7 Steps to Troubleshooting Tube Radio
- Removing the chassis. To repair the radio’s interior, you must first remove the outer frame. ...
- Making a sketch. Make sure you know the components inside the tube radio and where they are located. ...
- Inspecting the tubes. Next step, we will test the tubes. ...
- Looking for Burnt Components. ...
- Check Your Speaker. ...
- Check the wire loop antenna. ...
- Plugging the radio in. ...
How can I Fix my Old radio?
How can I fix my old radio? How can I fix my old TV? First steps in restoration. Replacing capacitors in old radios and TVs. Powering up your radio safely with a dim-bulb tester. Powering your old battery radio. How to ship antique radios safely. Where can I find old radios? Would you like to buy my radio? Are your radios for sale? You can find more detailed advice in our Information and Restoration areas.
How to restore antique radios?
Your Original Radio
- Fully disassembled and cleaned
- Structural repairs are made
- We rebuild the radio tuning section so that the original controls can be used
How to restore an old radio?
What I need in order to do a proper restoration:
- Radio must be pretty much unmolested. If anyone has modified the radio I may not be able to restore it to its original condition.
- It must have all original knobs. ...
- Power Transformer working and not burned out. ...
- Speaker not badly damaged. ...
- I do not restore Philco models made in the 1940s that have rubber wiring. ...
How to repair and restore vintage valve radios?
Radios can be fixed using the general methods given in repair books, but many problems require specific answers, and the schematic may include other useful info, such as voltage and resistance charts for your radio. Schematics for US and Canadian radios typically cost a few dollars and can be obtained from the sources in my Parts page.
How do you fix an old radio?
1:5313:49How to Fix Antique Radios - YouTubeYouTubeStart of suggested clipEnd of suggested clipFor especially heavy or valuable radios it's best to remove the chassis from the cabinet. And packMoreFor especially heavy or valuable radios it's best to remove the chassis from the cabinet. And pack it separately.
Do tube radios still work?
Even though they're ancient by today's standards, these old tube radios can almost always be brought back to life, and there's still plenty of broadcasts out there for them to receive!
How much does it cost to restore an antique radio?
Estimates – We charge a flat labor rate for antique radio restorations of $18.00 per tube (i.e. labor for a 5-tube radio is $90). We also charge a 5% labor surcharge to cover the cost of small parts (nuts, bolts, springs, solder, wire, dial string, etc.).
Can radios be repaired?
Most modern radios are built on printed circuit boards that can't be repaired by anyone but trained technicians. However, there still are tests you can perform and parts you can replace.
How do you power up an old tube radio?
9:3914:06How to power up a 80 year old Zenith 9S367 console radio using a variacYouTubeStart of suggested clipEnd of suggested clipSo what I want you to do is turn this knob up slowly hold on you're gonna see that meter starting toMoreSo what I want you to do is turn this knob up slowly hold on you're gonna see that meter starting to go up if that meter jumps. Then turn the knob back down.
How do you test old radio tubes?
Put the tube into your guitar amplifier, tester, or other tube-using machine. Turn on the machine to activate the tubes, and look for an orange, red, or purple glow. If the heated filament inside the tube glows orange like a setting sun, it's usually a sign that the tube is healthy. The filament may be hard to see.
How do I start an old radio?
Follow these general steps to restore your radio:Do not power on your radio. ... Find a service manual. ... Replace all electrolytic and paper capacitors with new ones of similar value and same or better voltage rating.Examine closely and replace anything that looks damaged, such as burned up resistors.More items...•
How do you fix a vintage radio tuner?
5:419:02How to replace repair dial tuning cord vintage AM FM stereo receivers D ...YouTubeStart of suggested clipEnd of suggested clipThere's a tuning needle. They use more of that stupid glue. Okay so take an exacto. Get under thereMoreThere's a tuning needle. They use more of that stupid glue. Okay so take an exacto. Get under there pry up these tabs. And carefully get that string out of there you don't want to damage this. Either.
How do I troubleshoot my FM radio?
How to troubleshoot AM or FM radio reception issues on a portable stereo system or boombox.Ensure the appropriate AM or FM band is selected. ... If possible, relocate the position of the antenna.Ensure fresh batteries are installed.Move the portable stereo system to another location.
How do you fix a car radio that won't turn on?
The first thing you should do when your radio stops working is check its fuses and replace any that have blown. Also, if you have an after-market stereo head unit that is meant to be easily removed, be sure to check the back of the unit itself for any fuses.
How long do radio tubes last?
Power tubes like EL34's and KT88's are good for about 2500 hours or more. But may go longer in an amplifier with a conservative design. Small signal tubes with numbers like 12AX7, 12AU7, and 6922, and rectifier tubes like 5AR4 may go 10,000 hours. So you get years and years of enjoyment.
Are vacuum tubes worth anything?
