I'm looking for how-to and general theory resources for the vintage restoration beginner. I want to start my first restoration project on a 50's admiral TV/Radio. I've been collecting TV's and Radios for for a while now and would like to take the next step. I've got a $35 Admiral that would be perfect for this. I'm just not sure where to start. Any help would be appreciated.

Thanks
Chris

Well, AudioKarma is a good place to start! Welcome aboard.

You say you've been collecting TV's and radios for a while - have you done much electronic work? Have you repaired or rebuilt any radios? Do you know how to solder? Can you read a schematic? TV's are very complicated devices, and it's best not to just dive in and make a TV rebuild be your first restoration project, it might be more frustrating than you're up for yet.

I would suggest starting by recapping a radio, preferably a small All American Five type radio set. That'll get you used to working in this sort of a device. But, assuming you know what you're up against, press on.

Basically, TV restoration is similar to radio restoration - start by finding a schematic if possible. Here's a good way to find it - look for the chassis number of your television (not the model of the entire set, but the model number of the chassis. It should be printed on the back of the chassis somewhere). Then, punch that number into www.samswebsite.com. That'll give you the Sam's Photofact number that applies to your set. Then, you can go to your local library, the main branch, and ask at the reference desk for Sam's Photofact #xxx-x. Hopefully, they have it, a lot of libraries do. Mine does. Although one person posted that their local library threw them all away years ago. Then, you can photocopy the schematic and information. The Sam's is nice to have, since it has pictures and diagrams and instructions on how to take the set apart and adjust it. Sometimes it's not immediately obvious how to remove the tuner, for instance.

Once you've gotten the schematic, and taken the chassis out of the television, put it up on the bench and clean it up, so you can see what you're looking at. With most tube type black and white televsisions, you're going to have to replace all the paper capacitors - this is just like recapping a radio. Only bigger, and much more complicated. Electrolytics are pretty important too, although it can sometimes be tough to find replacements, since TV's generally need 450volt rated filters. In TV's, it's even more important to do all work as neatly as possible, since there's a lot more stuff in there. I hope I don't have to mention to watch out for high voltage. The picture tube anode cap is several thousand volts, and B+ is in the hundreds. They're much deadlier than radios!

But, before you pick up a screwdriver, tell us something about yourself, what you've done before, and what you're not sure about. I'm more than happy to explain whatever you want, but I don't want to sit here for half an hour typing about basic capacitors when it's all stuff you already know. Also, a picture of the TV you're talking about, and other info, like the model number, and a good picture of the inside will help me be able to explain what does what. (as it applies to your television).

But welcome to the group! We're always glad to meet new TV collectors. There's only what, like three dozen of us wordwide...

-Ian

There's only what, like three dozen of us wordwide...

-Ian

Ha ha, are we that lonely? Yikes. I was the one who posted about the Sams Photofacts being thrown away. Hopefully that isn't the norm with all libraries. I will say this site has some really great people on it who have done everything to help me out. I'm a bit interested in how this thread goes since I have my first vintage set in the garage.

A couple of good books imho

Television and Radio Repairing(2nd edition) by John Markus (good basic text)
Elements of Television Servicing(2nd edition) by Marcus and Gendler (more advanced repair)

Ha ha, are we that lonely? Yikes.
Sometimes it really seems that way... :)

I was the one who posted about the Sams Photofacts being thrown away. Hopefully that isn't the norm with all libraries.
I hope not, I know my library has the whole set, starting somewhere at #100 or so - they didn't get them in the very beginning, so early numbers they don't have, but they have everything else. They're in big bound volumes, but with folder pockets for the TV photofacts. The copier also does 11x17, so it's real easy to make copies there.


I'm a bit interested in how this thread goes since I have my first vintage set in the garage.

Yeah, I should probably come up with a "TV 101" or something... If I get the time, I can take some pictures or write up something better. But a few basic things for beginners:

Start simple. TV's are complicated - if possible start with a radio or something. You need to be pretty good at soldering.

Be careful. TV's can be dangerous. Radios too. Especially "hot chassis" sets. Learn how to properly discharge a picture tube. That thing can store a nasty jolt long after poweroff.

Take notes, go slowly. Document everything you do that you might forget - if you have to remove several parts to replace a capacitor, make notes as to what went where, make a diagram, take a digital photo, whatever. Just in case.

Keep a notebook, and write down each capacitor as you replace it, or check off the capacitors in the copy of the Photofact. This will help you be sure you got them all. Capacitors are nocturnal creatures, and sometimes like to hide in warm, dark places, like inside high voltage cages and tuner housings.

Double check your work - before you plug it in. It's easy to make a mistake, miswire something, etc. If you are up really late working on something and you're getting tired and start making stupid mistakes, go to bed. You'll just drive yourself nuts.

Don't rely on what's installed in your set. Repairs made in the past might not have been right, component values might not be correct. Look for evidence that parts were replaced in the past. See next rule.

Don't rely on the schematic. They're not always right. Sometimes there were incremental versions, production changes, slight differences in chassis, etc. See previous rule.

When in doubt, repair it the way it was (provided the work looked factory), but take note of it, so that later on, if you're having problems with that section, you can go back and try the way the schematic had it.

If the work looks crummy, or if it seems obvious that a part was replaced that was just the wrong value, then use what the schematic has. Take note of this, and the original value the part was, so that you can put it back if it doesn't work.

If you have to make any part substitutions, make note of it. It's perfectly OK in most situations to replace a .047 with a .05, and the like, since the original parts were not too tight on spec. But write down that you did that, because later, when you're looking for something, you want assurance that you're looking at the right circuit, and if you see .047 on the schematic, while looking at a .05, you might forget that you made the sub.

