Just purchased what I think is a model 248 AWA Radiola console (same as http://vintage-radio.com.au/default.asp?id=photos) and there is no on/off switch which seems a little odd. Does anyone have a circuit diagram or any ideas of why there would be no on/off switch.

Schematic is available for downloading from this page:

http://www.kevinchant.com/model-numbers-201---3001.html.

It was not unusual for early mains powered radio sets to lack an on /off switch. Other than perhaps for cost saving, I can't say why that was.

Power switches have to guarantee isolation of the active rail on an appliance. Because many radios were fitted with bayonet adaptors instead of three pin plugs manufacturers had a choice of fitting a DPST switch or nothing, so the latter was most often selected at the lower end of the market, to save on costs. Radiograms and consoles, particularly those with large speakers, shortwave and more than five valves were considered luxurious and thus came with a power switch.

There's another argument in favour of the switchless radio with a bayonet plug. If the radio has a switch that is in the off position, you won't know whether the bayonet socket is live or not, say you are in the habit of sharing the bayonet socket with a lamp or other appliance, as was often the case back then. A live bayonet socket is a dangerous thing for fingers fumbling in the dark.

Maven