Ok if you use only primary voltages lower than the rated voltage for the winding.
All of the windings' current ratings will remain unchanged.
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Feeding 120+ volts into a 100 volt winding may make the transformer run hot, maybe even too hot, or it may be OK. This depends on the amount of inductance it has. If the transformer was rated for 50Hz operation and you are running it on 60Hz you are probably OK.
Feeding 120 or so volts into the 240 volt winding will be fine, but the regulation will be a bit worse that normal due to the added winding resistance.
Feeding 120 or so volts into the 240 volt winding will be fine, but the regulation will be a bit worse that normal due to the added winding resistance.
yes, sure, that is correct, but there comes a time when
situations call for such applications, specially if one just want to
use what is available.....
i do this also, sometimes using a variac to get desired voltages...
> a mains transformer works at constant flux
Well, at the flux for its winding and the applied voltage and frequency.
Now we know Mike wants to put 120V into a 240V winding. This is perfectly safe. The flux will be lower than designed. He "wasted" about half his money: an optimum transformer could have been built half the weight. However for minor loads, or when a transformer is already in hand while a "right" transformer means custom plus shipping, there's no "waste".
26E6 is a vacuum tube, made for aircraft with "26V" (12 lead cell and generator) power. Heater is 26.5V at 0.3A. Seems to be a variant of a 6Y6/25L6 type. (Wonder if it is a 25L6 re-rigged for high vibration and fussy flyers?) 200VDC and 61mA at 2.6K gives around 6 Watts output. Will stand 600 Gee from any direction.
http://www.mif.pg.gda.pl/homepages/frank/sheets/127/2/26E6WG.pdf
Personally I'd think to find a 24V 1A-2A transformer. You can even get these in Home Depot (furnace thermostat power: 24VAC, 40VA, 1.6A). At light load it will un-sag nearer 26V-28V. The 26E6 heater range is 22.5V-31V, so not fussy.
Well, at the flux for its winding and the applied voltage and frequency.
Now we know Mike wants to put 120V into a 240V winding. This is perfectly safe. The flux will be lower than designed. He "wasted" about half his money: an optimum transformer could have been built half the weight. However for minor loads, or when a transformer is already in hand while a "right" transformer means custom plus shipping, there's no "waste".
26E6 is a vacuum tube, made for aircraft with "26V" (12 lead cell and generator) power. Heater is 26.5V at 0.3A. Seems to be a variant of a 6Y6/25L6 type. (Wonder if it is a 25L6 re-rigged for high vibration and fussy flyers?) 200VDC and 61mA at 2.6K gives around 6 Watts output. Will stand 600 Gee from any direction.
http://www.mif.pg.gda.pl/homepages/frank/sheets/127/2/26E6WG.pdf
Personally I'd think to find a 24V 1A-2A transformer. You can even get these in Home Depot (furnace thermostat power: 24VAC, 40VA, 1.6A). At light load it will un-sag nearer 26V-28V. The 26E6 heater range is 22.5V-31V, so not fussy.
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The 26E6WG is a rather strange looking tube. It looks like they took the guts from a 25L6 or 25W6, sawed it in half, then mounted each half next to each other and wired them in parallel. The whole thing is stuffed into a ruggedized bottle and base.
I "tested" a pair of them in P-P with the idea of using them in an automotive tube amp. That never happened, so I sold the tubes years ago. If I remember right I was getting over 40 watts from a pair on over 300 volts of plate voltage. Like the 6W6 and 12L6 family, the plate voltage can be abused, but respect the screen voltage. 120 to 130 volts works best.
The easiest way to get here on home AC power is indeed a 24 volt transformer for the heaters, and a voltage doubler on an isolation transformer for plate voltage. The screen voltage comes from the mid point on the doubler. With todays line voltage into a Triad N68-X, I get 165 and 330 volts. That's a bit high for the screen so some means of dropping voltage is needed.....If it were me I would use a mosfet and a gas tube or zener string.
I have also used this setup with other tubes designed for series heater operation, often wiring the tube heaters in series from the 165 VDC source, then tapping the heater string for the output tube's G2 supply.
I "tested" a pair of them in P-P with the idea of using them in an automotive tube amp. That never happened, so I sold the tubes years ago. If I remember right I was getting over 40 watts from a pair on over 300 volts of plate voltage. Like the 6W6 and 12L6 family, the plate voltage can be abused, but respect the screen voltage. 120 to 130 volts works best.
The easiest way to get here on home AC power is indeed a 24 volt transformer for the heaters, and a voltage doubler on an isolation transformer for plate voltage. The screen voltage comes from the mid point on the doubler. With todays line voltage into a Triad N68-X, I get 165 and 330 volts. That's a bit high for the screen so some means of dropping voltage is needed.....If it were me I would use a mosfet and a gas tube or zener string.
I have also used this setup with other tubes designed for series heater operation, often wiring the tube heaters in series from the 165 VDC source, then tapping the heater string for the output tube's G2 supply.
I also happen to have a 25V 2A filament tranny on hand. 
I like the idea of tapping a heater string for G2. No problem with uneven heating from the tap in your experience? I plan on using this tranny for experimentation. It was used for a guitar amp prototype (similar to Marshall 18W) and rings out with the following AC voltages driven by 120V...
Input Red Red/Y
Bl-Gr 178 137
Bl-Bu 322 216
Bl-Br 386 314
IIRC it was rated for around 130mA on the secondary. I think the R/Y is intended for screen supply but IIRC is a tap on the main secondary winding. Has 5V and 6V windings for other heaters.
I Will need new tranny for the actual amp as I don't have anything capable of enough current for stereo P-P or stereo SE BiAmp. Another option is a full 300V B+ from one tranny and use one of the many SS type trannies I have with a multiplier for screen supply. I have a 1:1 PT but it is from a console with SE 6BQ5 so not enough um pa pa for a quad of these guys.
I like the idea of tapping a heater string for G2. No problem with uneven heating from the tap in your experience? I plan on using this tranny for experimentation. It was used for a guitar amp prototype (similar to Marshall 18W) and rings out with the following AC voltages driven by 120V...Input Red Red/Y
Bl-Gr 178 137
Bl-Bu 322 216
Bl-Br 386 314
IIRC it was rated for around 130mA on the secondary. I think the R/Y is intended for screen supply but IIRC is a tap on the main secondary winding. Has 5V and 6V windings for other heaters.
I Will need new tranny for the actual amp as I don't have anything capable of enough current for stereo P-P or stereo SE BiAmp. Another option is a full 300V B+ from one tranny and use one of the many SS type trannies I have with a multiplier for screen supply. I have a 1:1 PT but it is from a console with SE 6BQ5 so not enough um pa pa for a quad of these guys.
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