click pictures to enlarge My First Vintage Television Restoration
00 House.jpg (125633 bytes) Last February, while out on my usual estate sale Saturday runs, I stopped at a sale in the western Minneapolis suburb of Minnetonka. I usually go to between five and ten estate sales every Saturday looking for vintage automatic washers.
01 TV-as-found.jpg (51855 bytes) 02 TV-as-found-open.jpg (52975 bytes) Down in the basement, hidden in the corner, was this beautiful 1951 RCA wood consol television set. Needless to say (although many have asked) it’s a black and white set, color TV’s were not introduced until 1954. The cabinet was in very nice shape and everything seemed intact with all of its original knobs. Since I had my camera with me, I was able to shoot a picture of the exact house and spot in the house I found it in.
011-Variac.jpg (64977 bytes) One thing your not suppose to do to an old radio or TV that hasn’t been run for many years is just go and plug the thing in and flip the power switch on. The best thing to do is use a device called a Variac which allows you to slowly bring up the power to a full 120 volts over the course of many hours, sometimes days. You start it out about 20 volts and every few hours up the control dial another 10 volts or so and watch for any adverse reactions (you know, adverse like smoke, fire, explosions, etc) until you reach a full 120 volts, just like normal house voltage.
022-First-Picture.jpg (18417 bytes) But I noticed that this TV was already plugged in, so I assumed that someone else has already tried it out at the sale today, I decided to just let it rip. After warming up a minute the TV came alive with near perfect sound and a very blurry, rolling, out of sync picture. Well that’s a good sign, at least the picture tube worked. I figured it would be a fun new learning experience; I always wanted to know how a TV set worked and now was my chance. I bought the set for $30 and schlepped it home.
books.jpg (140085 bytes) I have restored over fifty vintage washing machines, but TV’s were a completely different animal with more hazards involved like extremely high voltage and dangerously high vacuums inside the glass picture tubes, so I needed to be sure about what I was doing. I searched for a modern book on how to restore old television sets, but like appliances, found nothing that been written on the subject, so I spent the next few weeks reading all the old 1950’s TV repair books I could find. At first, I only understood about one out of every ten words in these highly technical books, but as I read the same thing written by different authors, who told the same story a slightly different way, it all started to make a little more sense.
Schematic.jpg (160072 bytes) I also went downtown to the main library to get a copy of the Sams-Photofact, for my particular TV, which is a document of the wiring/circuit schematic and special servicing information. Unlike washers or other types of major appliances, post-war radio and TV service information was well documented, for each major brand/model, by the Sams Company. Without this very specific circuit information it would have been impossible for me to get very far with this project.
025 Inside TV Cabinet.jpg (71446 bytes) I was eager to begin, so I removed the back and started to study the make-up of my new TV. There are three main parts to a vintage TV, the picture tube, the tuner and the metal chassis. The chassis contains all the tubes, wires, resistors, capacitors, etc. that allow the flow of electrons through the system. In this particular television, the picture tube is supported by brackets directly inside the wood cabinet, with many other TV’s the picture tube is supported and connected directly to the chassis. This means that I was able to remove the chassis without having to remove the picture tube so the chassis would be much lighter and less bulky to move. I unplugged all the wires from the picture tube socket, yoke and speaker, removed the supporting bolts from underneath and pulled out the chassis from the back.
028 ChassisTop.jpg (110584 bytes) Here is the chassis pulled out (post-restoration), although the top section doesn’t look that much different from the pre-restoration version, except it was filthy with dirt and dust and the poisonous selenium rectifiers were still in use (which I promply replaced with safe modern parts). The first thing I did was give it a thorough cleaning, then I took out each vacuum tube sprayed the sockets with electrical contact cleaner. I then tested each of the 23 tubes and almost all of the tubes tested “good”. I still ordered an entire set of new tubes from Antique Electronic Supply in Arizona, although I later found out from more experienced collectors that tubes rarely go bad, so that was probably a waste of money, but its all part of the learning experience.
03 First look under the chassis.jpg (208837 bytes) Working on the top section of the chassis was the easy part. Now comes the hard part of the restoration underneath the chassis, where the electrons travel from the entrance at the wall plug through a major highway system of entangled wires and spaghetti junctions to get to their final destinations. At first look, I was completely intimidated at all this, I thought it would be an impossible task to have to replace so many parts, in such tight-knit locations, but with a little time and lots of patience it really wasn’t so hard.
Capacitors.jpg (48784 bytes)

resistors.jpg (42284 bytes)