There is a large market today for newer tubes used in vintage music amplifiers and vintage tube stereo equipment. Sought after by Audiophiles, these include the common U.S. made 6L6 ($15-$25) and 12AX7 ($8-$15). If it's a Telefunken brand you can easily double or even triple the price.
Why did radios have vacuum tubes?
A vacuum tube, also called a valve in British English, is an electronic device used in many older model radios, television sets, and amplifiers to control electric current flow. The cathode is heated, as in a light bulb, so it will emit electrons. This is called thermionic emission.
Did radios use vacuum tubes?
VACUUM TUBE RADIO. By the late 1920s, vacuum tube radio equipment replaced the primitive spark-gap systems on most merchant ships. This new equipment could send and receive signals virtually worldwide, by using high frequency or "short-wave" bands.
What is an AA5 radio?
Sometime in the 1930's, somebody figured out that you could build a radio without a power transformer. Power transformers are expensive, maybe the most expensive single part in the radio. Do away with it and you save a bit of cash. This design became known as the All American Five. No transformer and five tubes. The voltage of the filaments all added up to about 120v. We'll refer to it as the AA5 from here on out.#N#The AA5 design was produced by the millions in many different incarnations using a variety of tubes. As new tube designs appeared, they made their way in to the AA5 design. You can find AA5 radios that use both 1930's designed tubes and 50's era miniature tubes on the same chassis! Despite the different tubes they used, they all follow a very similar circuit design and are an easy radio to learn to work on. There are derivatives of the AA5 that used more or less tubes but they all had the same thing in common, no power transformer.#N#Before cracking into that antique radio, we need to stress a few words of caution. An AA5 radio can kill you if you're not careful.#N#How can a radio kill you? Back to the history lesson! The AA5 radio and its derivatives use no power transformer. To pull this off one side of the line cord was connected right to the chassis. Keep in mind this was back in the day when natural selection was more the responsibility of the user and not the manufacturer. It's very important to not try to work on this radio while its plugged in. You also need be very careful not to touch any metal parts or exposed screws on the radio when its plugged in as they can be energized at line voltage potential.#N#Ready to dig in? Let's go!
What is an AA5 antenna?
The antenna. Most if not all AA5 where equipped with wire loop anten nas. These antennas consisted of many feet of enameled thin copper wire in the form of a coil about 6-10 inches in size. The coil was usually mounted on the back cover of the radio but sometimes was even part of the cabinet.
What does a tube radio smell like?
Tube radios exude a particular smell unlike any modern equipment . The heat of the tubes on the dust inside the radio, the contact cleaner you used, the insulation on the wires, the old waxed fabric cord, all exude their own smell. Most old radio fans immediately identify it as tube radio smell. Its normal.
How to fix an electrodynamic speaker?
I have successfully used paper towels, rubber cement, and spray paint to fix old radio speakers. Use a fresh container of rubber cement so it flows easy. Gently apply a thin coat of rubber cement to what's left of the speaker.
What are the different types of capacitors in a radio?
There are other types of capacitors in the radio. There may be plastic encased paper, plastic encased mica, ceramic disc, variable air, variable mica and ceramic tubular. The plastic encased paper caps should be replaced per several sources I have read but I have never had a need to.
How to remove a tube from a socket?
For very stubborn tubes such as LOKTALS you may have to carefully use a flathead screwdriver to pry the tube free of its socket. Be careful doing this so you don't damage the tube or the socket.
How to fix a broken speaker cone?
Gently apply a thin coat of rubber cement to what's left of the speaker. Once its coated with glue, cut a piece of paper towel to fit the repaired area and carefully lay it in place. Gently press the paper towel in place with your finger tips being careful not to make any further tears in the old cone.
How To Troubleshoot Tube Radios – Step By Step Guide
We’ve talked enough about tube radios. Now’s the time to get down to work.
Frequently Asked Questions With Answers
A: You will need to replace many of their components, such as faulty tubes, bad speakers, broken wire antenna as well as many other burnt components.
Verdict
We hope that our article was useful to you in trying to restore a tube radio.
How many oscillator coils does a radio have?
This radio has three oscillator coils total: one on its own coil form beneath the chassis, and two wound on the same coil form and mounted up next to the variable capacitor on the top. Measuring the lower oscillator coil. The other two oscillator coils sharing a common coil form on top of the chassis.
What is a Dewald 618?
In this five-tube AC/DC radio, the antenna picks up the transmissions and couples them through a set of antenna coils which are switched depending on whether you're listening to mediumwave broadcast signals or one of the shortwave bands, and help to pre-select the signal going into the next stage of the radio to reduce interference and undesired reception.
What happens if you plug in a radio without refurbishing it?
This generally means a burned out transformer and a dead radio , and is one of the most common outcomes if you plug in a radio you've found without refurbishing it first.
