Early Electronic Television
We are trading our spare RCA TRK-5 for a rare DuMont field sequential industrial monitor. Several years ago we bought a TRK-5 cabinet at an auction. It had a radio in it, and had a part of the back, but otherwise was empty. The top had been modified to remove a wooden piece on the top.
The first problem was the radio. The TRK-5 used chassis RC-429, which has a tuning eye, push-pull output, and a separate power supply. The radio that was in the empty cabinet is single ended, has no eye tube, and has the power supply on the chassis. Finding a RC-429 chassis is impossible, so the next best bet is the RC-351L, which is identical to the RC-429 except that it has the power supply on the chassis. We found a RCA 97K2 console radio on Craigslist, which has the RC-351L. We will have to extend the speaker wires, add a pilot light line (to the bottom of the cabinet), and add the AC power wiring for the TV chassis.
The bezel that came with the 97K2 was in bad shape. Fortunately, another RCA radio came up on Ebay which had a similar bezel, though it didn't have holes for the eye tube or the "electric tuning" indicator. We will be able to take the two silver metal pieces off the 97K2 bezel and put them on the Ebay radio bezel and end up with one that looks proper. We will paint the silver metal pieces, since the TRK-5 radio bezel is all brown. Finally, we may have to buy a set of replica pushbuttons.
The cabinet was also missing the speaker, a 12 inch with a field coil. The speaker in the 98K2 is identical. We had to cut a mouting board out of plywood for the speaker, since it was also missing.
The restored RC-351 chassis with speaker.
We replaced all the paper capacitors and some of the electrolytics. Also, much of the rubber covered wiring was rotted and had to be replaced. We also replaced the speaker wires with longer ones.
This radio has a RCA jack on the back for connection of a phonograph. One of the pushbuttons connects it to the audio amplifier. It can also be used for TV sound from the main chassis. The radio in the TRK-5 has a AC power switch, which activates a socket for the TV chassis power, connected to that pushbutton. The pushbutton on our radio has a section that bypasses a capacitor used to equalize the phono input. This is not needed for the TV audio input, so we used it to operate a AC relay to turn on the power to the TV chassis.
We also restored the bezel. We removed the two shiny metal pieces on either side of the glass and spray painted them brown. We took out the glass, cleaned it, and reinstalled it. We installed new replica pushbuttons and repaired one corner of the bezel by taking piecs off of another bezel. There are still imperfections, but the restored bezel looks OK.
The modified RC-351 radio chassis
The bezel from a RCA 98T radio
The restored bezel
Next, we were missing several pieces for the television set. The cabinet was missing the safety glass, the wooden piece that holds the front of the CRT, and the metal CRT shield that supports the CRT.
To make a new front support piece, we removed the one from our TRK-5 and used it as a jig for our router. We made our piece out of two pieces of medium density material and screwed them together. The rear part is painted grey to match the inside of the cabinet, while the front part is painted brown. A process called "flocking" will be used to make the CRT opening look like it is covered with felt.
The replacement glass was made by purchasing a piece of 1/4 glass the proper size, then masking it and spray painting the unmasked portion.
One of our original safetly glasses. The speckles are inside the glass, so this one needs to be replaced too.
Next, we made a replica of the CRT shield. We didn't attempt to make it look like the original, since that is beyond our metalworking ability.
The original shield. You can see the front support piece also.
The replica shield
The CRT,shield, and new front support piece
The new glass and front support piece