Hey folks. I have a GE Radio Phonograph Combination 118, which has a few issues.
-Humming noise comes on after 5-6 seconds of being powered on. The volume control was not making any changes; it just kept getting louder.
-The turntable is not spinning. I'm guessing it is missing a belt, and I see something else that seems to be broken, which I'm not able to identify yet. Would this work? https://www.amazon.com/dp/B08736RZ9V
I've uploaded a few photos and PDF files, hoping to find the right way to do this. I've previously done a small repair on a Bose radio. I also have the schematics, but I didn't get everything yet, I think. It is a limited download amount. The schematics I'm using are from https://www.radiomuseum.org/r/general_el..._id=2#data .
I'd like to confirm whether I should replace these.
[*]-Filter electrolytics bad
[*]-Power supply
[*]-Leaky paper caps
-(Above I've yet to ID on the schematic)
-Item #47 - GE Part # RTO-038 (This is on the schematic)
Any other suggestions/comments are welcome. Thank you!
1. Before even powering off, replace ALL paper caps and ALL electrolytics. I wonder why no one have told you that. This is the basic basic.
You are lucky upon power-on that thing did not smoke or damage your rectifier etc.
2. "Replacing power supply" makes little sense as there is no, strictly speakling, a block here that one would call "Power supply". As said before:
- Remove the tubes.
- Check the tubes
- Replace every single paper cap in whatever shape and form it comes. If inclined to do so, restuff with new to keep the looks (few people do that).
- Do not touch ceramic/mica caps if present, unless later diagnostics confirms one bad.
- Replace evry single electrolytic cap.
- Do not use old electrolytic caps as solder posts. If want to keep'em, ether cut the wires altogether, or restuff with new (if inclined to do so).
Then power up, use Variac.
- IMPORTANT: use isolation transformer: this is an AC/DC set with no transformer, so if you are very unlucky, you will at some point complete the circuit and be shocked/very amazed/killed.
Good luck!
And Welcome!
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
Hi Toucan Radio,
First off, welcome to the Philco Phorum, a Phamily Phriendly Phorum Phull of Phine Pholks and Phun Philco Phacts. (See a pattern here?). Please take some time to surf the Phorum, read our rules and regulations, look at the Philco Library and don't forget to stop into Old Ron's Bar and Grill for a virtual burger and brew, and to shoot the breeze with the gang!
Secondly, sorry for the length of this post.
Now, to your radio. It appears to be in absolutely outstanding condition and unmolested.
+1 on Morzh's advice. This radio does not employ a power transformer except the small metal cased transformer on the top of the chassis that supplies the Phono Audio tube. You will hear several warnings regarding working on this set. Please do not be discouraged or offended. You CAN do this; we just want you to be safe.
If you do not have the complete schematic for the set, you can find it on Nostalgia Air. For your convenience, I attached a link here:
First, let me discuss the radio. Your set has 6 tubes but the radio section is a very common configuration that radio hobbyists call the "AA5" or "All American 5 tube radio. This is a circuit that the radio manufacturers of the time came up with that was inexpensive to build and provided reasonable performance. If you can read schematics and if you go to the Nostalgia Air website, you will find the schematics of almost all American radios built between 1920 and 1953. you will find that many of the different manufacturers' AA5 sets to be similar.
The AA5 radio consists of a half wave rectifier (usually a 35Z5 or 35W4), an audio power output tube (usually a 50L6 or 50C5), a 1st audio amp / detector / AVC (Automatic Volume Control) tube (Usually a 12SQ7 or 12AV6), an IF (intermediate frequency) amp tube (usually a 12SK7 or 12BA6) and a pentagrid converter (oscillator / mixer) tube (usually a 12SA7 or 12BE6). All of the tubes except for the 6AC7 are extremely common and can be had for very reasonable prices from various suppliers on the internet or on "The Auction Site" (eBay).
This radio uses the "Superheterodyne" principle where the incoming signal is mixed with a signal generated by the oscillator that is 455KHz (Kilohertz or thousand cycles per second) higher than the frequency of the desired radio station. This produces a signal at a "beat frequency" of 455 KHz, which is amplified by the IF amplifier. The signal then passes through the "detector" where the audio signal is stripped from the radio signal, then passed to the volume control, the 1st AF Amp, the Audio power output tube, then finally to the output transformer and loudspeaker.
Since these circuits run on direct current and the wall outlet supplies alternating current, the rectifier tube changes AC to pulsating DC for all of these circuits. the pulsating DC is further filtered to ripple free DC by the large electrolytic capacitor at the bottom of your under-chassis picture denoted as C14A and C14B on the schematic.
Please note that the phono motor requires alternating current.
Please supply a photo of the complete topside of your turntable (record changer). This changer usually employs a "capstan" roller to couple the motor to the belt. Since this set is nearly 80 years old, the oil and grease used to lubricate the turntable have likely dried up.
It appears that this is a 78RPM only changer, but it employs the GE RPX magnetic cartridge, which is far superior to the crystal and ceramic cartridges of the time, providing better fidelity with much less distortion. The magnetic cartridge does not put out a signal as strong as the crystal cartridge, hence the 6AC7 phono audio tube which provides 2 stages of audio amplification. Disassembling and lunricating the turntable should not be terribly difficult. If I find service instructions for this turntable, I will post them.
It is important to note that this is a "warm chassis" set. Since there is no transformer to isolate the chassis from the power line, care needs to be taken. the only connection between power and the chassis should be through Capacitor C20 and resistor R7. This connection is necessary to block (or limit) low frequency current but allow RF to pass.
