Lorenz RD12Tf pulse transmitter triode

The valve measures 90x75mm overall, plus the handle, and has an 13-pin base.

Known as the "marmalade jar" this triode can produce pulses of up to 50kW with anode modulation, and is usable at wavelengths down to 40cm.

The base is laid out, as in the picture, with heater and cathode connections to the far left and right. The upper and lower sets of three pins are the anode, with the three pins running across the centre being the grid. This layout allows the valve to operate at high frequencies.