Airline/valco power transformer(heater wire question)

[fopoman]

Frankenstein amp alert!!!

The power transformer has one green heater wire. I'm building a champ clone. Does the grey wire need to go to ground? Does the green wire go to the pilot lamp then pin two on the octal then 4 to 5 on the noval socket like the champ layout? Is there a better way to run a single wire to the heaters?

Sorry for the run on sentences and thank you

[martin manning]

Original Champs ran a single filament wire daisy chained from the transformer to the pilot lamp to the 6V6 to the 12AX7, with the remaining heater pin on each socket grounded locally. The pilot lamp was grounded through its mounting bushing, and the other heater winding lead was grounded with the HT center tap. That's not the best arrangement, and most people will run both heater leads to an isolated pilot lamp holder, and a twisted pair from there to the tube sockets. If there is no CT on the filament winding, a 100Ω resistor is soldered from each lug on the pilot lamp holder to ground.

[fopoman]

So if I were to build a tweed champ... Using the one green heater wire in series to the pilot, octal and novel... I could still use a pair of 100 ohm resistors to ground from the pilot lamp. The grey wire would go directly to ground?

Thanks again for your assistance

[martin manning]

If you use the one wire, locally grounded scheme like the original Champ, the ground reference is already taken care of and you don't need the 2x 100Ω.

That's a really bad picture, but I think I see: two red leads and a red yellow lead, which would be the high voltage secondary; two yellow, which would be for a 5V rectifier filament; two green, which would be for 6.3V filaments, and two black, which would be the primary. Have you made any measurements and/or checked voltages?