 A capacitor is simply an electronic device that fills with up with electricity and when its completely full it spits out the electricity (discharges) into the circuit and then begins to fill up again for the next cycle. A resistor on the other hand is like an electrical water faucet, they simply slow down the flow of electricity, so the higher the resistance rating a resistor has, the slower the electricity moves, so the longer it takes to re-fill up a capacitor after each discharge. In this TV there are 166 resistors and 132 capacitors, each one has its own job to do in the circuit. In vintage TV’s most of the resistors should still be working close to the way they were performing when it was brand new. Unfortunately, the paper and electrolytic capacitors are a completely different story, as they age, whether they are in use or not, many drift away from their original values and some even being to leak electricity. That means of course that ALL of the paper and electrolytic capacitors need to be replaced, as well as the two large can capacitors that are mounted on top of the chassis, for a complete restoration. I knew this from talking to other vintage radio/TV restorers, but I couldn’t find anything written on this subject because vintage TV repair books do not take into account the fact that the sets we are working on are over 50 years old. After some thorough searching on the internet I found a wonderful web site www.antiqueradio.org. Phil, the webmaster, runs a highly creative and well organized site that includes a wonderful article he wrote on replacing all of a radio’s or TV’s capacitors, commonly referred to as “recaping”. I highly recommend this article for anyone considering restoring a vacuum tube radio or television; I learned everything I need to about recaping a television by reading this.
2nd Picture.jpg (20744 bytes) So I started replacing those old capacitors with brand new shiny plastic orange ones, matching the value of the new ones to the old ones as close as possible. I had quite the job ahead of me, 51 out of the 132 capacitors under this chassis were of the paper or electrolytic kind that need replacing. After replacing the first 8 or so caps I decided to check my work to make sure I didn’t make a mistake which could make things worse. So I reinstalled the chassis, switched the TV on and I saw my very first improvement in the picture! After adjusting the vertical hold control I was able to get the picture to stop rolling vertically for the very first time since I had the set. Even though the horizontal hold control didn’t stop the picture from moving horizontally, it was by far improved over the original picture as I could actually see slight movement of a televised scene between those diagonal bars. WOW I thought, that was just too cool!
Tools for Soldering.jpg (60595 bytes) I couldn’t wait to get home the next evening and continue on, after studying the circuit schematic some more, I replaced another 10 or so capacitors specifically in the horizontal synchronization (horizontal hold control) section of the circuit. Replacing these capacitors is not a quick job, you must heat the old solder on both connection points of the cap, remove the old solder while its hot, then undo the old capacitor leads and remove it, clean the socket connections, rewire in the new cap, resolder both ends in and finally double check your work. One thing that made this easier is the fact that modern 21st century parts are somewhat smaller and easier to work with than their 1950’s counterparts. Each one took me an average of 10 to 15 minutes to do it properly. But it was worth it all.
3rd Picture.jpg (21109 bytes) At 11:00pm that same evening, I reinstalled the chassis, flipped the power switch on, held my breath, waited 30 seconds for it to warm up and YES, I CAN SEE AN ACTUAL TV PICTURE! It was a blurry, washed-out picture with a white line down the center, but it was none-the-less a stable, recognizable picture. YAY David Letterman has never looked so good! What a rush, I can’t tell you how wonderful the feeling of excitement and accomplishment was.
4th Picture.jpg (22383 bytes) Continuing on over the next few evenings, I now replaced another 20 capacitors and was 2/3rd’s done. I reinstalled the chassis and received this rather startling good picture, still somewhat out of focus, but better than ever before. Unfortunately, now something weird happened to the sound. The only way I could get good sound was to adjust the fine tuning to the point that the picture was almost non-existent, in other words either I had a relatively good picture and bad sound or vice-versa, just not at the same time. I poured over the circuit diagram and rechecked my work, everything looked fine. I simply reassured myself that hopefully recaping the other 1/3 of the set would magically fix everything.
FocusControl.jpg (87863 bytes) I started to wonder about the rather blurry picture because I had completely finished recaping the focus section of the circuit and I had begin to notice sort of a burning smell coming out of the big focus control in the back of the TV. So, like I would with a washing machine timer, I decided take the focus control apart to investigate further. Check out what happened to the control, a whole part of variable carbon strip had literally burned away. Checking the parts list on the Photofact I see the control is simply a variable 25 million ohm resistor. Resistors are measured in ohms, 0 ohms means absolutely no electrical resistance up to “infinity ohms” which means complete electrical blockage. All resistors are rated somewhere between 0 and infinity ohms. Now I really needed some advice, so I turned to the Antique Radio-Phono news group for help. This newsgroup, like Applianceville is a discussion group, but for pre-1960 Radios, TVs and Phonographs. I posted my message for help and received some wonderful advice, including the following: 

