▼ Menu

Universal

 
See also:
Myers Universal Box - Myers Valves Advert - Myers Valves Advert - Myers Valves Advert - Myers Valves Advert
    
Extras ▼

 

The Universal triode from Myers is of double ended construction to reduce inter-electrode capacitances and was a successful product. It was also known as the RAC-3 and is a bright emitter. It was later superseded by the dull emitter Dry Battery valve.
Initial introduction was in Canada in 1922. However Myers had worked with De Forest, RCA etc in the USA making valves and infringing patents along the way. Technically a good valve the company moved back to the USA after the expiration of the De Forest patents but legal action by RCA for back royalties drove the company to bankruptcy.
The attached .PDF file is a reproduction of a 1924 article from Wireless World.
The red end has connections for the anode and the f+ connection. The black end has connections for the negative end of the filament and the control grid.
Looking at the evacuation pip. The electrodes are held in place within glass beads.
The special base was probably made of ebonite.
The valve in place within the special holder.
art of the leaflet that wrapped the valve within the box. See here for a .PDF of the whole sheet.
Elman B Myers.
Thanks to Louis Vermond for sending these images.
The thin glass tube envelope is 16 mm in diameter, and including the base pins is 84 mm tall.
References: Datasheet, 1047 & 3002. Type Universal was first introduced in 1922.

 

Absolute Maximum Operating Conditions
Triode
Vh
Ah
Va
Vg
4.0
0.8
40-90
-1 to -10
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated June 26, 2017.
Return to Main Index