Sensibly equivalent¶ to:
The 1T4 is a miniature screened pentode for dry battery operation. It was designed for radio reception and is a variable μ RF device.
This valve was purchased new in 1963 to build a one valve broadcast receiver. The design was by Gilbert Davey from an excellent book 'Fun With Radio'. High impedance headphones were mandatory and a pair of Brown type F were available. Many hours of clandestine Radio Luxemburg were enjoyed under the bed clothes until the Ever Ready 90 Volt HT battery died. A cheap Far Eastern transistor radio was then cheaper than a new HT battery.
The thin glass tube envelope is 19 mm in diameter and, excluding the B7G base pins, is 46 mm tall.
References: Data-sheet & 1040 Type 1T4 was first introduced in 1940.
Absolute Maximum Operating Conditions¶
Updated February 04, 2013.