QBL 5/3500 VHF amplifier
tube socket details
A view of the still unfinished PA. The eccentric teflon tuning devices are adjusted using a 1 : 80 ball drive. Please note that the size of the capacitor stators (mounted to the lecher) have been changed at a later stage.
Tube with teflon chimney and loading capacitor flapper. Note the the horizontal part of this flapper is of such width and height it represents a horizontal transmission line of 50 Ohm.
Decoupling of high voltage input. The vertical brass plate represents the Hv decoupling capacitor
The anode compartment of the PA with neutralisation probe :
Details of the tuning capacitor. The moving part of the capacitor is made of a plate of beryllium-copper, providing good flexibility.