Frost-Minton 4 PW
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The readings were made with the volume control in the full " on " position.
* These voltages are the correct values. The average test kit will give much lower readings, (as low as 1/10 of these values) due to the low resistance of the meters compared to the high resistance included in the detector plate and screen circuits and the audio grid circuit.
When the volume control is reduced the
RF plate voltage remains constant RF screen voltage increases RF cathode voltage increases RF grid voltage increases
Electrical values Transformer notes
The three leads from the main filter condenser are connected as follows:
By-pass Condenser Assembly
The condensers incorporated in this unit are identified as follows:
Six leads are brought out of the transformer winding on the side next to the terminal strip. Three are located on the opposite side. The transformer is connected as follows:
Primary Winding - Stranded wires, terminal strip side
224 and 247 filaments Heavy wires, terminal strip side
280 filament Small wires, terminal strip side
280 plates Two leads nearest front of set, opposite side
280 center tap - Lead nearest back of set, opposite
The trimmer condenser mounted on the loud speaker must be adjusted for maximum volume.
Some types of the 247 Pentode operate normally with a blue glow. This action does not, therefore, denote that the tube is defective due to gas.
It is very important that no tube is removed from its socket with the receiver " on " as to do this will damage the receiver or the Pentode tube. Make sure that the lead from the top of each 224 tube to the variable condenser follows closely along the metul partition between the tubes. Oscillation may occur if this lead lies too close to the tube itself.