233D Transmitter Restoration Project
Eagle Eye Rod spotted some suspicious looking wire on the mod bay wiring. After cutting away the lacing, there were two cloth covered wires that had bare and burned wires. Separating the wires let me bring up the low voltage supply and now everything seems to be back to nominal. I had heard some arcing from what I thought was the rear bottom terminal strip in the mod bay, but it turned out to be in the bundle near the top of the cabinet that supplies the Audio driver chassis. The Mod bay has an odd assortment of power sources. Preamp comes from a dedicated supply in the bay, the tone chassis has its own supply (because it has to come up in remote mode when the balance of the transmitter is off.) But the plate voltage for the driver (4 807s) comes from the low voltage supply in the power bay (that also supplies plate and screen voltages for the exciter stage in the RF bay.)
So we can now extend the wires to the exciter and attempt to bring up the stages through the multiplier (807).
Still ways to go but we could have RF in the next couple of weeks.
More research on the Autotunes. Really looks as though the 1942 TCC documentation may answer some of the questions we have since it uses the same 96E series Autotunes.
| November 16, 2016