Sensibly equivalent¶ to:
The Pen36C audio output pentode is a B7 version of the CL4. The CL4 has a Ct8 base and the valve was also issued with an International Octal base as the CL33. The B7 base was issued in 1933 and this valve was designed in 1935.
This exhibit has a slightly narrower envelope compared to Pen36C.
Jeff Harrison writes: the Pen36C is a 200 mA heater type pentode for an 1937 Ecko radio AD38 of 1937. It was used in a lot of pre-war Ekco radios like the AD65 and AD75 round radios. Also the Ekco AD38 TRF radio, quite late for a TRF radio.
Mullard tended to add the Suffix -C to a type fitted with a non-standard base cap for sale in a particular market and this may be true here. If so the valve originated with Philips in Europe.
The classic envelope is 42 mm in diameter and, excluding the B7 base pins, is 116 mm tall.
References: Data-sheet & 1043. Type Pen36C was first introduced in 1935. See also 1935 adverts.
Absolute Maximum Operating Conditions¶
Updated January 03, 2022.