Early Electronic Television General Electric HM-225 Chassis Here is the main chassis. It has been modified to remove the 6F8 oscillator/mixer and replace it with a 6J5 oscillator and a 6AC7 mixer. The above photo shows the original oscillator/mixer tube (with a yellow wire to the grid cap). The RF preamplifier, which was mounted inside the cabinet on the side. It has a 5 position switch to change channels, and a 6AC7. The power supply chassis, containing the 400v and 4000v supplies. |