I've been into old radios since I was a kid, now I'm struggling to learn how to fix them. I've gotten a few successful repairs under my belt but I keep getting stumped. I have a lot of reference books including Elements of Radio Servicing which i read regularly. I have an excellent grasp on how superheterdyne (and other) receivers work, however I'm falling short in the service and repair department. I've had lot's of advice from forum members that I'm very appreciative of but talking to folks on the internet is no substitute for hands on instruction. I learn best by the old apprentice system, which of course is no longer in place. Does anyone know of a resource for practical side by side instruction in the repair of these electronic classics ?

Thanks....Yet again

I apprenticed myself for two junior-high summers at the local radio-TV shop (mid-1960's), so I understand where you're coming from. I had a good boss and tutor, and it was just about the best possible start I could have made.

The boss also made sure, however, to give me a number of books to keep, and I've kept them. Over the years, I found more that were just as valuable, especially for guys just starting out. They won't take the place of a side-by-side tutor, but for a thorough grasp of fundamentals (which will help you reason things out much sooner), they're indispensible.

Sending a PM that should help.

Larry

Hi,
Just wanted to say that I compare it (troubleshooting) to the game of golf. It's pretty darn frustrating until you get the hang of it, and the "fun" factor increases with experience. I get stumped too, and come to this forum for help. Each time is a new opportunity to learn something.

I've thought of asking one of the senior tech members to participate in a mentoring arrangement, but that's too much to ask in my opinion. The forum is the next best thing, and I read lots of threads just to pick up knowledge.

Some years ago there was a group participation here (before I joined) where they went through Elements of Radio Servicing chapter by chapter, one per week. Folks could discuss and ask questions as needed. I'd like to see this done again...

Cheers,
-Sam T.

I'd like to see it too.

Larry

the first basic skill is soldering. you can practice on a board with small brads pounded into it hooking a piece of copper wire making good solder joints. lots of tutorial info on the internet. YouTube has live video for all things electrical and electronic including soldering and old radio repair. I learned soldering from my Dad on the bench when I was seven or so. the space program sent him to soldering school so not to make the rocket payload too heavy. thats how important good soldering can be

Yes! I ran into a frustrating snag with my first radio a few weeks back, and have been trying to poke around with this book before I start troubleshooting. A play-by-play with the veterans would be very helpful, and a lot of fun to read.

Mike

Thanks to everyone for their input. I've had good luck with learning the physical skills of repair. That is soldering, cleaning etc. Where I'm falling short is troubleshooting. Now, I understand going stage by stage taking voltage readings and injecting signals, but interpreting the results of these tests is till flummoxing me. I'd also like some hands on with things such as the old trick of using a cap and a resistor to bypass a faulty IF transformer.

One thing I would recommend, along with the Elements of Radio Servicing, is practice in learning how to navigate between a schematic and an actual radio.

What I would suggest is using an already working radio of perhaps 50's vintage and nothing real elaborate. It can be an All American 5 (AA%) type set or a small power transformer type set. However, it needs to be one where you can get a good readable schematic (not one where you can't tell one blob from another).

Make yourself a nice copy of the schematic (maybe more than one) because you are going to write all over it.

You are starting with a working radio because you don't want to deal with a radio that someone else has already mis-wired which will just cause a lot of frustration or confusion.

On the schematic, if it doesn't show all the pin numbers for the tubes, go find information on each tube and transfer the pin numbers of each tube element (grid, plate, screen, cathode, etc.) to your working schematic.

Get yourself a highlighter.

Then find something you recognize in the radio (say the rectifier), and find it on the schematic and highlight it. Then pin by pin, find any part that is connected to the rectifier and identify it on the schematic verifying values marked on the parts as you go and highlight each on on the schematic.

You can work through this tube by tube, or you can follow paths like a road map from tube, through resistors or capacitors to other tubes and so forth. Each thing you find, highlight it on the schematic.

As you do this you hopefully come to realize that all things attached to the same "line" on a schematic are actually connected to each other, but not necessarily in the order you will see on the schematic. For example, on a schematic you might get the idea that a wire will go from component A to B and then to C. In the radio you might instead find a wire from A to C then to B. You might just as well find a wire from A to B and another wire From A to C. All of these are the asme electrically as long as A, B, and C are connected.

Eventually your whole schematic should be highlighted and you will have found and identified every part in the radio and will have learned a lot about how radios are put together.

Get used to common designations for parts as you go like R1, R2, R3, C1, C2, C3, L1, T1, V1, etc. Of course, unfortunately, on very old radios some of the "conventions" were not present at the time and can lead to a lot of confusion (which is why I don't recommend trying to learn on a 20's or 30's radio).

Confusion factors on very old radios include things like M meaning thousands rather than millions on ohm markings, having every 1000 ohm resistor on a schematic called number 3 no matter how many there are along with some virtually unreadable schematics and really odd tube symbols.

Another other big thing to learn is Ohms Law. Then some basics of how a vacuum tube works.

Just some thoughts.

Curtis Eickerman

Curtis,

I'll definitely take your advice to heart. You are absolutely right, one of the hardest things to get through your head is that a "schematic" isn't a "layout"....I would love it if everything were put together like the underside of an old Atwater-Kent breadboard where it's almost as though the schematic were rendered in nickel covered square section wire.