Capacitors are very important. Buy plenty. It's by far cheaper to order them online than it is to buy them one at a time locally. Check out justradios.com. TV's often need 1600v rated capacitors in places, and you can get those at AES - tubesandmore.com. Always buy a few more than you need of each value - either get a kit of common values from a supplier, or just round up to the next 10 or so when ordering. That way, after you get your nice TV running, and you find something else that's cool, you don't have to run out and buy caps before you can do anything with it.

Resistors are cheap. Buy plenty. A kit of common values can be had cheaply from futurlec.com. They've got all kinds of useful parts too. Another good source is jameco.com. You want 1/2 watt resistors for most things in TV's and radios. You don't need to replace all the resistors like you do with capacitors, and you can probably get away with the kit of 1/2 watt resistors that Radio Shack sells. The old resistors are somewhat reliable, and tend to be OK, but check any that you have suspicion about, or that you have to half-unsolder for something else. Old resistors tend drift upward in value, especially if they're exposed to heat, moisture, or were greater than 1meg to begin with. The new ones look a bit different, but they're electrically interchangeable.

Basic tools you need:

Screwdrivers - flat, philips, assorted sizes

Nutdrivers - 1/4", 5/16", 3/8" and 7/16" are the most common (most common being 1/4"). An adjustable wrench is nice to have too.

needle noze pliers - get a little pair of these too.

wire cutters, again, a little pair of these is handy to have too

regular pliers

soldering iron - 30 watt pencil iron for most things is good, and a 100 watt
gun for the occasional electrolytic capacitor-to-chassis job.

digital or analog multimeter


Supplies:

Assorted bits of wire - a roll of 20 gauge solid core insulated wire is indispensable, the insulation can also be stripped off and slid onto capacitor legs to prevent shorts.

Solder - get regular 60/40 lead/tin solder with rosin core. Don't use plumber's acid core solder and don't use lead free solder. The acid core eats electronics, and the lead free solder doesn't actually work.


Test gear that's handy:

A dim bulb tester. This is just a scrap of wood with a power socket and a light bulb socket mounted on it. The light bulb is put in series with the power socket. This is handy to help as a "first test" to see if the set might have a short

An isolation transformer. Finding one of these is hard for a tube TV. Arcade machines use isolation transformers for the monitor - one of these may just be beefy enough to handle the power draw of a tube TV, but likely not. I use an old medical isolation transformer I found in a scrap pile. This isn't necessary, but it's a nice safety precaution when working on hot chassis TV's. A Variac is NOT an isolation transformer, and does not provide any isolation from the mains.

A variac. I don't have one of these, but I hear they're neat. Not necessary - the dim bulb tester works the same for most purposes. But, like I said, they're neat.

I'll write more, and organize things better when I get time.

-Ian

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300128931327

I strongly recommend this book.

Ha ha, are we that lonely? Yikes. I was the one who posted about the Sams Photofacts being thrown away. Hopefully that isn't the norm with all libraries. I will say this site has some really great people on it who have done everything to help me out. I'm a bit interested in how this thread goes since I have my first vintage set in the garage.our libarary threw out some nice books , including one called " How to use test probes " It was a Rider pulication from 1954 , and was real handy for various TV and radio service jobs . One day I went in the to get it , and it was gone , later on I asked about it , and I found out it was dicarded .:thumbsdn:
So I was on Ebay and found one in New York , and now I have my own copy .
There are quite a few old TV books on ebay , and they are really handy to have . The great thing with a vintage book is it deals just with tubes and equipment from that particular era . I would highly recommend any of the Rider publications , and for basic do it yourself you there were a few TV books done by Art Margolis in 1962 and 64 , I got these years ago and they were a great beginners book with lots of test pattern pics and everything in plain english .

Welcome to our TV world here on AK .

There's only what, like three dozen of us wordwide.
Many more than that. If you attend the annual convention at the Early Television Convention in Ohio, you can meet collectors from around the United States and as far away as Europe.

http://www.earlytelevision.org/

I agree that a TV is not the ideal first project. Starting with a simple 5-tube radio would be a better introduction -- you can make your beginner's mistakes on that.

The best TV repair books are out of print, but if you want to cut your teeth by restoring a simple radio, you could get a beginning radio book such as "Antique Radio Restoration Guide," by Johnson. A lot of the basic information, such as identifying components, needed tools & test gear, etc., is the same for TVs and radios.

One caveat about reading old repair books: restoring a 50-year old TV is different than what a repairman faced in repairing a 2- or 5-year old TV. After decades, the electrolytic and paper capacitors have deteriorated, so probably all of them need to be replaced. Controls may be corroded or frozen. And so on.

In the old days, a repairman could usually diagnose a problem quickly and cure it by popping in a new tube, replacing a burned resistor, etc. The rest of the TV was still fresh and didn't need any attention.

Nowadays, the situation is reversed. Every 50-year old TV has a multitude of little issues, caused by aging and perhaps decades of use, which you need to deal with before it will be safe and reliable to play. That why I call it "restoration" rather than "repair."

It's like finding a 50-year old car in a barn. You can't expect to just top off the gas tank and hop in for a cross-country drive :-)

Phil Nelson
Phil's Old Radios
http://antiqueradio.org/index.html

Thanks for the warm welcome,

My vintage electronics repair experience is pretty limited, I have a basic understanding of electronics, I've done some basics like tube testing, tube socket replacement, chassis removal, and wire replacement. All on radios. I've never really diagnosed anything other than a bad tube or tube socket. I have more experience with solid state microcontroller electronics. I can read schematics and can also solder. I do understand the dangers of HV but still a little nervous about sticking my hand somewhere it doesn't belong.

