Hi guys,
First post on the forum. I bought a old am radio at a flee market and was wondering if anyone had a simple diagram of a chassis explaining to me what the parts were, ie-square can, round can. I know what tubes and capasitors are and what they do.
Joe

Joe, generally square cans are often Intermediate Frequency (IF) transformers. Round cans are most often electrolytic capacitors.

If you could supply the manufacturer and model number (usually on a label somewhere) someone here might be able to point you to specific information about your radio.

In the mean time let me refer you to a set of small booklets available for free online to help you learn what you are asking about. Go to the following and scroll down to "Elements of Radio Servicing" and start reading. They are very basic and designed to teach people from the beginning. http://www.antiqueradios.com/archive.shtml

You can kind of skim through them, then go back and read in detail about specific areas of interest to you.

Curtis Eickerman

Thanks for the fast reply. The radio is a GE FE-112. It has a tunung eye. All the tubes are present, I have not plugged it in. My dad wants to replace the caps first.
Joe

The schematic is in Riders 12-57. If you PM your email address I can scan it for you. The print is very small.

Welcome to the ARF Forums!

You can find the schematic here:
http://www.nostalgiaair.org/PagesByMode ... 007827.pdf
There's a chassis layout and parts diagram included.

Hope this helps,
~ Mitch ~

This is a pretty good idea, especially with regard to the power supply electrolytic capacitors that are known to be a serious issue with older radios.

I took a brief look at the schematic and that's one nice radio (RF, Converter, 2 IF stages, and 6L6 audio). Should end up pretty nice. Just one recommendation (or maybe it's 3). Take your time, be patient, and have fun.

Curtis Eickerman

Hey guys,
I just wanted to take the time to say thank you for all the info/advice/help right away to a NEW member of the forum.

You are welcome, and please keep us posted on your progress.

Curtis Eickerman

Hi guys,

This weekend my dad replaced a few caps in the bottom of the radio, and a new power cord. She sprang back to life. I was really surprised at the quality of the sound and the number of stations i could pull in. Only problem is that the tuning eye does not work. From what I see it should be a 6U5 tube. We cleaned all the contacts on the tubes and sockets, but no luck on the eye.
Joe

The eye tube may be burned out. If the heater is good, you should plainly see a slender cylinder of orange down the center of the tube. If that lights up, and the cone-shaped target at the top of the tube is completely dark, then most likely it isn't getting B+ (target/plate) voltage, and that suggests an open feed resistor to pin 2. Check for B+ supply voltage at pin 2 (target) on the tube (may read somewhere between 200-300 vdc, depending on the set). The 1-meg resistor between pins 2 and 4 should also be checked, for these are also prone to open. If B+ voltage is present, check the cathode resistor to pin 5. This is another resistor that is prone to open.

The green glow in eye tubes gets dim with age, but even the weakest one should show some sign of green life when it's properly volted, unless there's an internal short (a rare thing with eye tubes).

Hope this helps and welcome to the Forum.

Larry

You might want to be a little more specific. The filament doesn't light up? The filament lights up, but there is no green showing? The filament lights up, there is green showing, but it doesn't react to signals?

The point being, there is a lot of ways to "not work" and the best advice usually goes along with the best descriptions of the problem.

So, shooting in the dark a little, I will assume the filament lights, either there is no green, or there is no reaction to incoming signals.

If there is no green, check R37 (1 Meg) which can commonly fail. Also check that connection to supply voltage.

If there is green but no reaction check the voltage at the top of R40 to see if it is varying. It should be anywhere from 0 VDC with no signal from a station to as high at -20 VDC for a really large signal from a station.

If the voltage is not varying (or varying only slightly) it will be necessary to track down where it is getting lost. If the voltage is stuck at zero one of the the first steps would be checking for a shorted or leaky C56. Then check resistor R40 (to do this you will have to temporarily take loose one side of the resistor and test it with an ohm meter). Also check R36 the same way (2.2 Meg).

If the signal is varying normally but the 6U5 is not reacting, it could be a faulty 6U5.

Curtis Eickerman

I will check when I get home from work tonight
Joe

Hi Joe, and welcome. Just note that the 1 meg resistor is often contained inside the socket that the eye tube plugs into.

your dad must have some prior experience. thats one complicated set. just the switches alone. working the power supply first is a good sign that there is a knowledgeable person on board and thats a good thing

Right, and also note that the wires serving the tube socket can open, sometimes at the socket, sometimes elsewhere. Any break in any wire will knock out the tube. Not common, but not unheard of, either.

Keep us posted.

Larry