Hello All,
The FM RF tube was miswired. The junction of C402, R413, and C403 was wired directly to pin 7 of the 12AW6 with an incorrect jumper from the solder terminal. Instead of a jumper from pin 2 to pin 7, the 47 ohm R401 was in that place. I disconnected the ridiculous jumper from that component junction and left one end of the 47 ohm resistor to there (pin 7). The other end of the resistor is connected to the correct junction of the above mentioned components on the solder terminal. Another jumper is connecting pins 2 and 7 correctly. One end of the 47 ohm resistor is supposed to be connected to BOTH pin 2 and pin 7. The other end of the 47 ohm resistor doesn't connect to a pin on the tube at all. Now all I need is a 51 pf capacitor and I can connect the 5 ohm (two 10 ohm resistors in parallel), between C401 and pin 1 on the 12AW6. Even without the 5 ohm resistor in place, shouldn't I hear an FM Hiss? I don't. It's total silence in the FM position.
Where do I look next. All the paper and electrolytic capacitors have been replaced. The detector diodes work because they are used in the AM position as Detector and AVC. They work perfectly.
There were a bunch of burned resistors. R400 was burned, R401 was burned, R412 was burned, another resistor was also burned. I belive it was R303. There is another low value resistor R404 which I could have replaced. I'll double check.
The way it's operating, it's as if something isn't being powered up.
I see no way R400 could have been burned, except by a lightning strike or from someone connecting line voltage to the antenna terminals, after removing the 51pf capacitor and just directly wiring it.

Please help if you can. I'll keep studying this set. Maybe there's yet another burned resistor to replace.

Thanks,

Dave

Hello Again All,
All the tubes test very good. No problems. So I have no idea what's wrong. But I'll keep looking.

Thanks,

Dave
:Hello All,
: The FM RF tube was miswired. The junction of C402, R413, and C403 was wired directly to pin 7 of the 12AW6 with an incorrect jumper from the solder terminal. Instead of a jumper from pin 2 to pin 7, the 47 ohm R401 was in that place. I disconnected the ridiculous jumper from that component junction and left one end of the 47 ohm resistor to there (pin 7). The other end of the resistor is connected to the correct junction of the above mentioned components on the solder terminal. Another jumper is connecting pins 2 and 7 correctly. One end of the 47 ohm resistor is supposed to be connected to BOTH pin 2 and pin 7. The other end of the 47 ohm resistor doesn't connect to a pin on the tube at all. Now all I need is a 51 pf capacitor and I can connect the 5 ohm (two 10 ohm resistors in parallel), between C401 and pin 1 on the 12AW6. Even without the 5 ohm resistor in place, shouldn't I hear an FM Hiss? I don't. It's total silence in the FM position.
: Where do I look next. All the paper and electrolytic capacitors have been replaced. The detector diodes work because they are used in the AM position as Detector and AVC. They work perfectly.
: There were a bunch of burned resistors. R400 was burned, R401 was burned, R412 was burned, another resistor was also burned. I belive it was R303. There is another low value resistor R404 which I could have replaced. I'll double check.
: The way it's operating, it's as if something isn't being powered up.
: I see no way R400 could have been burned, except by a lightning strike or from someone connecting line voltage to the antenna terminals, after removing the 51pf capacitor and just directly wiring it.
:
: Please help if you can. I'll keep studying this set. Maybe there's yet another burned resistor to replace.
:
:Thanks,
:
:Dave
:

Have come across radios that have been modified to accept similar tubes, but with different pin-outs. Like a 50C5 for a 50B5. If the original tube type was reinstalled it would be a direct short. This may be what has happened to you. This can be a challenge to sort out.
It's all part of the hobby though. This is the kind to put aside, and come back to it when you feel like it.

Warren,
It has all it's original tubes in it. No tubes have been modified.

Thanks,

Dave
:Have come across radios that have been modified to accept similar tubes, but with different pin-outs. Like a 50C5 for a 50B5. If the original tube type was reinstalled it would be a direct short. This may be what has happened to you. This can be a challenge to sort out.
:It's all part of the hobby though. This is the kind to put aside, and come back to it when you feel like it.
:

Hi Dave,
There is something really fishy here. Why would someone deliberately miswire the radio then use it?
Consider that the schematic was wrong, unless the other wiring was really goofy.
If you had some weak tubes (which you don't) I would be really suspicous. Even with all the tubes good I would have some suspicions of the schematic.

Best Regards,

Bill Grimm

Bill,
There was evidence of circuit changes and the resistors were burned to a crisp and cracked in half.

Thanks,

Dave
:Hi Dave,
: There is something really fishy here. Why would someone deliberately miswire the radio then use it?
: Consider that the schematic was wrong, unless the other wiring was really goofy.
: If you had some weak tubes (which you don't) I would be really suspicous. Even with all the tubes good I would have some suspicions of the schematic.
:
:Best Regards,
:
:Bill Grimm
:

Hi Dave,
Looks like you have a former child's toy there. When I was 13 I did some ugly things to radios.
Do you think that when the resistors burned up one of the RF coils, ANT or oscillator, could have been damaged? If one of them had corrosion it could have failed without a burn.

All The Best,

Bill

Just to add some humor to all this. A 17 year old kid tried to make a guitar amp from an AA5 radio. Went to some silly DIY site. Not only did he shock the hell out of himself, but did burn out the pickups on his fender guitar. I now have what's left of the radio. It's a parts only set.

:Just to add some humor to all this. A 17 year old kid tried to make a guitar amp from an AA5 radio. Went to some silly DIY site. Not only did he shock the hell out of himself, but did burn out the pickups on his fender guitar. I now have what's left of the radio. It's a parts only set.
:

I have nightmares about sets like this, a dear friend or relative brings me a FrankenRadio which has been maimed, and it always has such profound sentimental value. I open it up, and find such nonsense as you have. The restoration can become a crusade, unless you really thrive on adversity.

Anything can be fixed, it's just a matter of time and money. Best of Luck!

:Just to add some humor to all this. A 17 year old kid tried to make a guitar amp from an AA5 radio. Went to some silly DIY site. Not only did he shock the hell out of himself, but did burn out the pickups on his fender guitar. I now have what's left of the radio. It's a parts only set.
:

When I was in high school I made a record player based on the audio output of an AA5 for a school physics project. When you loaded a record you couldn't touch the turn table.

The teacher gave me an F. I deserved it.

Best Regards,

Bill Grimm

Bill,
There was an input jack on this radio, but I removed it because it was unsafe. Maybe this is what caused the burned resistors. This radio has a ton of low value "mica" tubular Philco capacitors. Maybe some of them no longer work. But there's a "ton" of them. Maybe someone can show me which ones were likely to be the culprits in this problem.

Thanks,

Dave
:When I was in high school I made a record player based on the audio output of an AA5 for a school physics project. When you loaded a record you couldn't touch the turn table.
:
:The teacher gave me an F. I deserved it.
:
:Best Regards,
:
:Bill Grimm
:

Those tubular ceramic and/or mica capacitors rarely fail. A Solar model CB capacitor analyzer is a good investment. It looks good and performs well, too. It can tell you so much about the condition of the capacitors in your radio, what values they are, etc.

T.