I have many vintage radios I can use for the learning process and have considered this. I think starting by recapping a radio is good advice. I plan on doing this while gathering info on the TV restoration. I have and have read the Antique Radio Restoration Guide so I'm good to go there.

I own three TV's, a 1952 RCA Lindale model #21T227, a 50-51? Admiral Tele-Bar model #32K146 and an Admiral model #421M16N, this is the one I plan on starting with. This is one that I'm most willing to risk to my lack of experience. I Just bought this one locally for $35 and have not plugged it in yet but I'm going to assume it does not work. All the sets mentioned above have repair needs.

What I lack is the basic knowledge of how the many different TV circuits work, which we all know is key to proper diagnostics. I'm hoping to find this in the soon to be purchased books. I am planning on going to the Early Television Convention this May, I live in Cincinnati so I'm about one and a half hours from the museum.

A lot of the questions I had have been answered in this thread already. Please keep it coming.

Chris

Here's some pic's of the project TV, note the mouse nest near the lower left of the picture tube. It an Admiral Model #421M16N.

....

I always want to know the status of the crt before i invest substantial time or effort....Do you have access to a crt tester?

I always want to know the status of the crt before i invest substantial time or effort....Do you have access to a crt tester?

No i don't, although I've been considering buying a Picture Tube (CRT) Restorer/Analyzer/ Rejuvenator. Is there any other way to test the crt's?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=300128931327

I strongly recommend this book.

just bought a copy on Ebay

Here's some pic's of the project TV, note the mouse nest near the lower left of the picture tube. It an Admiral Model #421M16N.Nice set , the mouse also must have liked it .:yes:
It reminds me of a Crosley I got a few years ago . My advice would be if you are going to go right into working of tv's , do each lead for the capacitors one at a time , and then you will know where the other end is supposed to be connected because the old cap will still be attached . I still use this method , it saves lots of time retracing wires .

kbmuri , Im glad you posted "How to Troubleshoot a TV Receiver" on ebay I was looking for a copy of it myself . I searched it a while back and no one had it .
I also got one now :banana:

No i don't, although I've been considering buying a Picture Tube (CRT) Restorer/Analyzer/ Rejuvenator. Is there any other way to test the crt's?The Beltron is the best and also does a better job of rejuvenating the CRT , they sell on ebay for 120 bucks ???? if I am correct . But just for general the B&K model 400 is a great unit , it's self contained in a carring case , and does emmision and short tests and also rejuvenates CRT's , the rejuvenation is course compaired to the Beltron .
But the B&K 400 is common and usually sells for $20.00 or less .
This thread was started a few months back , it might be of interest to you .
http://www.audiokarma.org/forums/showthread.php?t=130048

Before you do anything, you need to replace all the paper and electrolytic capacitors. Then you can at least safely turn it on and see what you have to work with. A lot of 50's TVs work fine after replacing the caps, cleaning the tuner and other controls, and making a few minor adjustments. Be prepared to find other problems though.

This is one thing I have learned is very important...if there are any old capacitors still in there it can cause all kinds of hard to track down problems and make it impossible to repair.
I always start with all new capacitors and check the tubes and then troubleshoot any problems which may be due to resistors, etc.

I also highly recommend the photofact. This comes in very handy on sets which use the old color band caps...it helps to confirm which cap is what value. Also you will need the voltage test readings to help you if you have any problems after the capacitors are replaced.

Also just looking at different photofact schematics and tracing how the signal flows from one part of the set to the next is very helpful in understanding it. The schematics are always layed out so you can see how the signal starts from the antenna terminals and flows through the tuner, to the IF, where the sync signals come off, etc. Also you can see things like how a vertical output tube or audio detector can rely on boost voltage from the horizontal output section, or how an audio output tube can act as a voltage divider and supply plate supply voltage to the IF tubes...things that might not be immediately obvious but can help with tough troubleshooting problems.

That set you have for your first TV project actually looks like it will be a very good set to start on. It's a 50's set with a large all glass tube and a big metal chassis. The all glass tube is nice, because those have much better odds of still having their vacuum. The large metal chassis is a big plus, because it will be pretty easy to work on, comparitively, to some other sets. It will be cramped in places, but still, not too bad to work on. This set uses a power transformer, which is another nice thing - hot chassis sets are scary.

Now, I'm still reccomending you start with a radio first. But that should take a day or two. Then you can start on the TV.

First thing, you need to pull the chassis out of the set. To do this, remove the knobs on the front. If this set has a flip down door (doesn't appear to, but might), check in there for knobs too. They should just pull off, but check for setscrews first. Then, from inside, disconnect the yoke plug. The yoke is the big coil on the back of the picture tube - it deflects the electron beam magnetically to scan across the face of the tube. It's attached to the chassis with four wires, that should terminate in a plug. Some of the later, cheaper sets omitted this plug, requiring that you remove the yoke to take out the chassis. This one seems to have a plug. Disconnect the connector at the back of the picture tube. Do this CAREFULLY. The base of the picture tube might not be still attached to the glass, the glue dries out over time. Hold onto the base with one hand and gently pull the connector off with the other. Disconnect the high voltage lead from the side of the tube. Since this set has sat unplugged for decades, there's no danger. But to be on the safe side, get in the habit of discharging the tube any time you disconnect this wire. It's the big scary one that attaches to the right side of the tube with a suction cup. High voltage can be stored here because the tube acts like a big capacitor.

