Hello Everyone,

I have a Majestic 91 that is in need of a power supply. I believe it is the 9-P-6 Power Unit. Does any one have one available? Thanks!

-Nate

If you cannot find a power supply, you can build one fairly easily using parts from www.tubesandmore.com. They sell a power transformer that would fit the bill well. If you still need extra filament amps., purchase an extra 2.5 volt filament transformer with center tap. Chokes are also available from the above source. You may need to adjust the 1st choke's value a bit if the H-V winding in the new transformer isn't exactly the same as that in the original transformer. Use electrolytics that are rated at least 40 volts above the transformer's H-V AC rating. I think it's rated for 350-0-350 volts, so use 400 volt electrolytics. The original electrolytics (or were they non-electrolytic??) had low values--1 and 2 MFD. You may use higher values in the power supply. You may even use one directly from the rectifier cathode to the transformer center tap. This electrolytic should be about 16 to 20 MFD. The second should be about the same, and the remaining ones can be 10 MFD units. You may need to increase the value of the 1st choke, or simply add an additional 5 watt resistor in series with the 1st choke, because using larger value electrolytics will likely increase your output voltage. Using higher values will reduce hum, though.

If you build the power supply to original specifications, use the original small values, as this is a tuned power supply, from a time when high value electrolytics weren't too common yet. It will likely function well as original, though there may be a bit more hum. Some of these tuned power supplies, however, were excellent, and had no hum dispite the small value condensers used.

Thomas

Also, if you build the power supply using original condenser values, you probably should not add an additional condenser from the rectifier cathode to B-. Since this is a tuned power supply, and small condenser values are used, placing a condenser here may actually increase hum (it may or may not).

Thomas

:Hello Everyone,
:
:I have a Majestic 91 that is in need of a power supply. I believe it is the 9-P-6 Power Unit. Does any one have one available? Thanks!
:
:-Nate

Nate, Post your email address, I have a 9P6 power unit though it does'nt have the # 80 tube. I don't know if it works, the set was given to me as a salvage set. The chassis and speaker are there if you want them too. Jon.

::Hello Everyone,
::
::I have a Majestic 91 that is in need of a power supply. I believe it is the 9-P-6 Power Unit. Does any one have one available? Thanks!
::
::-Nate
:
:Nate, Post your email address, I have a 9P6 power unit though it does'nt have the # 80 tube. I don't know if it works, the set was given to me as a salvage set. The chassis and speaker are there if you want them too. Jon.

Great! I would be interested. Contact me at 'hobby.box at gmail.com'

Thanks,
Nate