ID:
2081
Maker's Name:
HMV
Where made:
Australia
c. 1955
Dimensions:
33 × 14.5 × 27 cm
Battery powered superheterodyne domestic receiver. Uses 1.5V for filaments(all in parallel) and 90V for high tension. The valve line-up is: converter 1R5, IF 1T4, detector audio 1S5, AF out 3S4.
Consumption HT 22 mA, filaments 250 mA.
The parallel filament arrangment has two disadvantages. First, the grid bias of -7V is provided by a dropping resistor on the negative side of the HT battery, thus wasting a constant 22 mA at 7 V.
Secondly, the carbon/zinc filament battery has internal resistance and the high current drawn means higher internal loss of energy and less energy delivered to the filaments over the life of the battery.
