Mazda Nickel Stripe Instant Start MCFA/U

It is found that the voltage necessary to strike a fluorescent tube is lowest when the electrical resistance along the lamp is either very low, or very high. If it has a medium resistance the lamp can be very troublesome to strike. Two types of tube were thus developed to ensure satisfactory resistance.

The first was the MCFA lamp, featured here, in which the resistance is kept as low as possible. A nickel stripe is affixed to the outside surface of the glass, running the entire length of the tube, and in electrical contact with both end caps.

The second was the MCFE lamp, almost universally used today, in which the outside surface is coated with a silicone layer. This breaks surface moisture films which might otherwise result in a troublesome medium-resistance path.

Neither approach is perfect, and some further assistance is needed in the form of an earth connection alongside the lamp. In the case of metal stripe tubes, the end caps are simply earthed. With siliconed tubes it is found that the earthed metalwork of the luminaire is adequate, if it is no more than half an inch away from the tube, and at least one inch wide. Before the tube strikes, the weak electric field between one electrode (at mains potential) and the earthed body results in some ionisation which assists tube starting.

A small market remains however for metal stripe tubes in cases where no earthed metalwork is available. They are also preferred in industrial applications where the tube may become very dirty, such that the silicone film no longer works. Additionally, certain instant-start circuits require these tubes, which must be started with a lower voltage.
Manufacturer: A.E.I. Lamp & Lighting Co. Ltd.
Lamp Power: 40 Watts
Lamp Current: 0.88 Amps
Lamp Voltage: 45 Volts
Cap Type: G13 x2
Bulb Finish: Warm White
Bulb Type: T-38 T-12 in eighths/inch
Overall Length: 600 mm 24 inches
Light Centre Length: N/A N/A
Discharge Length: 525 mm 21 inches
Electrodes: Stick Coil with balled ends Triple carbonate emitter
Atmosphere: Ar | Hg
Luminous Flux: lm @ 100 hours lm Average to 5000h
Luminous Efficacy: lm/W @ 100 hours lm/W Average to 5000h
Colour Temperature & CRI: CCT:3000K CRI:Ra=54
Chromaticity Co-ordinates: CCx:0.435 CCx:0.401
Burning Position: Universal
Rated Lifetime: 5000 hours Economic life
Warm-up / Re-strike Time: 1 minute Instantaneous
Factory: Leicester England
Date of Manufacture: July 1962 Date Code2555
Original / Present Value: £0 9s 3d (1963) £6.30 (2004)
References: 1) AEI Mazda Catalogue of GLS, Fluorescent & Discharge Lamps, 1963.
2) Electric Lamps Volume B, The British Lighting Council, 1967.