08-02-2016, 11:37 AM
(08-02-2016, 10:23 AM)Yorkie Wrote: The circuit of the set contains an error in the it shows the filament being fed from 'point B' yet there is no such point shown. The actual feed point for the 1V4 heater is tag 6 on the auto-transformer, which the circuit shows as going to ground.
David, there is still an error in your redrawn circuit - the other end of the filament winding is floating!
If the filament of the DM70 is on tag 6 then tag 7 must be ground. This means that the tags 6 & 7 on the schematic are reversed and tag 6 is Point 'b'.
The revised schematic should look like this:
