Collins Aerospace Museum

233D Transmitter Restoration Project

Power applied to the modulator’s heater circuits. The Grid and Plate connections make a nice "completed" look.
Attached is final look at modulator tubes before chassis was torn down for re-plating. I thought the 51J and R-390 in the background might be interesting.

I have that chassis and the bias and HV rectifier chassis ready to take to Sterling, IL on Tuesday for plating. Estimate is $450 total for all three pieces and will take 6 to 8 weeks. They accept Paypal, so maybe we can get Dick to handle that from an invoice. Expect to get that worked out Tuesday.

Charley sent the parts list to the CARC membership and Al Groff says he has a pair of 872As that he will donate. Phil Legate has a potential replacement choke for the audio power supply.

Mike Hynek has submitted a request for getting 3 phase power to the room. Larry says the IT folks will remove the two skids in the next few days, so that will allow us to move things around and get the room setup. Larry is also looking to fab a rollaround “Power” cart for the big plate transformer and the power contactor. Larry is also looking at the antenna and feedline. Hopefully, the conduit and outside box on the NE corner of the building will give us access.

Major goals are: June 15: apply power to the racks and start bringing up low voltage elements of the transmitter, July 15: Start reassembly of the three chrome chassis, August 15: Conduct tests of complete transmitter, September 15: Conduct on the air tests, make first contact.

Lots of work remains, but things are looking good.


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More Good News !

Jim Stitzinger called this evening and reported that a friend of his is donating the 0.002 mfd @ 10KV Capacitors. In fact he is giving us four of them in case some fail or are also bad. Jim will bring them to Dayton and give me the fellow’s name and address so we can send him a thank-you letter.
I have Al’s pair of 872’s and several lengths of HV insulated wire (Silicone Neoprene rate at 25kV) that I’ll bring over Monday.