mcmichael: Super Range Portable four: Schematic

There are a few Schematics allegedly of this model available. All apart from a photo copy I have of a simplified schematic of Version "C" from McMichael seem to be either self drawn (only one found even close) or later models. Often the self drawn versions have added resistors so that the Grid Bias supplies and HT1 are not used allowing just a single 120V pack and 2V pack. Some of these modifications could of course date to 1940s, or be by the person drawing the modern schematic.

I have compared the actual McMichael Super Range Portable Four C [(with tuning dial)] schematic (uploaded) with my Model which I beleive to be unmodified (just a wire replaced before I received it). The McMichael Schematic doesn't show the "tone" control (likely because it's in the lid), Aerial/Earth connections, Phone jack or the L7. The McMichael Schematic also doesn't show that the 2nd RF tuning and regenerative feedback unit adjustment  actually consists of six coils. I used the same designations but split as "a" and "b".

The McMichael Schematic also gives R2, a pair of wire wound resistors, a single designation, omits LT + power switch. R1 is actually two half travel Wire wound pots in parallel with three cams on a shaft to operate S1, S2 and S3. On MW all switches are closed and on LW only S2 is closed. No doubt S2 is in the middle to help with isolation between 1st RF tuning (Loop coils & C1) and 2nd RF tuning (Regeneration coils and C2)/

The correct Schematic for my version of the model has L7, a choke (coil) on V2 filament supply. On my version of the Schematic I have explained the aerial socket series capacitor (it's part of the connector) and shown the headphone jack switching which is obviously for high impedance (2K to 4K) headphones. The "Barrel" is +120V and "Tip" is V4 Anode. I have also uploaded a photo of the chassis with all component designations shown. These designations are not entirely logical to me, but copy the Super Range Portable Four C [(with tuning dial)] schematic from McMichael I uploaded. The additional changes are showing Aerial coupling capacitor, adding new designation L7 (missing entirely), S1, S2, S3, splitting R2, L3, L4 and L5.

L7 appears to be original on my version of the Model.

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