To discharge a picture tube, you should make a discharge tool. Get an inexpensive large flathead screwdriver with a long shaft and a fairly narrow driver end, and a good plastic handle. Then, take a length of lamp cord and bare both conductors on one end. You'll want to expose a few inches of copper. Twist the wires together and wrap them around the lower part of the screwdriver shaft tightly, making sure to get good electrical connection. You want to finish your wrap at the bottom of the shaft with a turn or two of the still insulated lamp cord. Wrap the shaft of the screwdriver in electrical tape, from top to bottom, leaving two inches or so on the driver end bare. Use a couple coats of tape. On the other end of the lamp cord, bare a short amount of wire (both conductors), and twist them togehter.

Now, a lot of people prefer to use a resistor to discharge tubes, and they're probably right. I never did, simply because I didn't know any better. Also, it's hard to find a suitable resistor, from what I hear. I still do it without a resistor, but I'm sure others will chime in with a proper value and type to use. I think a large power resistor of one meg or larger is what's good to use. I don't use the resistor... If you want to use a resistor, connect it here, to the end of the lamp cord.

Connect the other end of the lamp cord (or the other end of the resistor, if you used one) to a large alligator clip. Be sure to make good connections (solder, if possible). And wrap any exposed metal in plenty of tape.

To use the discharge tool, clip the alligator clip onto the metal chassis of the TV, and carefully slide the screwdriver under the suction cup until you feel the metal spring clip in the center. If you didn't use a resistor, you'll hear a nice loud SNAP if there was any high voltage stored. Without it, I don't think you will. Do this again, just to be sure.

To disconnect the anode lead, once it's discharged, squeeze the suction cup together at the top, and rock it free. You might need to peel it up to see the connection, but it's two little bits of springy metal that stick down into a hole in the tube, and clip in (kinda like the top of a christmas ornament). You just need to gently press these clips together and work them out.

Disconnect the speaker, noting the polarity if it doesn't have a convenient connector. (You are making notes here, right?). Check to make sure there isn't anything else connected, some cabinets have a built in antenna, etc. Under the wooden shelf that the chassis is resting on, there will be several bolts (probably 4). Remove these.

Now, you should be able to slide the chassis out the back of the set. Do it slowly, to be sure that nothing else is still connected, and that the mice haven't started to regroup. You're stealing their home, after all. Careful, it's heavier than it looks most of the time.

Once you've got the chassis out, you can clean the inside of the cabinet. Check for signs of leaked tar or wax under where the chassis was, and any signs of burning in the past.

Take the chassis and start cleaning it. Make a chart of all the tubes, and remove them. Watch out for the rectifier tube in the back, it's often held in with a springy clip that will constrict on the base when you pull it out. Hold this spring down to pull the tube out. Vacuum all the crud out of tube sockets, corners, etc, and clean everything real good. Careful not to damage coils, or get water into them. Don't polish the tubes with Windex. I know it'll make them shiny, but it will also take the numbers off. I've found that the best way to clean them is to run them under warm water for a bit, and gently wipe them on a cloth, like an old sock. You'll want to note the tube number first, in case it does wipe off. Depending on the tube manufacturer, the other non-number markings may come off. (GE tubes particularly). The number on GE tubes is put on with another kind of paint, and doesn't rub off as easily. If the number comes off, feel free to scrub and polish the tube all you want, then write the number back on with a sharpie. Avoid cleaning tubes unless it really needs it.

If you have a tube tester, test the tubes. Note any that are weak - but remember that in a TV, a weak tube might not actually cause problems. It's best to try the first test with the original tubes, provided that they're not broken, open, or totally dead. But put the tubes away for now, you need to turn your attention to the rest of the innerworkings.

Turn the chassis on it's side and look carefully for signs of damage, mouse-eating, burnt wires, missing parts, or Jimmy Hoffa. Carefully clean away any crud you find, compressed air and a clean paintbrush work well, and you can vacuum provided you're careful not to disturb anything. Figure out a way to get the chassis to stay up on it's side. Metal L brackets bolted to the original holes, clamping it to your workbench, whatever. You just don't want it to fall over when you're working on it.

Look at all those wax capacitors! You need to replace them all. Before you start, take digital pictures of the underside of the chassis. Close up ones too. You want to have a reference point just in case. Using the schematic as a guide, start replacing capacitors. Go slowly, take notes, and don't be sloppy. Clipping the old capacitor leads, bending the ends into hooks, and soldering new ones onto that is sloppy. You'll actually want to, wherever possible, actually desolder the leads of the old capacitor, properly attach the new one to the terminal strip, and resolder it. Clipping and tacking works, and you might get away with it in a radio, but it looks sloppy, creates more connections, is more prone to shorting, and ultimately makes the new capacitor rely on a 50 year old solder connection that may not have been that great, and an old oxidized capacitor lead.

