Hello All,
I replaced all the paper and filter capacitors in this radio. SAMS AR-2 or 131-12. It's workng but I hear distortion as if a resistor is open. But which one? The two R11 and R12 aren't open. R13 had a broken lead. So I replaced it will a 3K resistor. Could that be the problem that it must be 2.2K ohms and 3K is too high? When I measure the resistance between the wiper and the chassis or one of the ends of the volume control when the radio is on, the sound clears right up (Yes, it's an odd test). As I turn the volume control up and down There's a spot past which the sound is overloaded and if I turn the volume down below that point the sound is very quiet. So I suspect a broken volume control. The carbon piece is probably cracked.
What does everyone else think? I'll try another volume control and see if I'm right. Fortunately this radio takes a standard volume control. It's a single control with a switch. That should be easy to replace.

Thanks,

Dave

:Hello All,
: I replaced all the paper and filter capacitors in this radio. SAMS AR-2 or 131-12. It's workng but I hear distortion as if a resistor is open. But which one? The two R11 and R12 aren't open. R13 had a broken lead. So I replaced it will a 3K resistor. Could that be the problem that it must be 2.2K ohms and 3K is too high? When I measure the resistance between the wiper and the chassis or one of the ends of the volume control when the radio is on, the sound clears right up (Yes, it's an odd test). As I turn the volume control up and down There's a spot past which the sound is overloaded and if I turn the volume down below that point the sound is very quiet. So I suspect a broken volume control. The carbon piece is probably cracked.
: What does everyone else think? I'll try another volume control and see if I'm right. Fortunately this radio takes a standard volume control. It's a single control with a switch. That should be easy to replace.
:
:Thanks,
:
:Dave

OK Dave, here is my guess: The volume control is the only way the diode plate of the 6Q7 (pin 4) has of getting to negative. What I think it is doing, is the plate is getteng saturated with electrons, and therefore distorts the signal. When you jumper the volume control, which you have given perfect symptons of being defective, the radio works until you remove the Ohmmeter and the diode plate saturates again. I'll bet, if you replace that volume control, you'll have a fine working radio.

Lewis

Lewis L.,
That is absolutely correct. However I just had a test control to use temporarily. This radio plays beautifully. The 3K resistor (R13) in the power supply is no problem. Would there be any difference if I did go out of my way and get a 2.2 K resistor or should I leave the 3K there?

Thanks,

Dave

::Hello All,
:: I replaced all the paper and filter capacitors in this radio. SAMS AR-2 or 131-12. It's workng but I hear distortion as if a resistor is open. But which one? The two R11 and R12 aren't open. R13 had a broken lead. So I replaced it will a 3K resistor. Could that be the problem that it must be 2.2K ohms and 3K is too high? When I measure the resistance between the wiper and the chassis or one of the ends of the volume control when the radio is on, the sound clears right up (Yes, it's an odd test). As I turn the volume control up and down There's a spot past which the sound is overloaded and if I turn the volume down below that point the sound is very quiet. So I suspect a broken volume control. The carbon piece is probably cracked.
:: What does everyone else think? I'll try another volume control and see if I'm right. Fortunately this radio takes a standard volume control. It's a single control with a switch. That should be easy to replace.
::
::Thanks,
::
::Dave
:
:
:OK Dave, here is my guess: The volume control is the only way the diode plate of the 6Q7 (pin 4) has of getting to negative. What I think it is doing, is the plate is getteng saturated with electrons, and therefore distorts the signal. When you jumper the volume control, which you have given perfect symptons of being defective, the radio works until you remove the Ohmmeter and the diode plate saturates again. I'll bet, if you replace that volume control, you'll have a fine working radio.
:
:Lewis

:
:Lewis L.,
: That is absolutely correct. However I just had a test control to use temporarily. This radio plays beautifully. The 3K resistor (R13) in the power supply is no problem. Would there be any difference if I did go out of my way and get a 2.2 K resistor or should I leave the 3K there?

I wouldn't run out and get a 2.2K right now, but some people like their radios to be just as they were as the day they were built, so, on some trip to the parts store, or an order to the supplier, I would get the right value and put it in there just to have it exactly as it was built.
Lewis

:Hello All,
: I replaced all the paper and filter capacitors in this radio. SAMS AR-2 or 131-12. It's workng but I hear distortion as if a resistor is open. But which one? The two R11 and R12 aren't open. R13 had a broken lead. So I replaced it will a 3K resistor. Could that be the problem that it must be 2.2K ohms and 3K is too high? When I measure the resistance between the wiper and the chassis or one of the ends of the volume control when the radio is on, the sound clears right up (Yes, it's an odd test). As I turn the volume control up and down There's a spot past which the sound is overloaded and if I turn the volume down below that point the sound is very quiet. So I suspect a broken volume control. The carbon piece is probably cracked.
: What does everyone else think? I'll try another volume control and see if I'm right. Fortunately this radio takes a standard volume control. It's a single control with a switch. That should be easy to replace.
:
:Thanks,
:
:Dave

OK Dave, here is my guess: The volume control is the only way the diode plate of the 6Q7 (pin 4) has of getting to negative. What I think it is doing, is the plate is getteng saturated with electrons, and therefore distorts the signal. When you jumper the volume control, which you have given perfect symptons of being defective, the radio works until you remove the Ohmmeter and the diode plate saturates again. I'll bet, if you replace that volume control, you'll have a fine working radio.

Lewis

::Hello All,
:: I replaced all the paper and filter capacitors in this radio. SAMS AR-2 or 131-12. It's workng but I hear distortion as if a resistor is open. But which one? The two R11 and R12 aren't open. R13 had a broken lead. So I replaced it will a 3K resistor. Could that be the problem that it must be 2.2K ohms and 3K is too high? When I measure the resistance between the wiper and the chassis or one of the ends of the volume control when the radio is on, the sound clears right up (Yes, it's an odd test). As I turn the volume control up and down There's a spot past which the sound is overloaded and if I turn the volume down below that point the sound is very quiet. So I suspect a broken volume control. The carbon piece is probably cracked.
:: What does everyone else think? I'll try another volume control and see if I'm right. Fortunately this radio takes a standard volume control. It's a single control with a switch. That should be easy to replace.
::
::Thanks,
::
::Dave
:
:
:OK Dave, here is my guess: The volume control is the only way the diode plate of the 6Q7 (pin 4) has of getting to negative. What I think it is doing, is the plate is getteng saturated with electrons, and therefore distorts the signal. When you jumper the volume control, which you have given perfect symptons of being defective, the radio works until you remove the Ohmmeter and the diode plate saturates again. I'll bet, if you replace that volume control, you'll have a fine working radio.
:
:Lewis

Excuse the above, I hit the enter key by mistake. Change "returning to negative" to "returning to the cathode". For the newbies out there, the manufacturers put two diode plates in the tube, and it seems that everybody that designs a radio uses them in a slightly different configuration to obtian the audio and the AVC Voltage. You might want to study some radio schematics in the Resources section to see all of the ways the designers wired those two diode plates in order to accomplish exactly the same thing/
Lewis