The 6FQ7 is a medium-mu double triode. The design purpose was for the line and frame oscillators in television receivers. The 6FQ7 has a heater rating of 6.3 Volts at 600 mA making it suitable for parallel heaters or for sets using the 600 mA series standard it also has a controlled warm-up of 11 seconds.
The 8FQ7 heater is designed for 450 mA heater chains. The 12FQ7 is rated at 12.6 Volts and 300 mA.
For a single triode the dissipation is 4 Watts but with both operating the total dissipation for the valve is 5.7 Watts.
The RCA branding.
The twin triode sections.
The face of one anode.
The thin glass tube envelope is 20 mm in diameter, and excluding the B9A base pins is 59 mm tall.
Reference: Data-sheet. Type 6FQ7 was first introduced in 1965.