NOS 6BE6 EK90 Zaerix Vacuum Tube in Original Box
For vintage electronics restorers, radio amateurs, and collectors, authenticity and performance are non-negotiable. The NOS 6BE6 EK90 Zaerix Vacuum Tube represents an important piece of broadcasting history. This vacuum tube, also known by its European designation EK90 and British military designation CV453 (visible in the glass marking), is a miniature 7-pin (B7G) pentagrid converter heptode.
Technical Applications and Uses
Primarily designed for use in AM superheterodyne radio receivers, this tube performs two critical functions:
Local Oscillator: Generates the internal radio-frequency (RF) signal.
Mixer: Combines the incoming antenna signal with the local oscillator signal to produce the Intermediate Frequency (IF), typically 455 kHz.
It is a key component in the famous “All American Five” (AA5) circuit topology and mid-20th-century communications equipment.
Brand History: Zaerix
The Zaerix brand is an acronym for Z&I Aero Services Ltd., a historic company based in London, England. Operating primarily from the 1950s through the 1980s, Zaerix did not own glass manufacturing facilities; instead, it operated as a high-end distributor and rebrander, supplying tubes to British government ministries and the aviation sector. Zaerix-labeled tubes were often manufactured by major European companies such as Mullard, Tungsram, RFT, or Soviet factories, selected under strict quality-control standards. The CV453 marking on this tube indicates its approval under the British Ministry of Defence Common Valve system.
Product Condition and Testing
This NOS 6BE6 EK90 Zaerix Vacuum Tube is New Old Stock (NOS), meaning it has never been used in a circuit and retains its original cardboard box, adding value for collectors. Although this is a vintage component, for your peace of mind, the tube has been tested using a basic B&K Precision tube tester. The test verified that there are no internal shorts, confirmed heater continuity, and checked for functional emission levels.
Technical Specifications
Tipo de Tubo: Heptodo Conversor de Pentarrejilla (Pentagrid Converter).
Base: B7G (7-pin miniature).
Voltaje del Filamento (Vf): 6.3 Voltios (Ideal para sistemas de calentadores en paralelo).
Filament Current (If): 0.3 Amps.
Maximum Plate Voltage (Va max): 300 Volts.
Plate Dissipation: 1.0 Watt.
Direct Equivalents: EK90, CV453, 5750 (premium/rugged version), X77.
(FAQ)
Q: Is this tube used or new?
A: It is NOS (New Old Stock). This means it is a tube manufactured decades ago but never sold to the end consumer or used in a device. It is new in its original period box.
Q: What does the CV453 marking on the glass mean?
A: CV stands for Common Valve. It is a designation used by the British Ministry of Defence, indicating that the tube was manufactured to military-grade specifications.
Q: Can I directly replace an EK90 tube with this 6BE6?
A: Yes, directly. 6BE6 (American RETMA nomenclature) and EK90 (European Mullard-Philips nomenclature) are exactly the same electronic tube. They are 100% interchangeable (drop-in replacement).
Q: How do you guarantee that it works if it is so old?
A: Before shipping, the tube is tested using a B&K Precision tube tester to rule out internal shorts and ensure that the filament lights properly, confirming its functional condition.
