Product Overview
B30C600-B Siemens Selenium Bridge Rectifier 30V AC 600mA Full-Wave Bridge for Vintage Tube Audio and Radio Restoration
Condition
Single unit available. Unused NOS sourced from the estate of a private maker's workshop. Condition is excellent — no visible damage, corrosion, or anomalies. Evaluation: Visual inspection only. Function testing not performed. No documentation included.
Ships same business day from Idaho. Packed carefully.
Product Overview
Siemens Semiconductor Group B30C600-B. Full-wave bridge rectifier built on selenium chemistry — not silicon. Rated 30V AC input, 600mA continuous output. The -B suffix denotes the flat-package form factor with four solder terminals marked +, -, and ~ ~. Produced during the era when selenium bridges were the standard power supply component in European and American tube electronics. Unused old stock in this form factor is increasingly difficult to source.
Key Features
- Maximum AC input voltage: 30V
- Maximum DC output current: 600mA (0.6A)
- Circuit type: Full-wave bridge
- Chemistry: Selenium — period-correct, not silicon
- Package: Flat-pack with four solder terminals (+, -, ~, ~)
- Brand: Siemens Semiconductor Group
Applications
- Period-correct restoration of vintage tube receivers and amplifiers (Fisher 500C, 800C)
- Repair and restoration of vintage German radios — Grundig, SABA, Telefunken
- Replacement in early test equipment using low-voltage selenium bridge power supplies
- Collectors preserving original chassis appearance and component authenticity
Frequently Asked Questions
Will this drop directly into a Fisher 500C or similar vintage receiver?
The B30C600 series was used extensively in Fisher 500C and 800C receivers and similar low-voltage tube audio power supplies. Verify the terminal spacing and mounting orientation against your chassis before installation — the -B flat-pack may differ from the original unit's form factor.
Can I substitute a modern silicon bridge for this part?
A silicon bridge is not a direct drop-in. Selenium rectifiers have a higher inherent forward voltage drop than silicon. Substituting silicon without adding a series resistor will raise the DC output voltage and may stress downstream components. Restorers who require period-correct appearance and voltage characteristics specifically seek selenium units like this one.
What is the forward voltage drop of this unit?
Not confirmed. Forward voltage drop in selenium rectifiers varies with age and use history. Verify output voltage under your actual load conditions before committing to a restoration.
Is there a safety risk with selenium rectifiers?
A failing or overloaded selenium rectifier can release toxic fumes with a distinct sulfur odor. This is a known characteristic of selenium chemistry. Inspect the unit visually before installation and operate within the rated 30V AC / 600mA limits.
Sourced from a private maker's estate — this is the kind of NOS part that rarely surfaces in this condition. One unit only.
