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EBL21

Sensibly equivalent to:
DN143
    
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The EBL21 is one of very few double diode audio output pentode valves that were designed.
The valve has a common cathode and the diodes are for signal rectification for detector or AGC service. As an example of both use and date, this valve type was used in the 1947 Philips 462A radio for detection and audio output. It would have needed considerable drive at the intermediate frequency and the output pentode is of high gain to allow the use a a single stage from detector to output transformer.
Mullard describe the EBL21 as a high sensitivity output pentode, combined with twin diodes, for use in AC mains operated equipment.
The wide glass tube envelope is 32 mm in diameter and, excluding the B8B base pins, is 76 mm tall.
References: Datasheet, 1040 & 3002. Type EBL21 was first introduced in 1947.

 

Pin Connections
B8B
1
2
3
4
5
6
7
8
h
a
g1
g2
a(d2)
a(d1)
k
h

 

Absolute Maximum Operating Conditions
Pentode
Vh
Ah
Va
Vs
Vg
mAa
mAs
ra
gm
Pout
D
6.3
0.8
250
275
-6.2
44
5.8
50K
9.5
5.5
10%
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated March 21, 2014.
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