Onto the next assembly manual, covering the assembly of the Tuner cluster/Control panel. The manual is divided into 2 sections, and the builder follows the half with or without the remote control option as applicable.
Work starts out as more mechanical assembly. The VHF and UHF tuners come preassembled, and are mounted into a metal subchassis. The tuner drive motor and gearbox get attached, along with numerous terminal strips and a large oil filled capacitor (4 uF, 370V) used for reversing the tuner drive motor. The supplied capacitor was a Sprague "Chlorinol" capacitor, which was a trademark for polychlorinated biphenyl, or PCB.
Although the cap looked pristine with no signs of leakage, I replaced it with a modern non-PCB cap to remove the environmental hazard. The new cap fits the original mounting perfectly and looks original to the set. The original cap is safely stored away for the next hazmat collection day.
All the pots get attached to a bracket, which is then mated to the front subpanel and the tuner chassis, completing the mechanical assembly. Because I am installing the remote option, drive motors get installed onto the back side of the color and tint pots to allow remote operation. The UHF and VHF channel indicator dials are backlighted by incandescent lamps, and driven via a small timing belt drive. The VHF fine tuning is driven with a ballchain drive system. 4 pushbutton switches are installed for power, channel up/down, and UHF/VHF select.
The wiring is almost completely prefabricated harnesses, which are quite long and make for a real pain on the bench. The unit ends up with quite a wad of wiring attached.
The final part of the assembly is the stuffing of a small PC board which they call the "UHF" board, but what it really handles is the switching between UHF and VHF tuners, and driving the appropriate dial backlight for the selected band. The board is connected to the chassis via a 15 pin Molex connector which supports the entire board. While Heath sent a 15 pin Molex connector which I dutifully installed, It wasn't until trying to plug the board in that I discovered that the WRONG GENDER of connector shell was supplied! Luckily, I had a proper connector shell, as well as the pin extraction tool to remove the contacts from the supplied shell, and reinsert them into the proper one. The board survived the desoldering and resoldering just fine, and the tuner cluster was completed in 3 bench sessions totaling around 5 hours.