I've often been surprised at how common live chassis designs are in overseas radios and TVs.

I wondered why we didn't see that much here.

Here is the main reason:

Manufacturers in Australia have always delegated warranty service to retailers, who often had large associated service divisions. Those that didn't would delegate warranty service to a contracting service company like the one I used to work for.

Service techs universally hated live chassis TVs in particular ("Death traps", "Widow makers") and would lobby the retailers not to sell them. Contracting service companies would put a premium on covering a live chassis TV, this was a further disincentive.

It didn't take long for manufacturers to get the message. AEI - Ekco was the best example. After trying to market a UK live chassis design they relented and the model that replaced it was a local design with a mains transformer. Ah, much better!

The few later TVs that were based on Euro or Japanese designs inevitably had transformers screwed into the bottom of the cabinets.

Service techs universally hated live chassis TVs in particular

With good reason. 240 volts is not to be toyed with.

Not many about Ian, I have only had about 2 hot chassis TVs pass through my hands and in the last year or so 50s TVs have dried up!!
I get lots of 60s hmv, pye, etc offered to me and I generally say no.
Unless its something unusual.
Pete

I've only ever owned one hot chassis radio, an AC/DC version of the Airzone Radiostar. Note that none of this model had a back on it so if the GPO or flex was not wired with the correct polarity one would not be holding the radio in their hands for very long.

When it comes to wiring of buildings, Australia's wiring rules were very strict but the same rules never carried over to the manufacture of appliances. If a company tried to release a beast like this today I doubt it'd make it off the production line.

In Western Australia AC/DC radio sets from the 30's & 40's are not uncommon. Outside the Perth area all country towns, regional centres had DC mains. About 1939 the first towns started moving to AC. I have several Philips (2268 and other models)from late 30's, an STC 633 console (which had been converted from an AC set to run on DC) and a few home built kits.

Not uncommon in Perth?
I wonder if the reason for that is immigration from Europe during that Era, because I know that Perth was the first stop for many immigrants years ago!
A radio would of been a item too expensive to leave behind.

What is the economic balance? The radio I am about to work on has a lot of design there to make it safe. The on/off switch is not mounted on the chassis. Its quite large and made mainly of plastic and screwed onto the wood cabinet. The power is automatically disconnected once you remove the back and the autotransformer is not located on the main chassis, it is screwed onto a wooden plinth .

Was it so much more expensive to have a isolation transformer.

If a company tried to release a beast like this today I doubt it'd make it off the production line.

Today it would be made in China, and would be subject to recall only after someone received a fatal shock (i.e. the first time any regulatory authority became aware of its existence).

Yes many designs went to a lot of trouble to save the cost of a transformer. I'm thinking of a hybrid Thorn B&W TV with a huge tapped dropping resistor (that can't have been cheap) and a system of neons to indicate if the chassis (such as it was) was actually live.

Then the insulated control shafts, screws etc.

I suspect that since transformers were so common here, economies of scale might have helped a bit.

I recall restoring a Japanese-sourced Rincar mantle radio that had an autotransformer to get 100v for the series heaters. The rectifier (50Z3??) had failed so I fitted a proper readily-available transformer that gave me 48 volts for the remaining heaters and added a couple of diodes in a voltage doubler for the B+. And a 3 wire cable and plug. No longer a death trap!

Going transformerless worked well for 220-240v TVs as the optimal B+ could be obtained with just a diode & cap (whereas 110v countries needed a 'voltage-doubler' - costing an extra diode & cap.)

240v also easier to total up series-string filaments for TVs, whereas 110v more suited for direct AC radios' (lower B+)

I suspect that since transformers were so common here, economies of scale might have helped a bit.

I am thinking the same thing. Especially at a time, say from 1950 onwards, when 40Hz mains was disappearing from the landscape, thus giving the larger manufacturers the option of fitting smaller transformers to their radios. When more of one type is made, each transformer becomes cheaper to mass produce.

Also, after the capital cost of a stamping machine to make E's and I's is factored in, the cost of automatically making the bits and pieces becomes smaller as time goes on.

Also series-string TVs required odd voltage valves - not made in Australia - difficult, expensive to import!

In the dying days of B&W TV, National (Panasonic) assembled TVs here using minimally-modified Japanese designs (with a transformer bolted into the bottom of the cabinet!.

Because we were doing warranty service we had to carry all the unique odd-heater-voltage valves that they used. These, and the GE Compactrons, were resented because they expanded the size of the van stock.

We rarely if ever needed the Japanese tubes, same cannot be said of the GE Compactrons.

Those National sets were actually quite poor performers by comparison with the local TVs. Resolution, black level retention, geometry, interlace, picture size regulation were all bested by much more advanced local designs many of which by this stage were all solid state. But they still sold well, which just goes to prove the old adage that if it lights up and moves people will watch it!

We had a National B&W telly when I was a young lad and it popped valves quite regularly, a few times a year it'd go to the local shop for a replacement. The AWA C6333 that replaced it in 1982 went on to serve without so much as a hiccup right up until about two years before analogue television was switched off.

I note that these AWAs and the Thorn equivalents were very simple inside with everything on one board, mounted at the bottom of the cabinet where everything was cool. That would have been rare in those times. Philips tended to use more than half a dozen boards in their sets with some of them close to the hot picture tube.

You should see how many ecaps are in my 1990 NEC!
Its a nightmare! The other issue is that the underside on the main board is covered in Glue snot! It seems to have no flexibility and the ecaps become loose over time in sleeves .
One day when I win lotto I'm going to buy a good desolding gun and have a crack at fixing it For fun.
I just patch it up now ,when it happens.
Pete