The valve count was reduced to 4 by using a 1D8, which was used as a triode amplifier and pentode power amplifier. The RF amplifier was a 1J6 feeding a 1P5. The RF output was fed to another 1P5 acting as detector. The resultant audio was fed to the triode of the 1D8.
The design of the audio circuit made provision for an intercom amplifier.
Power requirements were 1.4v for filaments and 90v for HT.
Unfortunately during the re-design some unforseen problems were introduced which made the AR14/AT10 rather a disaster. The directly heated filament tubes were mounted on their sides and quite often failed to operate. The vibrator power supply associated with the AT10 proved to be monumentally unreliable at high altitudes. Failure of the equipment was held responsible for the loss of 4 aircraft on one flight from Pearce, Western Australia. (See Hall, A Saga of Achievement, p77)
© Ian O'Toole, 2009. Page created: 28/04/03 Last updated: 3/12/2009