To desolder, I like to use a desoldering pump. The blue one from Rat Shack (about 8 bucks) works well. Heat the connection with the iron, and flow new solder into it. This gets the solder melted and supplies it with fresh flux. Then, put the desoldering pump next to it and press the button. This takes practice - another reason to start on a small radio. You might have to do it a couple times, and even then you won't get everything perfectly clear. But once you can see the way the old capacitor lead was folded around, you can use your little needle nose pliers to gently unfold it, and straighten it enough to remove. Once you've gotten the old capacitor lead out of the terminal strip, clean the terminal up with the desoldering pump. Install the new capacitor like the old one was, use 'spaghetti tubing' or stripped off solid core wire insulation to insulate the leads if necessary, since the new one is smaller than the old one, there will be a large area of exposed wire - more prone to shorting in some areas. Try to only remove one cap at a time, but many times you'll need to take off three or four at a time in a TV, since there will be a couple tight together, or on the same lug of a terminal strip. This is another reason to start simple. But take notes, and you'll get it back together. Also, don't push or pull too much on a terminal strip, tube socket, whatever. Terminal strips are just bits of phenolic with metal tabs, and it's easy to break them if you're not careful. Be extra careful around coils - the open type are just wax dipped cardboard with wire, and the soldering iron can melt them. You might have to tack onto old leads here if you're not comfortable removing the old lead from the original tab. When resoldering the connection, always heat the terminal, not the solder - and flow the solder in, making sure it makes good electrical connection. Don't wiggle anything as the solder cools, this will create a cold solder joint. Wiggleing as the joint cools is, however, a great way to create a bad solder joint to make it easier to remove the old capacitor, however. A good connection will be shiny. Once again, you MUST use rosin core, lead/tin solder. Lead free solder is unsuitable for electronics, and acid core plumber's solder is a bad idea, for obvious reasons.

The electrolytics are another story. Here you have to get creative. The electrolytics are the big cans on the top of the chassis. New electrolytics are smaller, and look much different. Common practice is to disconnect the original electroltyics, and connect new ones under the chassis. You might have to install a terminal strip to mount them on. Make sure the electrolytics are installed the proper direction! They have polarity. The cans are multi-section electroltyics. That means that the can's outer casing (or outer terminal) is negative, and the inner pins are the positive sides of the capacitors in the can. The side of the can will list symbols (circle, triangle, etc) that correspond to the symbols stamped on the bottom of the can near the pins. The schematic will help a lot here.

Remember, replace only the paper capacitors, and the electrolytics. Leave ceramic disc capacitors and mica capacitors alone. See http://www.antiqueradio.org/recap.htm for more information on capacitors.

Any time you have a terminal strip cleared out and have a resistor that's only connected on one end, check it with your meter. If it's out of spec (+/- 10% of the printed value) replace it. You can't really check resistors that are in circuit at both ends, because the rest of the stuff in the set will interfere with your readings. But don't go unsoldering every resistor - just do the ones that you run accross. Pay special attention to any resistors that are supposed to be 1meg or higher. They drift the most. Use proper rated replacement resistors. Most common resistors are 1/2 watt. The big suckers vary - check the schematic.

Have fun, and if you have any questions, don't hesitate to ask!

-Ian

No i don't, although I've been considering buying a Picture Tube (CRT) Restorer/Analyzer/ Rejuvenator. Is there any other way to test the crt's?

Not really...You may be able to find another akr in the vicinity that has one that will let you borrow or test your crts for you....That is how I did it before I had one of my own.

I've read instructions for testing a crt with a multimeter (or maybe VTVM) but it was kinda complicated.

I'd agree that this Admiral would be a great one to start with. Straightforward.

This set probably uses a lot of black beauty caps. Often called bumble bees-they are marked with colored stripes, similiar to resistors, instead of having the values printed on them. For the longest time I mistook them for big resistors, and I don't think I'm the only one! Helpful to have the Sams when replacing them since they're not always easy to decode. You should save the old bb caps-people have been known to pay good money for them on ebay!

We have never had any problems with using the old capacitor leads to attach the new one to. I always file the end of the old lead so a good connection is made, and add heat shrink tubing or spaghetti to the lead if needed for insulation. This method avoids the heat/physical stress on old terminal strips, tube sockets or coils that can be caused by completely desoldering all the old leads.

Also always make sure you put a fuse in the AC power circuit if there is not one already. You can put an in-line fuse holder or mount a fuse clip under the chassis.
If a short occurs in an un-fused set, serious damage to the set can occur...the house circuit breaker will likely not trip on the overload and the current can flow until the 5U4 tube literally melts or the power transformer is charred. A 3 to 4 amp fuse is probably good for an old TV.

I try to keep the leads dressed as original, if possible.

Another tool that's super useful when you have the tricky problems, is the oscilloscope. I find it right behind the multimeter as the most useful thing - it'll help you find problems - fast - once you know how to use it (not hard!).

For TV circuit theory and repair, look for a book written in the late 40's or early 50's - they were written for radio folks looking to get into TV, so they were simple and covered circuits in detail. Admirals were pretty simple and straightforward sets.

Another thing - be careful with the CRT. They break easy and they're pretty nasty when they do. NEVER hold one by the neck, or place it face down on a hard surface. I like to have an old bath towel folded up as a surface, and put it in a safe place. Not only does glass go everywhere when they break, but they're harder and harder to find these days.

And remember, a TV isn't magic! And the set you had worked at one time - so, if something's not going, sleep on it, ask questions, etc. You'll get it eventually.

I like to get the sweep going then the picture and tuner circuits. Often, you need the sweep for B+ boost anyway. Once you've confirmed the CRT 'lights' don't worry about yoke and ion trap adjustments too much, just enough to get a raster. You'll have to fine tune them in the set anyway.

Don't turn screws on transformers and coils unless you know what they do and you're 100% sure that's the right thing. Re aligning a TV set's tuner and IF is a royal pain and requires a bit of equipment...

Tubes 101: Plate higher voltage than cathode, grid lower voltage than cathode, screen almost voltage of plate, supressor same as the cathode. Blue glow ok, purple glow bad (unless it's an OA2), red plates bad, sparks really bad. Silver = vacuum, white haze = no vacuum.

