Sensibly equivalent¶ to:
The EL90 is a small audio output beam tetrode valve capable of 4.5 Watts in a single ended configuration. The EL90 design is the classic 6V6 squeezed into the tiny B7G envelope. The small size means that the valve runs very hot.
The adverts show that Brimar made this valve as the 6AQ5, following the American Type designation, but here we see them marking the envelope with the Philips/Mullard code.
Low down on the back is etched 6AQ5A.
The thin glass tube envelope is 18 mm in diameter and excluding the B7G base pins, is 60 mm long.
References: Data-sheet & 1040.
Absolute Maximum Operating Conditions¶
Updated March 04, 2022.