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Here the cavity is shown mounted with the plate tuner connected to the tuning shaft. The shaft passes through a 1/4" bushing in the front panel. I used an insulated coupler, but it isn't necessary to insulate here (I just ran out of regular couplers).

The cathode tuning shaft does not require a panel control, as it only requires adjustment once during initial tuning, or when the tube is changed.

Here one can also see the mounting location of the bias adjustment control, just above the coolant connectors. This control is above the chassis by about 400v, so if you have a poorly insulated one, consider using an insulated mount (like the meter switch).


A second fan is mounted above the cavity, positioned to blow down through the vent holes in the body of the cavity.

The mounting bracket was made from .060 aluminum sheet, bent into a Z, and mounted to the floor with the 2 screws shown. Holes for the fan, cathode tuning shaft and grid feed-through capacitor were cut with chassis punches.