Sensibly equivalent¶ to:
15A2 41MPG A80 A80A CV3576 FC4 FCH MH4105 VHT4 X42
The MX40 is a 1934 Osram frequency changer of heptode construction and some of the grids are clearly visible in the picture.
The British radio industry was slow in adopting the superhet for a variety of reasons one of which was that British valve manufacturers were slow in developing the specialised types of valve required in an efficient, low-cost set.
The American radio industry showed the way and the MX40 is simply a home-brewed copy of the American 'pentagrid converter' frequency changers popular there in the early 1930s.
The oscillator voltage was designed to be 10.0 V peak to peak.
The balloon envelope is 43 mm in diameter and, excluding the B7 base pins, is 115 mm tall.
References: Datasheet, 1040 & 1043. Type MX40 was first introduced in 1934.
Absolute Maximum Operating Conditions¶
Updated December13, 2012.