I have a Colonial console that doesn't have an identifying mark on it. I need the tube layout. It uses 8 tubes. I've guessed on 5 and need an idea on the other 3. They are 5 pin tubes.
Thanks

Where are the locations of these tubes? What is the voltage from the power transformer when it is plugged in and turned on (no tubes in place)?

It is fairly easy to decipher what kind of tube should be in the socket with the above indications and also by looking at socket wiring. Grid wiring may come from a previous coil or capacitor, and plate wire will go to a successive coil or capacitor, and any resistors connecting here will connect to B+. Pin 2 is often the plate, and pin 4 the cathode. If there is a grid wire on top, grid 3 is probably a screen grid. If there is no grid wire on top, then pin 3 is probably the control grid. This would also indicate whether the tube is a tetrode or triode.

If the socket doesn't appear to have cathode type circuitry wired to pin 4, and the plate appears to connect to the speaker's output transformer, this may be a #47, which has a directly heated cathode (pins 1 and 5). Pin 2 will be the plate, 3 the screen grid, and 4 the control grid.

...Then, once all of the above details have been figured out, it is only a matter of selecting a tube with appropriate voltage and gain ratings, as well as preferred physical characteristics. Also, there is a tube, I forgot the number, which can be substituted for the #27. I like it better because the 27 usually has a mesh type plate (at least with Majestic tubes), and is prone to picking up stray noise, where-as the substitute tube has a solid plate. It's a 5- something.

T.

(What is the *filament* voltage?)

The Colonial 604 is an 8 tube set. Pair of 45's pair of 78's

He mentioned that the remaining three have 5 pin bases. The 45 is a 4 pin and the 78 is a 6 pin.

T.