Zenith Model T1816R Television (1955)

People either love or hate the design of this classic 1950s black and white television. I belong to the "love it" camp. With rounded, futuristic lines and cat's-eye shaped knobs on either side of the screen, it reminds me of a robot or space alien.

Made in 1955, this large metal-cased TV was designed to sit on a table or a stand. The cabinet is dark maroon with a contrasting silver bezel and gold accents in the knobs. The Zenith name appears in raised letters at the top of the bezel and there is a small gold metal Zenith logo on the control panel at the top.

It has a sixteen-inch screen and seems to weigh about sixteen tons! I purchased this set for $35 in January, 1998.

Maiden Flight

As found, the TV was in excellent cosmetic condition but the electronics obviously needed work.

As with all vintage electronics, this one was not immediately switched on at full power. Instead, I gradually increased the operating voltage with my variac, watching for any signs of trouble.

Although the screen lit up on the first try, the picture was unwatchable: either a featureless expanse of snow or a maelstrom of zigzagging lines. The speaker emitted nothing but static. After a moment, I discovered that you could tune stations better by rocking and carefully holding the tuning knob slightly off center—a sign of dirty contacts in the tuner switch.

Before going any farther, I sprayed DeOxit electronic cleaner into the tuner and worked it vigorously through its entire range. This treatment usually takes care of any corrosion and built-up dirt on the contacts, allowing the tuner to operate normally.

Conveniently, the tuner is located near the back of the chassis, where you can reach it by simply removing the cabinet back. A long extension connects the tuner to the knobs in front—a design feature that simplifies servicing.

When I powered up the TV again, I was pleased to see that the tuner cleaning had worked. The picture was still a mess of zigazgs, but I could tell that the tuner was zeroing in on each channel, and now some audio came through.

After some adjustment of the vertical and horizontal hold controls, a wobbly picture appeared. It was far too short and there was lots of "foldover" at the top, but a picture is a picture!

The top panel near the rear of the cabinet exposes two additional adjustments—vertical height and linearity. Using a screwdriver, I slowly adjusted these controls to bring the picture to the correct height and eliminate the foldover. The next photo shows the results.

Although watchable, the picture still wasn't ideal. It was too large in both the horizontal and the vertical dimensions, as I could tell by comparing the picture on a modern solid-state set in the same room. The sound was also very buzzy at the point where the picture looked best. To improve the sound, you had to adjust the fine tuning somewhat "off center" of the station, degrading the video quality.

For a maiden flight, however, this was extremely encouraging. The major systems were all basically operational. With luck, I might only have to finish cleaning the controls, replace any paper capacitors, and possibly touch up the alignment.

Electronic Restoration

In the days since buying the TV, I had gotten an original of its Sams Photofact folder, which includes complete schematics and technical data. Following instructions in the folder, I carefully removed this heavy chassis from the cabinet. In case you're wondering, this is done by placing the TV face-down on a soft surface. I used a heavy bath towel laid on the couch to cushion the glass picture tube. After loosening the mounting screws, you then draw the cabinet upward and away from the chassis. The entire faceplate, including knobs, remains in place.

Before making any replacements, I cleaned the entire chassis and cabinet inside and out. Next, I tested all of the tubes. Only two of them, the 5BK7 RF amplifier and the 6AU8 vertical multiplier, were weak enough to require replacement.

On the whole, this looked like a pretty high-quality television. Of the radio's 74 capacitors, only 14 were the unreliable paper type. The rest were either electrolytics or reliable ceramic units.

Like many tube electronics of the early 1950s, this set used selenium rectifiers in the power supply, in place of a rectifier tube. I replaced the notoriously unreliable selenium units with modern silicon diodes. The originals were disconnected but left in place for aesthetic reasons.

"Recapping" (replacing old capacitors) took a couple of evenings and involved no special difficulties. Compared to my cramped 1957 RCA 14-S-7070G television, this one has a fairly roomy chassis.

The following photo shows the chassis after installing fresh capacitors.

The next photo shows the chassis from the rear. Notice the pair of selenium rectifiers. They are the dark orange finned rectangular objects near the right bottom.

You should always replace selenium rectifiers in old equipment. They are not reliable and when they fail, they can give off an awful odor and even create a fire. The selenium unit can be replaced with a modern silicon diode (type 1N4007) that costs about $1.00. After the above photo was taken, I mounted the new diodes right above the old selenium units, leaving the original recitifers in place (but disconnected) for appearance's sake.

Then I installed the new tubes and tweaked the vertical height and linearity. The picture looked great, with good sharpness and contrast. The picture was slightly off kilter, however. I remedied this condition by carefully manipulating adjustment collars on the neck of the picture tube.

Caution: the chassis of a tube television under power contains very high voltage that can give a fatal shock. Don't ever stick your fingers in there unless you know exactly what you're doing. I am used to working around tube gear, but I still don't believe in taking chances. For this job, I made two temporary tools from long dowels with small non-conductive claws on the ends. The claws were the right size to grip small ears on the adjustment collars. Using these tools, I could safely reach into the chassis and rotate the collars without risking a shock.

There is only one more minor problem that I'd like to remedy. The sound is slightly buzzy when the tuning is centered at the point of best picture. Adjusting the TV's special "buzz control" alleviated the problem, but I suspect that a few more tweaks might improve the sound.

Meanwhile, this TV is very watchable. My wife and I have lately been using it in our bedroom. Our "real" television in that room is a modern color set connected to a hi-fi sound system. Some times we'll turn on both TVs to watch a favorite show. This old Zenith has a slightly bigger screen and frequently it is the one that we prefer to watch.

It's amazing how little you miss color when watching a good-quality black and white set. It also seems less subject to "ghosts" than the newer TV. Perhaps the modern solid-state set is a little too sensitive for its own good!