▼ Menu

UY-227

Sensibly equivalent to:
UY227
    
Extras ▼

 

The type UY-227 triode is also known as the 27. It is an early indirectly heated audio valve with a good reputation for performance.
Westinghouse announced a double ended indirectly heated cathode in an article in 1922. The valve became the UY-227 and the UY base was adopted in 1927. The UY-224 screened grid valve was a development of the UY-227.
With 90 Volts on the anode the grid bias should be -4.5 Volts. At 135 Volts on the anode the bias should be -9 Volts. At the absolute maximum anode voltage of 180 Volts the bias should be set to -13.5 volts. The heater cathode voltage should not exceed 9 Volts.
The anode is a mesh and the supports are substantial rods.
Seen straight on the two mesh anode plates are fixed together by notching. The grid support is on one side of the grid only.
The close-up on the base of the anode shows the cathode cylinder, heater wires and control grid.
The balloon envelope is 42 mm in diameter, and excluding the UY base pins is 96 mm tall.
References: Datasheet, 3002, 1043, 1047 & 1040. Type UY-227 was first introduced in 1927.

 

Pin Connections
UY
1
2
3
4
5
h
k
g1
a
h

 

Absolute Maximum Operating Conditions
Triode
Vh
Ah
Va
2.5
1.75
180
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated October 20, 2014.
Return to Main Index