What does infinite resistance mean?
An infinite resistance reading means there's a broken wire, but good readings might range from a few ohms on the low end to a few dozen on the high end. Measuring the primaries of the antenna coils. One good trick for measuring the primary of the antenna coils is to take advantage of the radio's built-in wiring.
How many tubes are in a project radio?
Finally, if you've found a project radio to start on with more than six or seven tubes, you might want to find a smaller model to practice on before diving in — especially if the radio has any sentimental value to you.
What are the signs of a radio?
Bite marks and chewed wiring are a major warning sign. Generally, a radio that's been infested isn't worth even attempting to fix due both to the damage that may exist and the fact it's a serious health hazard. A vintage radio chassis infested with mice. Not a good candidate for repair!
How do vacuum tubes work?
Vacuum tubes operate on the principle of thermionic emission, where certain metals heated to white-hot in a vacuum will give off electrons. The flow of these electrons can then be controlled by charges placed on the tube's internal elements. The first practical vacuum tubes were invented in 1907 by Lee DeForest, who developed the "Audion" — the world's first triode capable of amplification. This ushered in the radio age, but it wasn't until about 20 years later that radio finally left the lab and made it to consumer's homes.
What is a dental pick?
The tool shaped like a dental pick is a stainless-steel hobby pick, handy for removing snipped pieces of wire from a solder terminal. The small metal alligator clips are used as heat sinks; you can clamp them onto the lead near a delicate component, to prevent overheating while it's being soldered.
What is signal generator?
A signal generator is also useful for realigning radios and TVs, although that specialized procedure isn't always necessary.
What is tube radio?
Tube-powered radios are simple in comparison to modern electronics. Most were built to conventional designs and they use replacement parts that are still readily available. Fixing old radios can be an enjoyable hobby and you can also learn about a key technology of the modern era.
Is it easier to use an analog meter or a digital meter?
In a few cases—notably, aligning radios and TVs—it's a little easier to use an analog meter, which displays a value with a needle on a scale; when you're turning an adjuster back and forth, seeking a peak point in a range, it's easier to watch a swinging needle than to decipher a changing stream of digits.
Can you fix a radio?
Yes, especially if you're a beginner. Radios can be fixed using the general methods given in repair books, but many problems require specific answers, and the schematic may include other useful info, such as voltage and resistance charts for your radio.
Can you put your hands inside an old radio?
The repair books explain how to do this work safely. Never stick your hands (or anything else) inside an old radio if you don't know what you're doing.
Is a tube reliable?
Tubes are comparatively reliable, and there are other ways to check them. My article First Steps in Restoration explains how to perform a simple dud/not-dud test on a tube using an ohmmeter. You can also substitute a known-good tube in place of a suspect tube, to see if the radio or TV plays better.
What capacitors decay with age?
There are several flavors of capacitors but the ones that typically decay with age are the electrolytics (usually found in power supply and on audio output circuit) and the wax-paper coupling capacitors. Find a service manual. Most are available online.
Why are TRF radios so expensive?
TRF architectures are expensive because to maintain a narrow 10 KHz band pass filter across one full octave is challenging and requires more precision than using only one fixed filter that can be mass-produced and is at a lower frequency. Example of a TRF radio architecture used in the mid-to-late 1920’s.
How many sections are in a heterodyne receiver?
Heterodyne receivers cost significantly less than the previous architecture known as tuned radio frequency (TRF), where the radio was simply a very large tunable bandpass filter (3 or 4 sections typically) with amplifiers between each section that had to tune across the entire AM broadcast band.
Why is my tube radio bad?
Often a bad stage in a tube radio is due to a resistor that has increased in value to the point of biasing the tube into cut-off. Tubes are usually not what caused the radio to be put out of service. The quickest way to find bad resistors is to probe the tube pin voltages.
What was the radio in the 1950s?
By the 1950’s radios were everywhere. FM broadcasting started to gain popularity with its high fidelity. Table top radios such as this one provided both AM and FM broadcast bands in a compact package with 1950’s styling much like automobiles, jet aircraft, rockets, tail fins and chrome, and other exciting technologies of the day. This radio in particular uses negative feedback in its audio output providing booming high fidelity audio. Unfortunately, it is a Hot Chassis radio, where the line cord is tied directly to the metal chassis inside so an isolation transformer must be used in-line with the power cord while servicing.
Do old radios work?
Most antique radios will work once the capacitors have been replaced. If it does not work then signal trace through the circuit by injecting a signal at the IF or RF, replacing resistors or occasionally a tube where needed. Old resistors have a tendency to increase in value with age.
When was the console radio invented?
Here is an example of the iconic American Console Radio. This radio, manufactured in 1937, was witness to much history: the Great Depression, the Second World War, and probably the Korean war War as well before it was put out of service. This generation of radio was the first to leverage heterodyne receiver architecture.