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OM4

Sensibly equivalent to:
6R7G AR21 CV1055 DH147 EBC33 NR48 VR55
See also:
Cossor 63SPT 6AL5 & OM4 Advert
    
Extras ▼

 

The Cossor OM4 is a double diode triode of the type used in broadcast superhet radio receivers for signal and AGC rectification and first AF amplifier stage and is equivalent to the Mullard EBC33. This specification was made by several companies under different type designations as well as being supplied to the UK services under a CV number.
The classic envelope is 32 mm in diameter, and excluding the IO base pins is 83 mm tall.
References: Datasheet, 1040, 1043 & 3002. Type OM4 was first introduced in 1940.

 

Pin Connections
IO
1
2
3
4
5
6
7
8
tc
m
h
a
a(d2)
a(d1)
-
h
k
g1

 

Absolute Maximum Operating Conditions
Triode
Vh
Ah
Va
Vg
mAa
ra
gm
6.3
0.2
250
-5
5.5
15,000
2.2
Thanks to Frank Philipse for supplying the above PDF datasheet.
Updated February 16, 2013.
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