CANADIAN MARCONI HOME ENTERTAINMENT -  MODEL 233 and 270 RADIOS

Type:  Battery operated,  7 tube BC/SW superheterodyne receiver.
Frequency range:

540 to 1720 KHz
5.9 to 10.2 MHz
10.2 to 18.2 MHz

Circa: 1947/48
Tube lineup: 1T4 1R5 1R5 1T4 1S5 1S4 1S4
Audio power:

250 mw with single output pentode.
500 mw with duel output pentodes.

Speaker:  Model 233 - 6 inch permanent magnet
                  Model 270 - 10 inch permanent magnet

Input power:

'A' supply - one 1.5 cell
'B' supply-  two 45 volt batteries in series.

With economizer on, A supply provides  0.25 ma
With  economizer off , A supply provides 0.35 ma

With economizer on, B supply provides 11.5 ma
With  economizer off , B supply provides 17 ma

Dimensions: ?

Comment: The basic difference between the 233 and 270 models is the speaker size.  Models 233 and 270 utilize the same chassis and schematic The two output tubes in the last audio stage are connected in parallel. There is an  'economizer' switch to save battery power. It reduces the output from 0.5 to 0.25 watts by disconnecting one of the two AF output tubes.

233_270_01.jpg
Front view . 
Photo via E-bay
 
Contributors or References:

1) Canadian Marconi Service Manual - Volume 2
2) http://www.radiomuseum.org/r/marconi_wi_battery_model_233.html

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Jan 13/14