Restoring RCA Victor 28T

[stromberg6]

I almost kick myself for passing up a 28T a few years ago. Great job of restoration! It's a thing of beauty again.
I have a Stromberg 320-T that had a bias cell. I replaced it with a cap and a high value resistor, something like 2 megohms or so, and it worked out very well.
I guess Mallory sold many to manufacturers, as I've seen them on schematics as well as in chassis. Grand daddy of DuraCell?
Again, great job on the 28T!
Kevin

[Reece]

Thanks. Yes, Mallory made DuraCell batteries but the DuraCell name was bought and Mallory went out of existence, I think in the seventies. For years before they were "Mallory DuraCells."

[droptop]

Reece,

Thanks for the tips on your cabinet work. I’m going to try your method of veneer application when time allows and will post results. The console I have is extreme deco styling with inlaid aluminum strips across the front that curve down and cross the speaker grill. It has nicely matched walnut veneer on the front and sides with square tapered legs and a nickel plated dial escutcheon. It should be a nice set once finished. Both the veneer and the substrate layer on top are completely gone as though it just fell off. The solid planks that make up the balance of the top are solid which should make for a smooth surface when finished.

The post from Stromberg6 reminded me of an S-C console I had in the shop several years ago and it, too had a bias cell. I looked up my notes on the set and I did try the resistor/capacitor approach but the tone quality wasn’t up to what it should have been. Once the cell was re-stuffed the bass response improved greatly and the hollow “open grid” sound was gone. Many of the sets I’ve encountered using bias cells were mid 30’s farm radios with 2 volt series tubes like 19, 30, 32 and such along with a vibrator power supply running on a 6 volt battery. There were several models of Truetone, Sentinel and Air Castle radios that had them.

Rick

[Reece]

I may go back in there some time and stuff that cell.

I'd love to find one of the several thirties sets that has chrome accents.

On the Firestone I did, not only was the veneer delaminating but the plywood top was, too. The veneer has to have a completely solid and smooth base with no imperfections or they'll telegraph through to the surface. I had to make a new plywood top for mine. If your set has several different planks on top, it's possible the joint between them could cause trouble eventually if not right away. The joint could possibly have glue forced into it and clamped tightly and then the top block-sanded smooth.

[7"estatdef]

I picked up it's old brother (1940) the 18T. Good sounding set. Rf amp and p/p 6K6's in the output. No bias cell it has a 10m resistor to gnd
http://www.flickr.com/photos/42774321@N08/4508825569/
Nice Job!
Terry

[stromberg6]

Nice find! Congrats!
Kevin

[Reece]

Yeah, they're nice radios, sort of mini-consoles with that chassis and hunky speaker. 1940's answer to the tombstone. With just a cursory look at the schematics, they look pretty much the same except for that bias cell. Notes say they went from a 6" speaker in the 18T to the 6x9" in the 28T. Not sure when they first introduced oval speakers but don't recall them earlier than this?

[7"estatdef]

I think this is about the earlier one I've seen with an oval speaker.
Terry