Filament transformer current question

[six el six]

I just picked up a used 12.6 v  20A center tapped transformer.

My question is will half of the secondary winding (6.3 v) be able to supply 20 amps or will the current handling capability be cut 50% when using half of the winding or ... ?

[FYL]

If the core is rated at 12 x 20 = 240 VA no problemo using it at 6 x 20 = 120 VA. Or use both windings in //, taking care of the phase, for full power.

[PRR]

At 6V 20A it will run not-hot. That's fine.

I can't offhand think of many practical tube projects which could need 6V at more than 20A.

Because half the secondary, a quarter of the copper, is loafing, I'd try it at 25A maybe 30A, checking for heat frequently the first hour and day. But that looks like eighty little tubes, or sixteen big tubes, or 40 small and 8 large... unless you are building an electronic organ all on one chassis, that's more than you ever need.

[six el six]

I can't offhand think of many practical tube projects which could need 6V at more than 20A.

I can't either. I got it because it was cheap and available and I just learned a troubleshooting technique from Sluckey that would necessitate having at least a 6.3@10A winding.

[drgonzonm]

You could use the 12.6 volts on the 12 series tubes.  and series pairs of 6 series tubes. 

My mind wanders thinking of two-phase power on separate and isolated boards, then creating artificial center taps.   Or looking at guitar amp that you could plug into a cigarette lighter.  Totally different group of tubes, and using old radio designs from the 40's and the early 50's. 

maybe twenty amps won't be enough