Triad Magnetics F-54X Filament Transformer

The Triad Magnetics F-54X filament transformer is a 52.5 VA, chassis-mount power transformer that provides isolated low-voltage AC power for filament and heater circuits from a 115/117 VAC input. It features a center-tapped secondary of 17.5-0-17.5 VAC (35 VCT) capable of up to 0.8 A, making it suitable for powering vacuum-tube filaments in audio amplifiers, radio transmitters, laboratory instruments, and other equipment requiring isolated filament power. With 50/60 Hz operation, 1500 Vrms isolation, and Class B insulation rated to 130°C, it uses a laminated core and wire-lead terminations for straightforward chassis installation. Common replacements include Hammond Manufacturing 166 Series Filament Transformer, Stancor P-6013 Filament Transformer, and Triad Magnetics F-40X Power Transformer, reflecting its use in vintage and contemporary tube-based electronics. Applications span vacuum tube equipment, electronic power supplies, and lab or test equipment across industrial electronics, communications gear, and audio systems.