The 6BQ7A is an all glass miniature VHF double triode used for RF amplification, or frequency multiplication. In the latter case the valve is operated as a non-linear (Class C) amplifier. This causes harmonics of the signal frequency to appear in the anode current. The anode tuned circuit is then chosen to resonate at one of the harmonics, usually the second or third.
The GE logo and the twin triode sections. The copper grid supports are clearly seen.
A closer view of the triode sections. The green lettering is an overprint and on the glass is etched the original lettering and Made in USA.
The thin glass tube envelope is 20 mm in diameter and excluding the B9A base pins the valve is 49 mm long.
References: Data-sheet & 1040. Type 6BQ7A was first introduced in 1954. See also1954 adverts.