I know I've got the ability and desire to repair old radios (and other things) it's just going to be a question of honing it through time, trial and error. I'v had some successes already with simple AA5 type radios, but I'd like to work my way up the food chain and eventually tackle classic TV sets. But I know with their super sensitive circuitry and high voltages they are NOT for the beginner.

Marcus and Levy also wrote Practical Radio Servicing, it deals mostly with the AA5, it's a great book to learn from.
I prefer the 1955 edition. It's like a school book for learning repairs, they have you take an AA5 chassis and use it as a test radio, they show you how to cause a problem in the set, such as bad caps or resistors so you can actually hear what each problem sounds like. They also take you step by step through the trouble shooting process. I read this book a lot, I would not want to be without it.

honing schematic reading skills is a definite must. understanding circuits may be helpful beforehand. read-up on simple resistive circuits then capacitive circuits and induction coils, transformers and the like. mostly failures have to do with continuity. is it a continuous circuit. point 'A' to point 'B'. thats why voltage checks are important. no voltage means no continuity. there is a break in the circuit somewhere. best to have the power supply working first thing so you have voltage to check. being familiar with your meter is essential. DC, AC, ohms. practice testing batteries, AC outlet, capacitors, diodes, transistors, light bulbs, resistors, coils, transformers, speakers. YouTube has a lot of illustrated videos on these topics. next best thing to being there.
this guy talks kinda slow but has a lot of this type tutorial if you click his name
http://www.youtube.com/watch?v=jG7ok3h8 ... A07C5E61A3

Not a tutor but maybe as close as you'll get from a book... Fixing Up Nice Old Radios! by Ed Romney, 1990. After some basic theory, it get's quickly into repairing. As it traces radio developement, it uses specific radio models to illustrate specific repair issues . It's in a very readable style, though it may take a few times through a pargraph to get the point being made. One thing he mentions is to make a copy of a schematic and then, using different colors, trace the flow of the A+, B+, RF, AF, etc.

Different people learn in different ways, and this book presents in a slightly different manner then most. It's not a traditional textbook. It really worked for me. Well worth the effort.

A few problems:

1) Because it's self published (low cost), an original will look like a third generation copy. Pictures just usable. No color.

2) Hard to find and can be expensive. Try for an inter-library loan which is usually free.

3) It ends at 185 pages; I wish it went on much longer.

Greg, I'll order it today ! Thanks

You can try this site, it's free, and there is just tons of stuff. Even with fast connection some of it takes a little while to download.

http://www.tubebooks.org/technical_books_online.htm

Easy wrote:
Some years ago there was a group participation here (before I joined) where they went through Elements of Radio Servicing chapter by chapter, one per week. Folks could discuss and ask questions as needed. I'd like to see this done again...

probably could find this in the archive if you use the search button at the top of the page. I dont see why it wouldnt still be there

I to have decided to learn how to repair radios. I have always been good with the basics of electronics and could solder in replacement parts. But I do not know how to trouble shoot.

After reading Elements of Radio Servicing I thought the best way to learn is to dive right in, so I bought a Crosley Fiver that does not work and decided to strip it completely down and build it back up with new resistors and caps. I am learning a lot as I go.

That's how I started too. I had an old Packard-Bell AA5 in the garage which just hummed like mad when you plugged it in. I re-capped it, with great trepidation I might add, and on turning it on lo and behold it worked perfectly. Now, that was a simple repair and I was lucky that there was nothing further wrong with the set. But that first experience of getting your hands on a real radio project is really important. It takes much of the mystery away. I've learned a lot from that first radio, but I still have a long way to go.

troubleshooting is understanding circuits. basic electricity. electronics
electricity is AC or DC. electronics is resistors, capacitors, tubes, transistors, ICs
first you must get familiar with meters. VOM. DVM. VTVM. what ever you have use it
test different things with your meter. set to OHM. try the different scales. test across a simple switch. turn the switch OFF/ON. watch the meter change. open. short. test a resistor. read the color code. find the scale on your meter that best tests the value of the resistor. test a capacitor. watch the meter change. what does it mean ? test the filament of a vacuum tube. check a diode. why does a diode read in only one direction ? all this using OHM scale. this is electronics
switch meter to DC scale. read some DC voltage sources. battery. DC power supply. your radio has a DC power supply. identify it.
switch meter to AC. check some AC voltage sources. wall outlet. your radio has an AC source. where is it ? check it with your meter through the switch
changing capacitors in a radio is like changing a light bulb. if you dont know what it means its about the same thing

Yes, you are doing the right thing. So long as you don't fry the coils, just about everything else will fall into place. You will learn how to unsolder as well as solder among other things. Should you bust a tube socket or whatever, let us know, someone will give you a spare.

You can always place a WTB on the classified forum here, but be very specific about what you want. Members here are very fair and friendly.

If you think you may want to continue on, I would suggest you buy an assortment of often used capacitors and resistors to have on hand. Jameco for one, has some pretty good stuff, and sometimes Ebay has good deals for parts from you know where. Also Just Radios is a champ for the hobbiest. I've had good luck with all. Standardize on 630 volt poly caps and 350 volt electrolytics, and one watt resistors and you will be OK 99% of the time for old time radio restorations. Oh, yes, 400 v silver micas 10,22,47,110,220,330 Picofarads, a few of each and you're set. Can parallel them to meet your needs.

Thanks for all of the suggestions ! Just to let you guys know, I have successfully repaired one of the two Airline radios that were haunting my bench. No small thanks to everyone on the forums...

Cheers !