Need some help identifying a mid to late '30's floor console. Only name on it is "General" with a sailing ship at the center of a large round multi-colored dial. Tube line up is: 25Z5,43,6F5,76,6D6,6A7 and an L40C ballast tube. Need to locate schematic as someone has butchered a replacement job of the transformer. Many thanks, Jon

Jon, you say that somebody botched a transformer replacement on this set. The tube line-up you describe seems to be for an AC/DC model. If so, the radio shouldn't have a power transformer, but would have a audio transformer for the speaker.

:Jon, you say that somebody botched a transformer replacement on this set. The tube line-up you describe seems to be for an AC/DC model. If so, the radio shouldn't have a power transformer, but would have a audio transformer for the speaker.

Doug, You are correct, stayed up way too late trying to figure this one out. There is an opening under the audio transformer that looks like it fits a power transformer. The chassis must have been made for various circuit types.Still trying to find out who made it and model #. Thanks,Jon.

Though somewhat rare, radio manufacturers did on occasion make a set that used an AC transformer, and yet the tube heaters were wired for series operation directly from the AC line. To determine this, see if the plate(s) of the 25Z5 are connected to one side of the line cord or not (or perhaps to part of the ballast tube which is connected to the line cord). If they are, then this set does not use a power transformer, unless someone modified it. It is more likely that the chassis was used for more than one type of radio, like you say.

Thomas

:Though somewhat rare, radio manufacturers did on occasion make a set that used an AC transformer, and yet the tube heaters were wired for series operation directly from the AC line. To determine this, see if the plate(s) of the 25Z5 are connected to one side of the line cord or not (or perhaps to part of the ballast tube which is connected to the line cord). If they are, then this set does not use a power transformer, unless someone modified it. It is more likely that the chassis was used for more than one type of radio, like you say.
:
:Thomas

Doug,Thomas, As usual your knowledge proves valuable. The set is wired through the ballast then to he 25Z5.The chassis did not look like a factory job but I guess it was made for several kinds. I think I have identified it as from Pacific Radio, model A60B. It is not exact but the schematic makes reference to a 6 tube version that uses a ballast instead of a resistor Again, many thanks fir all your help. Jon.

:Though somewhat rare, radio manufacturers did on occasion make a set that used an AC transformer, and yet the tube heaters were wired for series operation directly from the AC line. To determine this, see if the plate(s) of the 25Z5 are connected to one side of the line cord or not (or perhaps to part of the ballast tube which is connected to the line cord). If they are, then this set does not use a power transformer, unless someone modified it. It is more likely that the chassis was used for more than one type of radio, like you say.
:
:Thomas

Hello Thomas,

Philco in the early 50's had some models that used 6-volt locktal (7B7, 7A8 etc) tubes fed with a filament transformer. The power supply was line operated using a a 7X6 in I believe a half-wave voltage doubler circuit. If memory serves me one was a Philco 51-1730.

Radiodoc

Could the Power transformer step down the fillaments to 25.2 volts instead of 6.3?

25Z5,43,6F5,76,6D6,6A7

The 25Z5 and 43 need 25V. If the other 6 volt tubes are wired in series, and the 43 and 25Z5 in parallel, it would make perfect since for a 25.2 Volt Fillament Transformer.

:Though somewhat rare, radio manufacturers did on occasion make a set that used an AC transformer, and yet the tube heaters were wired for series operation directly from the AC line. To determine this, see if the plate(s) of the 25Z5 are connected to one side of the line cord or not (or perhaps to part of the ballast tube which is connected to the line cord). If they are, then this set does not use a power transformer, unless someone modified it. It is more likely that the chassis was used for more than one type of radio, like you say.
:
:Thomas

Could be, but I think that everything is wired in series with the use of that ballast tube. Don't know why, but I never really knew that the #43 tube existed! I must have just ignored it and assumed that it was somewhat like a #42. Kind of cool finding a 6 pin 25 volt power pentode.

Thomas

:Could be, but I think that everything is wired in series with the use of that ballast tube. Don't know why, but I never really knew that the #43 tube existed! I must have just ignored it and assumed that it was somewhat like a #42. Kind of cool finding a 6 pin 25 volt power pentode.
:
:Thomas

Thomas,

There is another 6 pin tube the #48 with a 30 volt .4 amp filament. A power tetrode.

Radiodoc