fans are commonplace. It is generally accepted that the average joe doesn't realise these sockets are in place and people are not likely to use them for silly purposes.

The autotransformer itself is physically separated from the main chassis. In fact it is mounted on wood. I will run a multimeter over it and see if one pin connects to the chassis.

My plan is to get this one going and then screw the back on. It really would be difficult to get a buzz out of this one the way it is built.