OPALRAY 12 Volts Low Voltage LED Candelabra Bulb, AC/DC 12V, 6W 600Lm, Dimmable, Warm White Light, E12 Small Base, Frosted Glass Flame Tip, 60W Incandescent Equivalent, 12V-24V DC Power Supply, 3 Pack. 4.5 out of 5 stars. 38. $21.99. Hammond 300BX Power Trans for Mullard 5-20always best to power up the amp with a variable DC power supply and check the current draw so from there one can choose the best drop-in Power Transformer to use. If I recall correctly, the 5-20 amp uses a 470 Ohm, 3 watt (use a 5 watt, better choice) power resistor in the Cathode of each power tube bypassed by a 50 uf Electrolytic cap.
The most useful project I built was a bench power supply giving +400, +200, and 0 or +/-200v B+ and 6.3 regulated heater voltage and a -5 to -100 volt bias supply at a few mA. I had a variac feeding an industrial control transformer and a bridge rectifier through a series wired two prong female AC socket I could use a lamp in as a current limiter. Low Voltage Transformers:30 to 200 voltsTortran vacuum tube amplifier transformer. Center epoxy potted with 3/8" mount hole. Dual primaries 115v (230v in series) 50/60Hz 740va. Five secondaries 390v C.T. at 1.5 amps, 195v at 0.5 amps, 14.8v at 2 amps, 6.3v at 3.6 amps, 64v at 0.1 amps. 6.1"DIA x 3"H, 14 lbs. Low Voltage Transformers:6 to 7 volts - Surplus & SalesLow voltage 6 to 7 volt power transformers in a variety of sizes available and in stock from Surplus Sales of Nebraska. 500ma, (No load 9.5v, 3ma), 74% eff. For 110v supply power, primaries must be parallel; for 230v operation, primaries must be in series. OD:47.mm ID:6.mm x 21.5mm H Filament Transformer 115V @ 50-400 Hz to 6.3V @ 4
Adding 10% to 6.3V gives 6.9 Volt, and 10% is indeed the theoretical maximum over heating of a Barium Oxide tube, with the a compromise on use hours, but no heater breakage. Go above, so 11% or more will break the heater unexpectedly. 7.5 Volts is 19% (!!) above 6.3 Volts. Power Supplies Jaycar Electronics12V DC 10A Desktop Power Supply 2.1mm DC Plug. CAT.NO:MP3241. High current switchmode desktop power supply. Suitable for various power requirements, including large surveillance systems to replace a number of sma $89.95. Bulk Pricing:1-4. $89.95. 5-9. Talk:DIYbio:Notebook/Open Gel Box 2.0/Power Supply This power supply is particularly suitable for operating cathode ray tubes that require 0-5000V, DC. It delivers a maximum current of 60 A, with less than 0.3% ripple. A voltmeter on the front panel is calibrated from 0-6 kV. Output is continuously variable from 100-5000V, DC. This unit also supplies 6.3V, AC at 2 A to operate filament tubes.
DVE Model DV-1241. Class 2 transformer. Input:120Vac, 60Hz, 10W. Output:12.5Vdc, 410mA. 6' cord with coax power plug, Westinghouse Electric 70V-200V 6.3V 9A Tube Amplifier Find many great new & used options and get the best deals for Westinghouse Electric 70V-200V 6.3V 9A Tube Amplifier Power Transformer at the best online prices at ! Free shipping for many products! Westinghouse Electric 70V-200V 6.3V 9A Tube Amplifier TUBE AUDIO AMPLIFIER PREAMP 400 200 VOLT DC POWER SUPPLY 6.3V FILAMENT 300B KT88. £57.11 + P&P + P&P + P&P. Western Electric Type KS-21 Power Transformer for 124 tube amplifier Details about Westinghouse Electric 70V-200V 6.3V 9A Tube Amplifier Power Transformer. Westinghouse Electric 70V-200V 6.3V 9A Tube Amplifier Power Transformer
Four 6.3V outputs at 1.5 amp, 3 amp, and 6 amp. One 225V AC output at 25 milliamps, and One 400V AC at 120 milliamps. In the olden days, transformers commonly specified output voltage in DC assuming the user would be adding full bridge rectifiers. So the 400V DC @ 120mA would be the final output capability of this transformer.