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VINTAGE NATIONAL (PANASONIC) AUTOMATIC INSULATION RESISTANCE TESTER (MEGOHMMETER)
Model: BN-501TB
Manufacturing Year: 1976 (Showa 51)
Condition: Rare - New Open Box / Only One Available On
Up for sale is an incredibly rare, pristine example of a vintage National Automatic Insulation Resistance Tester, Model BN-501TB, manufactured in 1976 by Matsushita Electric (now Panasonic). This high-quality, professional-grade diagnostic instrument features a 500V test voltage capacity with a maximum scale range of 1000MΩ.
This specific unit was originally manufactured for the Japanese domestic market and is exceptionally hard to find outside of Japan. It is in true "New Open Box" condition—completely unused and safely tucked away in climate-controlled storage since its original production. This is currently the ONLY one available on worldwide in this pristine, complete condition!
PRODUCT SPECIFICATIONS:
- Brand: National Matsushita Electric Industrial Co
- Model: BN-501TB
- Type: Transistor Constant-Voltage Analog Megohmmeter
- Output Test Voltage: 500V
- Maximum Measurement Scale: 1000MΩ
- Power Source: Battery operated (requires AA batteries)
WHAT IS INCLUDED:
- Original National BN-501TB Testing Unit
- Original Hard-shell Black Leatherette Protective Carrying Case
- Separate Zippered Probe/Lead Accessory Pouch
- Original Operator Instructional Paperwork & Diagrams
- Original Retail Box with Classic Graphics
CONDITION DETAILS:
- Exterior: Immaculate. Free of field grime, scuffs, scratches, or wear.
- Battery Compartment: Pristine condition with absolutely zero battery leakage or terminal corrosion.
- Original Box: Structural integrity is excellent; shows minor edge wear/aging from storage, but the colors and text are incredibly sharp.
This is a museum-grade piece of industrial history that would look phenomenal on display or serve as a pristine flagship addition to a vintage tool or test equipment collection. Don't miss out on this unique opportunity to own a flawless piece of 1970s Japanese engineering!
Please review all photos carefully to confirm the exact aesthetic condition and inclusions. Item will be meticulously padded and packed to preserve the original retail box during transit.