It is standard practice to replace all capacitors in a radio before powering the set up. These capacitors degrade over either age, use or both, and either will short or open. The big capacitor on the bottom of your under chassis picture is a dual 50 uF (Microfarad) electrolytic capacitor, labeled C14A and C14B. This is the filter capacitor for your set and is definitely BAD. They always are when they are this old and is the likely cause of your hum. Another electrolytic capacitor, C21 also needs to be changed. Please note that electrolytic capacitors are polarized. You will not likely find a direct replacement for these capacitors, especially C14A and C14B. To replace this capacitor, use 2 separate 47uF 200WV (working volts) electrolytic "caps" (capacitors). Tie the negative terminal of the 2 replacement "caps" together and connect to the black wire from the original "firecracker". The positive leads go to the red and green wires. Cut the wires at the old capacitor, slide 2" of "heat shrink tubing down the remaining wire as far as you can. Strip 1/4 " off the wire. Slide 3/4 of heat shrink tubing on the leads of the new "caps". Bend the ends of the leads of the new caps into "hooks" and crimp around the bare section of the wire from the old cap. Solder the connection, trim off sharp edges and slide the heat shronk tubing over the connection to insulate. Do the same to C21. Use a 5uF 200WV cap.
All of the other caps should be replaced as they dry out and can, in fact, short out. These are usually "paper foil" caps. These can be replaced with mylar caps rated at 630V. These are generally not polarized. Some people will "stuff" the old caps with these newer mylar caps to retain the original look. Don't bother doing this on your first restoration. This is not a high value set and the only people that will see the "restuffed" caps are those that take the radio apart to inspect it. The easiest way to replace these caps is to cut the leads at the cap, as close to the cap as possible, clean the wax of the lead, bend the lead into a small loop at each end. Pass the leads of the new cap through these "loops", bend and trim these leads, and solder. Do one cap at a time. This is not the prettiest way of recapping, but for the beginner, this is the easiest by far, and almost foolproof method.
If you have a lot of experience soldering, you can desolder the connections at the tube socket, remove the connection and replace with the new capacitor, but you may find the leads to be not long enough to get from connection to connection. It is also easier to make wiring mistakes and solder bridges using this method. Cutting the wire at the cap and making the connection there is much safer.
Serious collectors have many tools including an isolation transformer and a "Variac". One side of all 120Volt power in your house is at "ground" potential. This is referred to as the Neutral. The other side is 120V above ground potential and is referred to as "Hot" or "Line". If you contact the "Hot" lead and are standing on a concrete floor or outside, or touch a water faucet, you complete an electric circuit with your body and receive an electric shock. This shock can be dangerous or fatal. The isolation transformer provides a circuit that is not referenced to ground, preventing you from receiving a shock by touching the radio and ground at the same time. It does not protect against all shocks such as touching 2 connections inside the radio and completing a circuit. You can test the radio safely by reassembling the radio and installing all knobs and not touching any metal part of the radio when using or testing the radio.
A Variac is a variable voltage transformer. To prevent damage to hard to find parts, an expert restorer "brings up" the radio for the first time on a Variac to prevent damage to sensitive and hard to find components such as power transformers, expensive tubes, etc. Variacs are expensive. An alternative is what is referred to as a "dim bulb" tester. This is merely a 100 watt incandescent bulb placed in series with the radio under test. If there is a major short in the radio, the bulb will burn brightly. If the radio is good, the bulb will be dimly lit.
These radios usually do not have fuses, and a fuse is usually not needed. The heater filament of the 35Z5 rectifier serves as the fuse.
Good luck in restoring this set to operation. Again, do not be discouraged, we are friendly here and will be glad to help you! Post often, ask questions, post pictures and let us know your progress. Let us know when you have successfully restored the radio to correct operation so we can congratulate you and buy you a free virtual round at Old Ron's Bar and Grill!
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis
I can't tell for sure from the picture, but you should fond a "C" Clip on the ale stub that the turntable rotates on. Pull the clip out (Be careful that it does not shoot off into a parallel dimension), and you will be able to lift off the platter. You will likely find that the capstan (the rubber-tired wheel, turned by the motor, which in turn rotates the turntable) has either is seized due to dried grease, is missing the spring that pulls it in contact with the motor and turntable ore has melted.
Again, good luck with your project!
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis
You are right, it is an Idler. But if Toucan is taking one of these apart for the first time a "tire" is descriptive.
Since I try to not take God's Name in vain (though not always successful), I call it an "Au $#!^" clip, because when it flies into that parallel dimension and you do not have a replacement, you shout "Au $#!^!!!"
Toucan, You GO!! Tear into it, you will be successful!!
"Do Justly, love Mercy and walk humbly with your God"- Micah 6:8
"Let us begin to do good"- St. Francis
Most of us use thevoiceofmusic.com for turntable parts, cartridges and needles. Be sure to connect with them on all your needs so you only have to pay for shipping once. This changer likely had a crystal cartridge which may have been replaced. They will help you determine what you can replace a defective cartridge with. Of course if you don't have 78 size records then the decision is moot. You can always add Bluetooth.
I took the easy way out on turntables - I don't buy radios that have them. I like to say that I'm a radio guy, not a record guy. I had my fill of turntables during the decades when I had to maintain and repair them in radio station studios.
I am the same way.
But I made one exception for that 46-1213, and it happpened to have a non-original TT in it.
The other one was a legacy from an old guy, a friend's godfather who had it for all his life (and which hadn't worked for probably 30 or so years serving as furniture) and his widow said he wanted me to have it.
It is a Grundig Majestic 8058, a great radio, and the TT in it was top of the line German-made Perpetuum Ebner. So I just had to.
People who do not drink, do not smoke, do not eat red meat will one day feel really stupid lying there and dying from nothing.
![[-]](https://philcoradio.com/phorum/images/bootbb/collapse.png "[-]")
