Hugo Holden's RCA 621 Cabinet Restoration
I've turned my attention to the cabinet now. As you know the CRT mask had been modified in the past and reamed out to a larger size. Perhaps the economy version of a bigger screen TV! The curio here is that whoever enlarged the mask did it in a very professional manner, on a router I think and the horizontally asymmetrical ovoid they created is in perfect symmetry on the left right or vertical axis. They enlarged the upper part more than the lower to give a "theatre like" frame to the CRT face, see the photo.
The edges were close at the corners to the original shape. Therefore I decided to preserve the original wood, as much as possible, and to cut out the "Abnormal Shape" and replace it with fresh timber, again Tasmanian oak.
I can later cut it out and shape it to match the original mask, and re-varnish it and the joins in the timber should not be visible. I've attached the first three photos of this restoration, more to follow.
I've marked out the mask to cut it out to the original size and to make the mitre on the edges to get it as close to the original as possible. I had to wait a few days for the glue to harden. I'm hoping when its rubbed down and re stained the dark colour that it will not be noticeable that it has been repaired, we shall see.
The work on the mask continues. I've attached some photos.
The rear of the mask was easy to shape to fit the CRT face, as its a spherical section so I made a simple tool to hand shape it. The tricky part is the bevel around the cut-out on the front. It was not until I had stained it that the imperfections of its shape were visible, so after this first coat of stain I was able to re-shape it to get a good result. It's waiting to be re-stained in that area, rubbed and lacquered now. I was right about the dark stain, once it was done it conceals the fact that replacement wood has been glued in. I don't think the person who cut that mask out had any idea how long it would take to fix it! It might have been easier to build a replica mask, but I think where possible its good to preserve the original parts, where they are salvageable, for a good result.
The fact that the wood has been replaced is now not noticeable from the front of the mask/bezel. The stain is "Black Japan" and 4 coats of rubbed lacquer, phew tough job that one!
The 621TS is just about finished, see the cabinet
The set is all finished. I also tried the military 7DP4
substitution tube which also produces an excellent picture which is
every bit as good, if not a little brighter, than the nos 7DP4.