Oh yeah, and stay out of the HV box while the set's on (and watch for the horizontal output plate cap!)

Another tool that's super useful when you have the tricky problems, is the oscilloscope

I have an oscilloscope, that i have never used. What leads do i need for TV restoration?

Thanks to everyone for the information, it's incredible the amount of information everyone has given me so far.

Retrohacker, your awesome!!! Just what i was looking for. I appreciate the detail. It would be great to see your name on a modern "How to restore you vintage TV" book (Yes that’s a hint):)

I agree with most of what has been said. If you don't start with a few radios first, then this set is a fair "beginner's" TV. The CRT stays in the cabinet so you don't have to lug it around with the chassis. The chassis is big, so you have room to work. It's not a super-early set that can have completely unobtanium parts if you break something.

I photographed a lot of said details on this thread:
http://www.audiokarma.org/forums/showthread.php?t=76517

It's more than a year old, perhaps some of the newcomers haven't seen it.

I also have done a hundred radios and a half-dozen TV sets and have used the clipped-leads-of-the-original-capacitor trick and never had a problem. I've found that the terminal strips can be fragile, the leads are usually wrapped several times and crimped before soldering (which makes it a BEAR to desolder), and you have to put a LOT of heat into them to get the solder off. If you clip the old capacitors out as close to the cap body as possible, sand the remaining leads bright with wet-or-dry fine sandpaper (the kind that doesn't "shed" sand), 200 or 400 grit, you can tack onto them with 100% results. And you keep the heat requirements light, no melting nearby coils or other unobtanium.

I don't like to bend the leads into hooks, but rather leave the original leads straight, bend the new cap's leads into tight spirals, then slide the spirals over the straight original lead. Flow solder into the whole works and you have a tidy joint that comes apart next time with just heat (no more clipping or sanding).

I use a 500K, 2-Watt carbon resistor for discharging CRTs. Same method otherwise (flat-blade screwdriver and electrical tape).

The tube numbers on GE, RCA, etc (American) tubes are sandblast-etched into the glass and won't wash off (even when the painted labels wash off). European tubes, the tube number usually washes off too. Good way to turn a 100-dollar Telefunken or Bugle-Boy ECC83 into a 5-dollar anonymous one. So leave the foreign tubes alone. I windex my US tubes usually, to no complaints. Really helps the motivation to have some sparkling glass to look at.

Most of all, have fun, take your time, post pics, and enjoy the hobby.

Speaking of ctr tester/rejuvenators, will these things work on the smaller tubes like the 7JP4?

The Beltron is the best and also does a better job of rejuvenating the CRT , they sell on ebay for 120 bucks ???? ...

The last 3 or 5 Beltron restorers on eBay sold for around $35-$50.

The consensus around here is that the Beltron is the best. Mine has restored two zero-emission tubes to full strength, removed a strange arcing from the neck of another, and tested and verified the "Good" status of my remaining working sets. Based on how each tube performs vs. what the Beltron tests them at leads me to believe the Beltron's test readings are accurate enough.

I've been told that the Beltron will do 7JP4s and 3KP4s by a very good authority. Another AKer here made an adaptor to fit them, it doesn't originally come with that socket size. He posted the plans, a search of the forum should find it easily.

I've read instructions for testing a crt with a multimeter (or maybe VTVM) but it was kinda complicated.

I'd agree that this Admiral would be a great one to start with. Straightforward.

This set probably uses a lot of black beauty caps. Often called bumble bees-they are marked with colored stripes, similiar to resistors, instead of having the values printed on them. For the longest time I mistook them for big resistors, and I don't think I'm the only one! Helpful to have the Sams when replacing them since they're not always easy to decode. You should save the old bb caps-people have been known to pay good money for them on ebay!

Yes, I was once one of those that thought bumblebee caps were resistors. When I was about 12, I found one of these caps blown apart in a radio. I took the cap to the local parts house and told the older man working there that I needed this resistor. He explained to me that the part was a capacitor and pointed out the foil.

As far as CRT testers, I use a B&K 480 from the '90's. With the right adapters, it will test most CRT's from the late '40's to the present. If you can't find a Beltron, look for a B&K 467, 470, 480, or 490. Try to stay away from anything before the 467. They will check the older tubes OK; but, their rejuvenate function often does more harm than good. My first CRT tester was a B&K 465 and I ruined more tubes (especially the color tubes) than I helped with that model.

I thought i'd give a quick update.

I've started on the Dim Bulb Tester and will be finished tomorrow, i ran out of parts and need to hit the hardware store in the morning. Easy to make and i'll have maybe $10 after i'm done. Can't wait to try it out. I'll post a pic when its done.

I've also started on my radio project, i chose a 5 tube RCA. It's really simple and looks like a good first re-cap radio. I have no caps on hand so again tomorrow i'll have to hit the local Radio Shack in the morning for parts.

I'm hoping to have this done tomorrow also. I may do a couple while i'm waiting on the TV schematics and caps.

I'll keep posting updates

Be careful. TV's can be dangerous. Radios too. Especially "hot chassis" sets. Learn how to properly discharge a picture tube. That thing can store a nasty jolt long after poweroff.


How can i tell if i have a hot chassis? Is it as simple as checking voltage from chassis to ground?

The set that you are starting on has a power transformer and therefore does not have a hot chassis. A set with a hot chassis is one were one side of the power line goes directly to ground.