"If the control can't be repaired, you could do this: Make up a 'daisy chain' of five 4.7 million ohm resistors, plus a 1.5 million ohm (for a total of 25meg of resistance), and connect it in place of the old control. You now have a voltage divider with several taps. Find which tap gives you the best focus".
Homemade Focus Control.jpg (90931 bytes) So I did just that, but I used slightly different values than suggested mainly because a local electronic store had lots of 1 and 4 million ohm resistors for sale, so as long as they add up to 25 million ohms total, I would be just fine. I purchased a junction block and cut it down to 7 sections and wired six – 4,000,000-ohm resistors and one 1,000,000-ohm resistor in series for a total of 25,000,000 ohms. Then I could attach the focus control wire in one of seven pre-set positions, 0, 4, 8, 12, 16, 20, 24 or 25 million ohms. I found the best focus was at 16,000,000 ohm setting and that’s where I’ll leave it.
Under Chassis Completed.jpg (282614 bytes) Now that the picture was focusing properly, I knew this because I could make out each and every of the 525 lines displayed on the screen, I could see another defect in the picture. My TV was suffering from a “smeared picture” which simply looks like objects have horizontal shadows protruding from them towards the right. Plus I still had the good sound/picture not matching up issue so I went ahead a finished recaping the set.  Finally, I finished recaping the set as seen here in this picture of what the underneath of the chassis looks like now. Unfortunately I still had my smeared picture and poor sound problems.
Voltage Measurements.jpg (84379 bytes) The schematic lists what the correct operating voltage level should be at over 100 different wire connection points underneath the chassis, so I figured my next step was to take voltage measurements at each and everyone one of these points and if I find a particular reading was way too high or way too low, I would at least know which area of the circuit was causing the smearing and/or sound problem. But in order to take these measurements you need to have the TV turned on and in order for the TV to be turned on the chassis had to be installed in the wood cabinet. With it installed, I can’t safely reach underneath the chassis with the probes of my voltage meter. So turning back to Phil’s antiqueradio.org I found he had restored a similar RCA-TV and had this same measurement probe access problem, but he figured out how connect the chassis from the outside by laying the wood cabinet down on its side, up on the workbench. After creating some extensions for the cables, I was able to run the TV with the chassis outside of the cabinet, it would taken me a long, long time to ever figure out that little procedure. Thanks Phil! Wouldn’t you know it after all that, the measurements were all within 20% of where they should be, many were within 2%-5%, but it was a great learning experience, of course for extra safety I wore goggles, rubber dishwashing gloves and always had rubber soled shoes on.
 

