Collins Aerospace Museum

233D Transmitter Restoration Project

Rod wrestles the BC and BD chassis
The Operational Radio Frequency of our 233D was crystal controlled. We can see here four of the radio frequencies that were in use by Western Airlines:
1500.5, 2327.25, 3309.75 and 5033.0 KC (Khz)
Well, I’ve pretty much completed restoration of the BC and BD Chassis. I managed to find another ceramic post so both broken ones are off our plate now.

Only remaining parts needed are the two prong AC plug (it connects a "heater element" inside the Autotune gear box) and the 300 pF @ 3,000 Volts Transmitting Mica capacitor.

For cleaning up the crud I used Oxy-clean in a spray bottle and an old tooth brush. Sometimes I mixed Windex with the stuff along with very hot water to really get the hard stuff clean.

For the gray paint, I initially rubbed it down with comet and then used some automotive wax. Outcome was reasonable but it took a lot of "elbow grease". On the second chassis, I went to Menards and bought some automotive rubbing compound (said it was safe for clear coat finishes). It worked just as good if not better and with less labor.

On some of the metal straps etc. I tried Brasso. It made things pretty, but took lots of time and smelled up the basement. Still looking for a solution of "stuff" I can just let those metal parts soak and then a quick rub down to get shiny metal.

I’ll bring these two chassis back in to the transmitter Monday a.m., I have a key to archives so will look for a TDH manual or anything else remotely similar to a 233D.