The Mullard M8099 is a special quality version of the original 6AQ4 and was made for critical applications. The valve is a miniature single triode for use as a grounded grid amplifier, and thus at high frequency. The CV4070 identification is present on the reverse of the envelope.
This type of valve was designed for RF applications at VHF up to a maximum frequency of 250 MHz. These would include radio, television and radar. The equivalent noise resistance was given as 400 Ω.
The older Mullard logo. Within can be glimpsed the grid winding above the double lower mica. Vibration resistance was found to be possible by simply doubling up on the mica discs.
The interior view. Note the lettering on the right has the UK Government up arrow.
Thanks to Jason Gallaway for sending the images.
The thin glass tube envelope is 17 mm in diameter and, excluding the B7G base pins, is 46 mm tall.
