1920s Mullard PM1 LF Radio Triode Valve In Its Original Box

This amazing collectible is a 1920s Mullard PM1 LF Radio Triode Valve In Its Original Box; where PM stands for Philips-Mullard. It is a dull emittter low frequency amplifier for use with a 2volt accumulator. A nice display item for the office or radio shack!

It is nearly 100 years old, has never been used and hasn't been tested. As a piece of radio history made by Mullard Radio Valve Co. Ltd, Nightingale Lane, Balham, London, it is being sold as a collectible for display only. According to The History of the British Radio Valve to 1940, the valve was first introduced in 1926.

This is a late 1920s version of both valve and box. It has its original paper label with the warning "THERE IS PRACTICALLY NO GLOW FROM THIS FILAMENT" and information about the filament voltage and current, and maximum anode voltage. 

The cardboard box, with the cut out in the lid, is intact with scuffs and blemishes commensurate with age and storage. The colours have faded but are still legible. It comes with its original technical leaflet.

Original Specification:

• Brand: Mullard Radio Valve Co.Ltd etched on the side in white
• Type: Triode Valve For Low Frequency Amplification and Detection
• Marked with BVA and C18
• Base: 4-Pin B4 with a single slot in each pin 
• Filament: 
• Voltage 2.0 Volts
• Current ~0.1 amps 
• Anode Voltage 50-100 Volts

Please click on the following links for more vintage valves and radio ephemera