 

 

5th Picture.jpg (35381 bytes)

 So being completely stumped I turned back to the Antique Radio-Phono news group and I received lots of great advice, although many times I didn’t quite understand what people were trying to tell me. Then I received this little tid-bit: 

"you could well have an open video peaking coil. These coils are wound over resistors, so they would still be "in circuit" even with the coil open. This can easily be checked by simply jumpering each one with a SHORT piece of wire or metal object, (read two small screw drivers) while observing the picture for an improvement".

Peaking coil, huh. So I studied the schematic again and found there are five parts that were labeled "Peaking Coil". So I searched them out under the chassis I found out they looked like white cheese balls, covered in wax. Since they were not capacitors or resistors, I had been previously ignoring them. I took a small piece of insulated wire and used the wire to create a temporary bridge so the electricity would jump around the peaking coil as if it wasn’t even there. There were five to test, the first four made no difference what so ever and my heart began to sink. Then I tried the very last one to check and BOINK, the sound suddenly snapped into a perfect, buzz free melody and the picture, why it’s BEAUTIFUL, the smear is was almost completely gone. For the first time I could clearly see and read all text that was printed on the screen and the best sound and the best picture was now showing up at the same time. WOW, my heart was racing with excitement.
So after a bit of more advice from the newsgroup I decided to replace the one bad peaking coil with a combination of two modern parts, even though the TV seems to be working fine without it, I’m sure it has some good reason for being there in the circuit. After soldering in the new parts I reinstalled the chassis and POOF, no more picture. The sound was fine, but suddenly I total lost both Horizontal and Vertical Sync and my beautiful picture was gone! OH NO, I just was about to Old English the cabinet, bring the TV upstairs, declare victory and watch a 1952 episode of The Adventures of Ozzie & Harriet. So I figured those replacement parts were not working the way I thought they should, I went back in and removed them and I reinstalled the jumper wire that had worked so wonderfully before. Powered up the TV and nothing, still no horz or vertical synch what so ever. Doesn’t that just figure I thought, so close to success and now it’s all gone. It took me over a week before I figured out when I was soldering in those last two parts a tiny drop of solder had fallen 2/3rd down the chassis and had landed between a terminal of four wires and the metal chassis ground. The little splatter of solder was causing electrons to bleed out of the sync separator circuit and go directly to ground. The splatter was completely hidden and I didn’t notice it until after I had removed wires and parts from that specific terminal as I was testing every part in the sync circuit trying to figure out what went wrong. As soon as I removed that solder my picture came back beautifully, I removed the jumper, reinstalled the two parts that caused the solder drip in the first place, and the picture has never looked better.
Post Restoration.jpg (38691 bytes) Tada, here is the finished restoration! One Sticky Decision – OK well I’ve been using the TV for a week or so and while I can comfortably watch the picture with the room lights low, deep in my heart I know that there really needs to be one final improvement. The picture tube has had a lot of usage over the years, this makes them weak and they weaker they get the darker and more washed out they become. Hawkeye Picture Tubes down in Iowa specializes in rebuilding vintage television picture tubes. I inquired about having mine rebuilt and I was told that rebuilding a tube like this would make a difference like “between night and day” in brightness and clarity. But the exterior of the tube in my television is metal, the majority of picture tubes are all glass, but mine is a metal/glass combination. Unfortunately their success rate with metal/glass tubes is only 50%. Under normal circumstances 50% is certainly worth a try until I found out what happens to the tubes that are “unsuccessful”, they explode or more accurately implode from the stresses placed on them during the rebuilding process. So here I sit, like I’m on Let’s Make A Deal and Monty Hall has just handed me $250 which I can keep or I can give it back and take what’s behind the curtain that Carol Merril is standing in front of. Either I’m going to get a beautiful new Broyhill Living Room set or Jonny Olson sitting on a 20 foot tall rocking chair dressed in drag as an old lady, rocking away. What a gamble! Decisions, Decisions, I can’t and haven’t decided yet… More to come.