Westinghouse Model H-181 Television (1949)

This Westinghouse model H-181 television looks older than it is. The TV was made in 1949, but its highboy style cabinet would look right at home with many console radios from the 1920s and 1930s.

I bought this set at a sale to benefit a local charity. I could tell from their photos that it's actually a Philco model 48-1001, repackaged and sold by Westinghouse. This flyer from TV History shows the H-181 along with other 1948-1949 Westinghouse models.

Our first photo shows the cabinet with doors closed. It's weathered and scratched, but should look great after refinishing. Notice the matched veneer on the doors. The decorative trim is fret-sawed and glued around the door's edge. A decorative cross rail and fretwork corner braces add interest to the base.

Next, the console with doors open. All of the original knobs are present, although I had removed them when this shot was taken. The inside shows the cabinet's original color, a medium, slightly reddish mahogany.

The round 10-inch picture tube is mounted behind a gently rounded rectangular mask. Two mahogany strips hold the reverse-painted safety glass.

The top row of controls are for the user: Tuning, Background, Contrast, Volume, and Off-On/Tone. Below them, concealed behind a removable wooden panel, are controls for the technician: Focus, Vertical hold, Horizontal hold, Height, and Vertical linearity.

This television's schematic is shared with the Philco 48-1001: Riders pages 1-17 through 1-22 and 2-81 through 2-86. Thanks to the Early Television foundation for hosting this and other television schematics.

The electronic design is pretty conventional for the time. The H-181 uses "split sound" audio, which you can read about in my RCA 630TS article. Two 5U4G rectifier tubes are used in the low-voltage power supply. One 6AT6 tube is used for DC restoration, a feature that improves rendition of dark areas in high-contrast scenes.

A front view of the chassis shows all of the controls. The turret-style tuner at the left is missing a top cover, but it won't be hard to make a new one. The big ventilated cage in the back holds high voltage components. To its right you can see the big power transformer and smaller audio transformer.

Like many Philco radios of the time, this television uses several "loctal" type tubes. They're the ones with a glass top and a mirror-like inside coating, mounted on an aluminum base. Loctals never caught on with other manufacturers, but Philco used loads of them in the late 1940s and early 1950s. A loctal tube snaps into the socket, making it less likely to become loose, but its thin pins don't connect as well as conventional pins, so you should clean loctal pins very carefully.

The picture tube socket can seen resting on the high voltage cage, attached to the back of the chassis by its cable. The picture tube mounts inside the cabinet, so the chassis has no supports for it.

The rear of the chassis shows a few more adjusters for the technician. The empty socket at lower left is for the speaker cable. To its upper right is the place where someone tore off the original power cord, an easy thing to replace.

The stamp "Model 48-1001" identifies this as a Philco in Westinghouse clothing. Philco radio and TV model numbers of the time showed the year with two leading digits, hence the 48- stands for model year 1948.

Repackaging another manufacturer's chassis was common in television's early days, when some companies wanted to establish a market presence before they had designed their own TVs from scratch. These "re-badged" sets were usually sold in a slightly different cabinet. The most frequently licensed chassis was the RCA 630TS, which appeared under more than a dozen different brand names.

Underneath we see the usual assortment of paper and plastic-coated capacitors, about forty of the small ones and perhaps half a dozen electrolytics held in cans above the chassis. Replacing them will be the most time-consuming restoration procedure.

Disassembly

After this set had waited a few months in the storage room, I needed a break from a long-term project and decided to start on it. The first step is to get the speaker and picture tube out of the cabinet.

The CRT is mounted on a strong steel frame that screws into the cabinet. The front of the frame has a retaining band for the picture tube's face and the back holds the yoke. To remove the CRT and yoke, loosen the three nuts at the front. Be careful not to let the tube drop.

