Restoring an Old Radio

           You have just got a tube radio from grandma or saw it at an estate sale for a good price. These little radios take you back to a time before TVs, computers, video games, cds and many more things. This was when shows where broadcast on a radio not TV. This will show you how to restore your radio back to the age of radio!


Step 1: Into Your Radio

               You must UNPLUG your radio and unscrew the back of your radio. Then take a look at the inside of your radio. The thing that may look weird is the tubes. Next you'll notice wrapped wire, wire going around the cabinet or something like that this is the antenna. Or possibly a small flashlight bulb. Now DON’T TOUCH ANYTHING unless you are aware of what you are doing or 120 volts could KILL YOU or HURT YOU. Don't do anything unless the instructabls says to.

Step 2: Chassis

                So now here is this block of metal in your radio it is called a chassis (cha-sea). It was used to mount parts for the radio. Now first things first take off the knobs beware many knobs just pull off but before doing so check for little miniature screws. It’s better to check then breaking off the knobs. Just gently pull off the knobs. Now the chassis screws are almost always under the chassis though rarely they are on the side of the chassis just unscrew the bottom screw(s), now if your chassis is on a slant put your hand on it to keep it from falling out.

                So the chassis is out now if the speaker is broken in a little hole grab a piece of paper towel or cloth and some rubber cement (No regular glue or super glue) put the paper towel or cloth over the speaker hole and dab the perimeter of the paper towel or cloth with rubber cement. Now on to the tuning capacitor grab a can of Metal contact cleaner (not for contacts the other kind) and spray it in the side of the top on the tuning capacitor, work it back and forth a few times. If your dial string is broken use heavy duty string (not thread) or anything else or it will break.

Step 3: Safty First

         Now a short lesson on tube radios. In the 1930's someone figured out you could build a radio with no power transformer! It was called the AA5 and no power transformer and 5 tubes. Now many radio companies could build lo-cost radios. The bad things about AA5's the radio had a live chasses. So when a tube went bad you would have to replace it. If you didn't have the radio unplugged it could shock you. Ok so you don't have an AA5. Well still some companies had live chasses so be careful!

Step 4: Tubes

             Now on to the tubes these are the most important part on your radio. The first is the rectifier tube this is what filters out the ac power to dc power. The reason this is there is because all radio tubes run off dc power. Next lets talk about the converter it converts the frequency of the incoming station to the Intermediate Frequency (IF) witch is 455 kc .Next it’s the I.F. tube (IF) stage works on it. This is where the signal is boosted and unwanted stations are eliminated. Now the detector this takes the sound from the radio wave. Lastly the audio amplifier this takes the sound from the station and makes it high enough to go through the speaker. If it is partly silver at the top it is NORMAL if it is on the side it may work it is 50% chances still keep them.

Step 5: Below the Chassis

               So you have the chassis out now this is super important! Now on the top of the tube put a piece of tape. Take the tube out, on the chassis mount put a piece of tape label same as tube that way when you put the tubes back in they'll be in right. Label it 1,2,3,4 ext Now find a support for your chassis (tape chasses, blocks, ext nothing round or the chassis will fall. (Note you should draw out where every things place is on a note pad).You will want to check for burnt components you need to have the right component (does not matter what size it is) be super careful of the capacitors some carried poison don't be alarmed they were dipped in wax.

              Remember to get exact capacitors example: .001mf to 7mf.For electrolytic they are usually somewhere from 20-50mf (the big ones) there are important they filter the DC voltage in the radio they can dry out over time and cause soft or loud buzzing. The big power supply capacitor is actually three capacitors in one. You can substitute three capacitors make sure you get the right capacitors. You can get a schematic from just click on your radio maker and model and the eye icon. Just hook up positive to positive and negative to negative no bad things will happen. By that I mean loud pops, bad smell, and maybe fire.

Step 6: Doubble Check

               Make one last check for broken wires. Also a bad power cord by the cord opening have a stop in the middle use a pair of needle nose pliers to get it out DO NOT PLUG IN A STIFF OR BROKEN CORD. Now if your card is bad replace it with a cord if you know witch side the neutral is on replace with a modern cord. If you don't know replace with a cord with terminals the same size. Or mark a mark by where the lead is for your neutral (small terminal of your plug) this side usually this side has writing. a good way to check is to plug it into the wall flip the plug around after it turns on the one with the less humming is the right side

                If your plug is still good make a mark on the top of the plug facing the ground terminal . Also bad resistors get a tester set it to the ohm test the resistance copy and paste this link this will tell you what color bands meant Also bad dial lamps some radios had it figure into the voltage. So if it’s not replaced it can give a short life to tubes

Step 7: Record Player

          If you have a record player/radio from 1920-40s it takes 75rpm records. Also needles are hard to find:(If you have a 1950-70s record player it takes 45/33 records (usually a switch for 33/45).Many old record players have changers like mine. Many record players are hard to fix you have to get the right motors and switches.

Step 8: Antenna

             Radio antennas are very important without the antenna you wont get any stations. If it is broken it won't work so if you have your old lamp cord you may be able to hook a new antenna on. Remember to test it first like attach it to the two terminals with alligator clips. If you have a zenith radio many have a "wavemagnet" that detaches from the radio make sure its plugged in!

Step 9: Fingers Crossed

              Now if your radio has PASSED all the steps plug it in and turn it on. Wait about 30 seconds for the radio tubes to warm up. Then tune into a radio station. If your radio still doesn't check the wiring again. Also make sure your antenna is plugged in!

Step 10: Polishing

              I don't like sanding the radio down. Then putting your own finish on it. So I use furniture polish on wooden radios I don't recommend boot oil it is greasy. To get all the grime and cigarette smoke off wooden radios use a very fine steel wool like 00 or 01 grade steel wool. Now it may sound crazy it works!! . For bakelite radios I use a sponge and some soap water. Never use cleaning products like scrubbing bubbles finish or anything like that it removed my radios finish so now its metallic instead of shiny.

Step 11: Extras

           Anything still inside the radio should stay in the radio unless you need it for the radio. Don’t touch it because it may break! In this case it is a original label from when it was bought.(1941)

Step 12: Listening to Your Radio

             This Instructable is over so sit back relax and listen on to your radio!!!!!! Please rate and leave your comments. Now keep in mind you should turn on your radio every week at leased one time just like batteries they go bad if not used!



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    6 Discussions


    8 years ago on Introduction

    Electrolytics that dry out can sometimes be saved. The process is called reforming. Basically you apply a lower than normal voltage and then gradually increase it as the leakage goes down ( over a period of minutes to hours ) These links may help:

    Electrolytics that are not reformed a prone to failing in a nasty way.

    1 reply

    2 years ago

    Could someone please rewrite this in English? Thank you.


    4 years ago on Step 6

    Neutral is to the wide blade of the plug.


    4 years ago on Step 6

    replacing 3 wire power cord with 2 wire cord. What happens to the 3 rd wire connected to on off switch?


    8 years ago on Step 12

    This is good, I have read others and want to get my hands on an old radio and restore it. I could kick myself, years ago I had old units.