Raytheon 866A mercury-vapor rectifier · pair
The blue-glow half-wave rectifiers of the golden age of ham radio. Handled with respect.
- SKU
- MS-VT-0426
- Era
- 1900-1950
- Condition
- Recently sold — inquire for similar
- Dimensions
- 175 × 55 mm (H × Ø) each
- Weight
- 95 g each
- Provenance
- Consigned 2025 from an estate of a retired ARRL member in Vermont.
- Category
- Vacuum Tubes & Valves
- Tags
- raytheon866amercury-vaporrectifiersold
Half-wave mercury-vapor rectifiers of the sort that turned a 1940s ham station into a small cathedral of blue light when the plate transformer came up. The 866A wants to be pre-heated for a full ten minutes on first fire to distribute the mercury properly along the envelope — a ritual, but one worth performing.
This pair dated to the late forties, Raytheon manufacture, both with the correct four-pin bayonet bases and the visible pool of mercury at rest in the base of the envelope. Filaments were straight, no signs of gassing at the seals, and the internal graphite anode was clean.
They went to a broadcast-transmitter restorer in Melbourne earlier this year. If you have a Collins 30K or a Johnson Ranger with a hungry power supply, we will let you know when the next set surfaces.
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