GE DNF 150W 21V GX7.9

GE 39742 DNF — 150W 21V MR16 Projection Lamp, GX7.9 2-Pin Base

The GE DNF (order code 39742) is a 150W projection lamp rated at 21 volts, built on a MR16 bulb with a GX7.9 2-Pin base and a CC-8 filament. Rated life is 25 hours. Colour temperature is 3400K. Maximum overall length is 1.77 in. Burn position is restricted: Base Down to Horizontal — do not operate base above horizontal. Typical application: 8mm Projection. Projection lamps are matched to specific optical systems — confirm the ANSI code, base, light centre length, and burn position against the equipment before ordering.

Technical Specifications

Product Overview

Projection lamps are precision optical sources. Unlike general lighting lamps, they are built with tailored filaments positioned to close tolerances so that the light source sits exactly where the equipment's optical system expects it. That is why light centre length and burn position appear on the specification alongside wattage and voltage: a lamp with the right base and wattage but the wrong filament position will not focus correctly.

This is a reflector lamp built on a MR-14 (1-3/4 in, 44mm) or MR-16 (2 in, 51mm) dichroic reflector, 2-pin vented base. GE Multi-Mirror® and reflector Quartzline® lamps combine a halogen filament tube with a precision reflector assembled to a rim reference, so the lamp snaps into alignment on installation rather than requiring adjustment. The dichroic coating passes infrared rearward through the reflector instead of forward with the beam, giving a cool beam that reduces heat load on film, artwork, or specimens in the optical path. The faceted reflector produces an efficient, uniform beam with precise control.

Burn position matters on this lamp. It is rated HD: Base Down to Horizontal — do not operate base above horizontal. Operating outside that range shortens life and can cause early failure, because the halogen cycle and the mechanical support of the filament are both designed around the intended orientation.

Compatible Applications

• 8mm Projection (GE listed application)
• 8mm and 16mm projectors
• Microfilm equipment
• Replacement lamp for equipment specified with ANSI code DNF

Before Ordering — Verify

• Confirm the equipment calls for ANSI code DNF. ANSI codes assure mechanical and electrical interchangeability between manufacturers, so this is the primary cross-reference.
• Confirm the base is GX7.9 2-Pin.
• Confirm the supply is 21V. Supply voltage variation significantly affects lamp life.
• Confirm the equipment accommodates a maximum overall length of 1.77 in. Listed lengths include maximum tolerances, so actual lamps are generally slightly shorter.
• Confirm the equipment holds the lamp in a permitted burn position. This lamp is rated HD: Base Down to Horizontal — do not operate base above horizontal.
• Typical working distance is 2.75 in from the reflector rim to the film plane in the optical system this lamp was first designed for. Confirm against the actual equipment.
• Note the 25 hour rated life when planning spares. Rated life is a laboratory median at rated voltage, not a service life guarantee — shock, vibration, voltage fluctuation, and temperature can all shorten it.
• Confirm case quantity — the manufacturer case quantity for this order code is 24.
• GE lists warning and caution notice A against this lamp. Refer to GE's published notices for this order code before installation.

Safety and Handling Guidelines

• Disconnect power and allow the lamp to cool completely before handling or replacement. Projection lamps run at high temperature and stay hot well after switch-off.
• Do not touch the quartz envelope with bare hands. Skin oils cause localized overheating of the quartz and can lead to premature failure or rupture. Clean with isopropyl alcohol if the envelope is touched.
• Quartz halogen lamps operate under pressure. Operate only within an enclosed housing or the equipment for which the lamp is specified.
• Seat the lamp fully in its socket. A partially seated lamp can arc at the contacts and overheat the lampholder.
• Observe the HD burn position restriction. Operating outside the permitted orientation shortens life and can cause early failure.
• Ensure the equipment provides the cooling airflow it was designed with. Projection lamps depend on forced or convected air to stay within their thermal limits.
• Keep combustible materials clear of the lamp and lamphouse.
• Do not exceed the rated voltage. Overvoltage operation sharply reduces lamp life.
• Follow the equipment manufacturer's instructions for lamp installation and alignment.
• This lamp contains no mercury. Recycle or dispose of it in accordance with local requirements.

Compliance

• GE warning and caution notice reference: A. Refer to GE's published notices for this order code before specification or installation.
• Contains no mercury. Not subject to mercury lamp disposal or shipping restrictions.
• Rated life is stated per ANSI standard design life.
• Dispose of in accordance with local regulations.

Ordering Information

• Brand: GE Lighting
• Order Code: 39742
• Description / ANSI Code: DNF
• UPC: 043168991438
• Family: Quartzline® Reflector Lamp
• Case Quantity: 24
• Lamp: 150W, 21V, MR16 bulb, GX7.9 2-Pin base, CC-8 filament
• Dimensions: 1.77 in MOL
• Rated Life: 25 hours
• Burn Position: HD
• Related lamps in this family: BHB (250W 120V, order code 40658); DNE (150W 120V, order code 40161); ELS/ELR (50W 18V, order code 41885); EMM/EKS (250W 24V, order code 40017)

For wholesale pricing, bulk availability, or help confirming the correct replacement lamp, contact ADL Supply at 1-800-235-3489.