Uploaded April 2021 | Updated September 2026, 1 hour ago
The Antique Wireless Association has developed a printed circuit board that you can use to build a universal battery eliminator that will supply the A, B and C voltages for vintage battery powered vacuum tube radios, in addition to being a bench power supply for the experimenter.
For more information visit:
antiquewireless.org/homepage/pcb-item-5
=========================================================
The UBE printed circuit board (PCB) measures 6 ¼ by 6 ¾ inches with a maximum height of 2 ¾ inches. Three PCB-mounted transformers along with rectifier and regulator circuitry develop the “A”, “B” and “C” supply voltages. The transformers can be configured for either 120 or 240 VAC operation by installing the appropriate on-board jumpers. As an option, the builder can use off-board chassis mounted transformers if desired. AC mains wiring, fusing and switching are left as an exercise to the builder.
Each supply is isolated electrically from the others as well as chassis ground, to allow maximum flexibility in connecting to a wide array of vintage radio sets. Each supply is also protected against momentary short circuits to its negative rail. However, care must be taken to prevent voltage-to-voltage shorts.
Another important feature of the AWA UBE PCB is the ability to customize the power supply to fit individual needs. The UBE has a number of “B” and “C” output voltages in multiples of +22.5 and -4.5 volts. However, some early radios required only +90 volts plate and 1.25 V filament supplies. For such cases the “C” supply components can be left off, and the “A” and “B” transformers downsized to reduce cost and weight. A simple resistor change in the “B” regulator can be made to lower the +180 V to +90 volts. The rest of the “B” output components associated with the +135 V and lower output voltages can be left off of the board.
The PCB can be mounted inside a project enclosure with terminal strip connections or within the radio cabinet itself, with wires connected directly to the appropriate PCB pads. A line cord, fuse and on-off switch are needed to complete the installation.
The Antique Wireless Association has developed a printed circuit board that you can use to build a universal battery eliminator that will supply the A, B and C voltages for vintage battery powered vacuum tube radios, in addition to being a bench power supply for the experimenter.
For more information visit:
antiquewireless.org/homepage/pcb-item-5
=========================================================
The UBE printed circuit board (PCB) measures 6 ¼ by 6 ¾ inches with a maximum height of 2 ¾ inches. Three PCB-mounted transformers along with rectifier and regulator circuitry develop the “A”, “B” and “C” supply voltages. The transformers can be configured for either 120 or 240 VAC operation by installing the appropriate on-board jumpers. As an option, the builder can use off-board chassis mounted transformers if desired. AC mains wiring, fusing and switching are left as an exercise to the builder.
Each supply is isolated electrically from the others as well as chassis ground, to allow maximum flexibility in connecting to a wide array of vintage radio sets. Each supply is also protected against momentary short circuits to its negative rail. However, care must be taken to prevent voltage-to-voltage shorts.
Another important feature of the AWA UBE PCB is the ability to customize the power supply to fit individual needs. The UBE has a number of “B” and “C” output voltages in multiples of +22.5 and -4.5 volts. However, some early radios required only +90 volts plate and 1.25 V filament supplies. For such cases the “C” supply components can be left off, and the “A” and “B” transformers downsized to reduce cost and weight. A simple resistor change in the “B” regulator can be made to lower the +180 V to +90 volts. The rest of the “B” output components associated with the +135 V and lower output voltages can be left off of the board.
The PCB can be mounted inside a project enclosure with terminal strip connections or within the radio cabinet itself, with wires connected directly to the appropriate PCB pads. A line cord, fuse and on-off switch are needed to complete the installation.
