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U149

Sensibly equivalent to:
7Y4 U82
See also:
Pioneers of HT Rectifiers
    
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The U149 full wave rectifier is almost identical to the American Type 7Y4.
By the time this specimen was made the Marconiphone brand had only loose connections with M-OV and purchased their valves from numerous suppliers. This exhibit does not look like an M-OV product.
The maximum reservoir capacitor is 40 µF and the minimum series resistance, for current limiting, is not given in the literature.
The cathode can be seen as a white tube in the centre of the picture. The anodes are mainly fins for heat dissipation.
The wide glass tube envelope is 28 mm in diameter and, excluding the B8B base pins, is 55 mm tall.
References: Datasheet & 1040. Type U149 was first introduced in 1950.

 

Pin Connections
B8B
1
2
3
4
5
6
7
8
h
-
a(2)
-
-
a(1)
k
h

 

Absolute Maximum Operating Conditions
Rectifier
Vh
Ah
Va
mAa
6.3
0.5
325
70
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated December03, 2012.
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