Onto book #4, covering assembly of the CRT, mask, and chassis frame.
I began the process by building a temporary "T" extension (3/4" plywood and 2x4 legs) onto my workbench to provide enough room to work on the assembled set. Most of the projects I tackle in my shop are a good bit smaller than this beast!
First up, I decided to actually test the CRT to make sure it was still electrically good. The CRT carton was pretty well destroyed by moisture, and the tube itself has a nasty cataract extending 3-4 inches in toward the center in a few spots. Assuming the set makes a good picture, a cataract removal or (preferably) a CRT replacement can be pursued later. The supplied tube is an RCA 25VABP22, but the manual refers to a 25VADP22. Comparing datasheets shows the tubes are pretty much identical, with the later VADP having a "Temperature Compensated" (Invar?) shadow mask for improved purity. I seem to remember that most of the 25V-series tubes were fairly interchangeable, with minor differences like black matrix, rare earth, mounting ears, etc.
Firing up the tester, the tube was a bit slow to warm up after sleeping all these years, but after a few minutes warmup the guns balanced perfectly, with emission and life test readings consistent with a NOS tube.
Assembly begins by placing the plastic CRT mask face down on supports (4 blocks of 2x4), and lining the inside of the mask surface (where the edges of the CRT faceplate rest) with aluminum foil tape as an electrostatic drain. The provided roll of 3M foil tape was still perfectly usable after 4 decades in storage. The foil is carefully overlapped in the corners, and folded over to make contact with the CRT mounting hardware.
The CRT is then placed into the mask opening, making sure that the anode contact faces the top edge of the mask.
The CRT clamps and straps are prepared by adding adhesive felt pads (also amazingly viable despite age) and rubber cushions at the points where the clamps bear against the glass. the clamps are carefully drawn down tight in several stages until they bottom against the mask, then the strap screws are tightened to clamp the tube into place.
A long length of bare solid wire and a coil spring are installed as a grounding contact for the outside dag coating, and the degaussing coil is wrapped around the tube in a very carefully specified pattern (to assure even magnetic field over the mask area), and anchored in place with cable ties.
Next up--final chassis assembly and moving toward "First Light"....