Steve

As Steve K. said, that set you have has a power transformer - so no hot chassis. But the radio you're starting on (5 tube RCA) is most likely a "hot chassis" set. Let me guess, the five tubes are 35W4, 50C5, 12BE6, 12BA6, 12AV6? In order to save the cost of a power transformer (the single most expensive and heaviest part of a small radio), the radio and tube manufacturers came up with a set of tubes that, when strung in series, equaled roughly the power line voltage - 50+35+12+12+12=121 volts. Close enough to the power line to work well. All the tube heaters draw .15 amps, so in series the voltage drops work out. To generate the B+ the tubes need, they rectified the line voltage with the 35W4, and smoothed it with a couple of electroltyics, yielding something on the order of 150v. It works well, but it also means that the set's "ground" is essentially one side of the power line. And this was in the days before polarized plugs and grounding prongs. You have a 50-50 chance that the chassis will be connected to the "hot" line, so if you were to, say, touch the chassis while leaning on a radiator (grounded), you'd get a nasty shock.

To make matters worse, a lot of the earlier sets (espeically when they were the octal series of tubes - 50L6, 35Z5, etc) had metal screws that connected to the chassis and were exposed on the bottom. In later years, they got creative. The metal chassis was no longer "ground" but connected through a resistor and a capacitor. This works pretty good, and is safe - at least until the cap shorts. In some of the even later sets, the knobs can't even be pulled off the front - the chassis must be pulled out the back, off the knobs. This is because by making it so that the knob can't be pulled off (metal retaining clip inside), the metal shafts can't be exposed, which would potentially be line connected. They didn't care about lost knobs. Only lawsuits.

Now, that doesn't mean these radios are unsafe to use, just be careful and use common sense. And once in the cabinet, the radio will be fine. But when working on it, either use an isolation transformer, or simply be careful to only touch plastic knobs when the radio is plugged in. I always put some knobs (any random junk knob will do, if you're worried about them getting damaged) on the chassis when I'm working on it, regardless of wether it's a hot chassis set or not. It makes it easier to turn the shafts when testing, and of course, on those transformerless sets, it's a safety measure.

And don't be shocked (pun not intended) if you get a tingle from a transformer type TV or radio chassis. There's typically a bypass cap that's connected between the AC line and the chassis to reduce noise. These were originally regular paper type capacitors. When they're bad, they start to leak, and then you get voltage on the chassis. Another reason to replace capacitors.

And you're not going to find the parts you need at Radio Shack. The electrolytics you need are 160 volt rated, and the normal caps you need are at _least_ 200 volt rated. They don't carry stuff like this anymore. You need to go to an electronics store, or order parts online. Justradios.com has a great price on a kit of 240/230 common capacitors (non-electrolytic). It's $70, but the shipping is free, and it's much cheaper in the long run over buying them one at a time. I use these caps and I'm very happy with them. If you get the little yellow ones, be sure to pick up .047's too, they're not in that kit, but you're going to need/want them for five tube sets. They carry electrolytics too.

-Ian

A quick and usually reliable way to tell if a set is "hot" chassis: look at the tube numbers. If they all (or almost all) start with a 6 then it should be okay. (that means all the tube filaments are wired in parallel) In a hot chassis they are wired in series, like Christmas tree lights, and they will not all be the same voltage (don't ask me to explain why!) You can have tubes starting with all sorts of numbers and if they are jumbled up like that you can bet it's hot. The vast majority of 5 tube radios are hot chassis, known as the All-American Five. Most common used 3-12 volt tubes plus a single 35v and a single 50v. Probably what your RCA is. You just need a little extra respect when working on them while plugged in. (Touch the chassis while warming your feet on the baseboard heat, as I did at age 12, and suddenly YOU will be plugged in! This did not kill me :) but it also did not encourage me to do it again!)

Oops! I stepped on you a little, Retro!

One more thing I forgot to mention. On your five tube radio, make sure that the pilot lamp is good (if it uses one). If it burns out, then the rectifier tube will be run too hard, and burn out more quickly. The rectifier tube actually has a tapped filament, so that a pilot lamp can be connected to it without needing a dropping resistor. The way some sets are wired, the plate of the rectifier is connected to the lamp tap as well - this makes the light brighter, but if the light burns out, then the rectifier filament at this tap has to bear the extra load of the B+ current. It'll burn out faster. So replace the pilot lamp if it's burned out, or rewire the set so that this isn't going to happen.

Doesn't apply to all radios. But it applies to many.

-Ian

In some of the even later sets, the knobs can't even be pulled off the front - the chassis must be pulled out the back, off the knobs.

Thats exactly the way this RCA is built, I couldn't get the tuner knob off until i pulled from the chassis side.

Let me guess, the five tubes are 35W4, 50C5, 12BE6, 12BA6, 12AV6?
Yep

No power transformer, the power cord is connected to 35W4 tube socket and then to the on/off volume control.

You just need a little extra respect when working on them while plugged in. (Touch the chassis while warming your feet on the baseboard heat, as I did at age 12, and suddenly YOU will be plugged in!

I'm glad i asked.

There's only what, like three dozen of us wordwide...

'Bout a hundred of us show up at the Early Television Convention every year!

We have never had any problems with using the old capacitor leads to attach the new one to.

Here's a present-day version of an old radio repair kink: http://tinyurl.com/39jzga

Here's a present-day version of an old radio repair link: http://tinyurl.com/39jzga


These are exactly the tight spirals I make. I must have seen an original "quig" sometime in the long-lost past.

Note the comments about "Original Craftsmanship". My point exactly.

Thanks, Dave for the link.

My capacitor kit came in from Just Radios yesterday afternoon, and after a couple of hours my first radio project was complete. And guess what??? It worked:banana:. Imagine that. It amazed me how much louder and crisp the little RCA became after a re-capping. I've got a few more radios to do and then it's off to the Admiral TV.

