THORDARSON 21F12 FILAMENT TRANSFORMER 117 VAC 50/60 HZ

Description:

The Thordarson 21F12 Filament Transformer is used in vacuum tube electronic equipment to supply regulated low-voltage AC power for heating the filaments of receiving and transmitting tubes. Commonly installed in vintage tube amplifiers, radio transmitters, communications equipment, laboratory instruments, and custom vacuum tube power supplies requiring a 6.3 VAC center-tapped filament source. Electronic technicians, audio restoration specialists, and system integrators use this transformer for equipment repair, restoration, replacement, and custom tube amplifier construction.

Applications:

The Thordarson 21F12 is designed to provide isolated filament power for vacuum tube circuits while maintaining stable voltage under continuous operation. It is widely used in guitar amplifiers, hi-fi audio amplifiers, amateur radio transmitters, vintage communications receivers, laboratory power supplies, and electronic restoration projects where reliable heater voltage is essential for proper tube operation.

Technical Specifications:

• Brand: Thordarson
• Part Number: 21F12
• Product Type: Filament Transformer
• Primary Voltage: 117 VAC, 50/60 Hz
• Secondary Voltage: 6.3 VAC Center-Tapped (CT)
• Secondary Current Rating: 10 A
• Transformer Type: Isolation Filament Transformer
• Dielectric Test Voltage: 2,500 VAC
• Mounting Style: Chassis Mount
• Lead Terminations: Flying Leads
• Cooling Method: Natural Air Cooling
• Frequency: 50/60 Hz
• Construction: Enclosed Laminated Core Transformer
• Approximate Weight: 2 lb 10 oz (1.2 kg)
• Country of Manufacture: United States
• Typical Applications: Tube Amplifiers, Radio Equipment, Communications Systems, Laboratory Electronics, and Vacuum Tube Power Supplies.

Common Replacements:

• Thordarson 21F204 Filament Transformer
• Thordarson 21F193 Filament Transformer
• Thordarson 21F103 Filament Transformer