Its role in life is a mixer diode. Mixes UHF osc with the incoming
UHF signal to get the TV's IF frequency.
When you turn to UHF the following happens.
The UHF tuner B+ gets turned on.
The VHF RF amp & mixer tubes are turned into 2
more stages of IF amps & the VHF osc is turned off.
73 Zeno
