Hi all have a question about the power supply for this model, mine is missing the power supply so I am attempting to make one myself, the schematic shows that there are 2 separate 2.5 supplies one for the 27 tubes and one for the 45 outputs , is this nesasary? I don't think I can find a transformer with 2 - 2.5 supplies , even new, any ideas or a workaround for this?
Thanks
E.

:Hi all have a question about the power supply for this model, mine is missing the power supply so I am attempting to make one myself, the schematic shows that there are 2 separate 2.5 supplies one for the 27 tubes and one for the 45 outputs , is this nesasary? I don't think I can find a transformer with 2 - 2.5 supplies , even new, any ideas or a workaround for this?
:Thanks
:E.
Hi Elton,
This was done because the 45's have filaments that are also cathodex, like the 5Y3GT or 1F6G.
To properly bias the 45's they needed to be separated from the filaments of the 27's which most likely have a lead grounded.
If the 45's filaments also lit the 27's feedback of signal from the 45's to 27's is possible. Not good.
The only work around I can think of is a second transformer.

Best Regards,

Bill Grimm

Elton,
I restored an Edison R7 whose schematic showed 3ea 2.5VAC windings on the transformer. One for the RF stages (27), one for the detector only (27) and one for the 45 PP output. Upon close examination, found only 2 windings, but 45's were separate from the TRF. The hum balance circuit for the 45's might affect the other tubes and volume control.
Try PTOP "oldradioparts.com. Gary has a plethora of old stuff, including transformers.

marv

:Hi all have a question about the power supply for this model, mine is missing the power supply so I am attempting to make one myself, the schematic shows that there are 2 separate 2.5 supplies one for the 27 tubes and one for the 45 outputs , is this nesasary? I don't think I can find a transformer with 2 - 2.5 supplies , even new, any ideas or a workaround for this?
:Thanks
:E.

:Hi all have a question about the power supply for this model, mine is missing the power supply so I am attempting to make one myself, the schematic shows that there are 2 separate 2.5 supplies one for the 27 tubes and one for the 45 outputs , is this nesasary? I don't think I can find a transformer with 2 - 2.5 supplies , even new, any ideas or a workaround for this?
:Thanks
:E.

I got the transformer and choke for my Majestic 90 from Radiodaze. The total filament draw is around 9 amps for this baby! No way to repair the transformer secondary short to ground and open spkr field winding. They really liked to pot their components in tar. 5 stages of RF make it a nice sounding and sensitive radio.

Hi Elton

Here is a list of availabler power transformers. Ones with 2.5 volt filaments are toward the end.

http://www.oldradioparts.com/2a23efl.txt

You can use a single 2.5 volt filament winding but need to remove the resistors to ground (1.6 ohm on the schematic) used for other tubes. 45s have their filamemt about 45-50 volts above ground for bias. This voltage would also be ok on filaments of the 27 tubes since they have a cathode isolated from filament.

Norm

:Hi all have a question about the power supply for this model, mine is missing the power supply so I am attempting to make one myself, the schematic shows that there are 2 separate 2.5 supplies one for the 27 tubes and one for the 45 outputs , is this nesasary? I don't think I can find a transformer with 2 - 2.5 supplies , even new, any ideas or a workaround for this?
:Thanks
:E.

:Hi all have a question about the power supply for this model, mine is missing the power supply so I am attempting to make one myself, the schematic shows that there are 2 separate 2.5 supplies one for the 27 tubes and one for the 45 outputs , is this nesasary? I don't think I can find a transformer with 2 - 2.5 supplies , even new, any ideas or a workaround for this?
:Thanks
:E.

I have a parts chassis for a Majestic 90B.
The power transformer, as well as the filter choke are good. I suspect they would work nicely for a power supply on you model 90.
Let me know if you are interested.
They

::Hi all have a question about the power supply for this model, mine is missing the power supply so I am attempting to make one myself, the schematic shows that there are 2 separate 2.5 supplies one for the 27 tubes and one for the 45 outputs , is this nesasary? I don't think I can find a transformer with 2 - 2.5 supplies , even new, any ideas or a workaround for this?
::Thanks
::E.
:
:I have a parts chassis for a Majestic 90B.
:The power transformer, as well as the filter choke are good. I suspect they would work nicely for a power supply on you model 90.
:Let me know if you are interested.
:They
Hi yes I am Interested, would rather have it all original Please feel free to e-mail me and maybe come up with a price?
Thanks