Way to go cdmarion! You're well on your way! Glad to hear things are going well. It's really satisfying to spend time replacing components and then have your radio/television work - and work better than it did when you first got it. So, how was the first project? Run into any problems? What kind of set was it - the chassis type or circuit board type?

See - and now you have something to listen to while you work on future projects :)

-Ian

The radio is a RCA model X-551 1952. Everything went great, i had to dig for a couple of paper caps but i just took some pic's and notes to make sure i got things back where they belong.

The only problem i had was when i first turned it on all i got was a low hum and i noticed that tube 12BE6 was not lit, i thought this is great, i get to do some real troubleshooting, i double checked the tube and even replaced it with another and still had the same problem. So i started looking under the chassis and found some solder bridging a couple tube pins, i cleaned the solder off the socket and she fired rite up and the rest is history.
Lesson learned is to be more carefull when desoldering, using the desoldering tool is all about timing and that time i was a little off.

I've been listening to this thing almost non stop and it's doing great.

Next project which i will start on when i'm done with this post is a 1951 Bendix model 526A. This one has a loud hum but distorted audio can be heard. I've got a good idea why the hum and how to fix, i'm looking forward to seeing if i'm rite.

So far i'm having having a ball!!:D I'll keep you guys posted.

Chris

Just found the Markus book I mentioned online at http://www.pmillett.com/technical_books_online.htm

There are some other good books there on tubes and equipment ... Enjoy

Execellent link!! I downloaded the Markus book. Looks like a great book.

Thanks

Ok, i haven't posted in a while. I've been re-capping radios and reading books. Last Sunday I decided to take the plunge and start on a TV. I ended up buying a CRT tester on Ebay and as soon as it got here I started testing crt's in the TV's I've got. I had originally planed on doing an Admiral TV that I bought for $35 but the picture tube tested bad. So I went for my other Admiral, the Tele-Bar. It took me five days working a few hours after work and Saturday. I recapped the TV and radio, tested all tubes, replaced the HV Rectifier tube and fuse and alot of cleaning. I should add that the Tele-Bar was completely dead with exception of the radio when I got it. So I brought it up slowly on the Dim-Bulb Tester.....No smoke or strange smells. Then I took her all the way and guess what.......................It worked (haven't checked the radio yet):banana:. I adjusted the picture in with the front controls. It still needs a little tweeking, and the picture seems a little dark but very watchable as is. I haven't put it in the cabinet yet, I plan on doing some cabinet touch-up before I put everything back together.

I could go on and on but I won't. I have to thank everyone in this Forum that helped me. You guys got me started when I didn't know where to start. Really, I couldn't have done it without you guys. Thanks!!:thmbsp:

All I can say is THIS IS REALLY COOL!!! :D

Chris

Although not recommended, it is possible to begin a restoration hobby by starting with a television. I had never fixed or restored ANY electronic device, ever, before I embarked on a complete electronic & cosmetic resto on a 1947 RCA 630TS.

I didn't know a non-polar cap from an electrolytic before I began, but, with the help of friends on and off line, I learned fast.

The result was a restoration that would stand up to anybody's scrutiny. It can pass for new out of the box, right down to the Labels.

To All Beginners, Best of Luck, and don't be bashful about asking questions. There resides a veritable Brain Trust of Electronic Knowledge on this Website.

Sincerely;

LJB:smoke:

Nice work! Looks great! Congratulations on the success of your first TV project. There will be many more to come, I'm sure :)

With that set - does it have an aluminized picture tube? If not, it uses an ion trap. A misadjusted ion trap will result in a dim picture, even on a good tube. Basically.... the early picture tube coatings weren't too sturdy. The electron gun will, as a result of operation, emit ions. These ions are "heavier" than electrons, and if allowed to hit the phosphor coating, will wear a hole in it - resulting in a dark spot. So, to avoid this, they simply aimed the electron gun downward a bit. This way, the ions would go harmlessly into the bell of the tube, not the screen. But, then again, so do the electrons. But wait! Electrons can be redirected by a magnet. Heavier ions can't (at least not as easily). So, by using an ion trap magnet, they could bend the electrons back where they needed to be, and leave the ions to fall to the bottom. Later tubes came out with a aluminized screen, that was impervious to the ions, eliminating the need for this system entirely.

On your other Admiral - how weak did the tube test? You can get a watchable picture on even a very weak tube. Another "trick" to bring back a weak tube is to run it for a while, on just slightly higher filament voltage. Stay away from the "rejuvinate" function on the tester except for a last resort. Sometimes, a tube that's been sitting forever will come back after even just running in the set at normal voltage for a while. Something to do with the cathode coating. So, if the tube is in the red, run it at say, 7 or 8 volts (assuming a standard 6.3v filament) for a couple hours. Come back and switch it back to the normal voltage, let it run for a minute, and check the emissions, and do a life test. You might be suprised.

I have an Admiral (one of those bakelite console-ettes) with a 14" rectangular tube. When I got it, it had a brightner on it, and had a G1 to cathode short. With the tube tester, I was able to blow out the short (using remove shorts), and bring the tube back into the green by running it hot and using "clean and balance" on the tester. It's definitely watchable now. A bit dim, but watchable.

-Ian

Adjusting the ion trap cured the brightness issue. Now it seems that the top of the picture is shrinking and things at the top of the sceen are squashed. Also the sides of the picture seem to be shrinking with little change from the rear chassis adjustments. I'm thinking Horizontal Output tube? Any ideas?

Chris