Before removing the CRT and yoke, I took this photo to show where the yoke and ion trap magnet are positioned on the neck. The magnets are directional, so when replacing this part, you want the same side facing forward and the magnet in the same rotational position on the neck. If you badly mis-position an ion trap magnet, you can make the screen completely dark even though the TV is otherwise working perfectly.

Many different types of ion trap magnets were used over the years, with permanent magnets or electromagnets, one magnet or two, and so on. This TV uses a two-coil electromagnet, with the smaller coil in front.

The tube and speaker are out. I wouldn't normally lay a CRT on its side, but as long as the front retaining ring is holding the CRT bell securely, the stress and weight are distributed through the frame, making this reasonably safe. Just don't bump the neck or let its weight rest on the tube base.

Wear safety glasses whenever you handle a picture tube. Implosions are rare, but flying glass can be deadly. Safety first!

Replacing the Picture Tube

Right after I bought this TV, I tested the tube and I could have sworn it was good. I tested it again this time, and it looked as dead as a doornail. The filament did not light up and it showed zero emission on my Sencore CR70 tester. Checking with an ohmmeter showed no continuity between the filament pins, the sign of a dud. No problem, in the storage room I have another 10BP4 that's weak but usable.

Let's get the old CRT out of the frame. Back in the day, repairmen used pads like these to set a picture on the workbench without scratching its face. The pads are cute, but I normally use an old towel, and you can, too.

One screw holds the yoke's padded retaining ring and another holds the ring around the bell of the picture tube.

Now I lift off the frame, with the yoke and ion trap magnet still attached.

Here is the frame (with yoke and ion trap magnet) on my replacement picture tube. Notice how the yoke is not perpendicular with the CRT neck. This is deliberate. The adjustment screws sticking up from the circular yoke frame let you tilt the yoke to center the image on the screen.

Will the Picture Tube Reach?

We're not ready to power up the TV, but I want to see whether it's possible to hook up the yoke and picture tube with the chassis on the workbench. This will be more convenient than installing them in the cabinet and then muscling the chassis in and out each time that I want to test the TV.

Laying the CRT/yoke assembly on its side, I can just reach it with all three cables. The CRT cable plugs onto the tube base, the yoke cable goes into a plug in back of the chassis, and the picture tube anode lead reaches around from the high voltage cage. I can also plug in the speaker, setting it on top of the audio output transformer.

I'll need to take care when everything's plugged in, but this will let me play the TV completely out of the cabinet, a great time-saver.

Replacing the Power Cord,

We previously saw that the power cord had been torn off at its root. Like many others, this television has a safety interlock. The connector shown in this photo is normally riveted into the back cover, plugging into the chassis when the cover is in place.

The original cord is shot. Bending up four little tabs on the connector case lets me remove the innards. Soldering on a new cord and reassembling the case takes only a few minutes.

Cleaning and Testing Tubes and Controls

The next step is routine: cleaning and testing components, starting with tubes. It makes no functional difference whether a tube's envelope is dirty, but I need to make sure that all of its pins and their socket holes are free of dirt and corrosion. Any defective tubes will be replaced, of course.

This is the dirtiest TV that I've ever owned. To show how grubby it is, I cleaned one of the two rectifier tubes (can you guess which one?) and the left side of a little transformer.

The turret-style tuner definitely needs attention. The top of the tuner cage is missing and the mechanism is filthy. The tuner is immovable, a common condition when old lubricant dries and stiffens. Looking back a previous photo, notice how much cleaner the underside of the tuner is.

The grime can be removed with isopropyl alcohol and paper towels. For tight spaces, I use a piece of 3M no-scratch scrubbing pad held in a pliers. In the second photo, I have removed the high voltage cage and started cleaning the left area of the chassis.

Next, I'll clean all of the control potentiometers with DeOxit and follow that up with an electronic lubricant. After that, if no show-stoppers have appeared, I can apply power for the first time.

Stay tuned . . . .

That's as far as I've gotten at this writing in May, 2010. I'll update this article as I make more progress.