I recieved a schematic and got my radio up and playing,(bad buffer cap & vibrator) but only on the upper portion of the dial. Cant get any local stations at 560 to about 1100 Kc's Also has a motor boating or somthing about every 200 to 300 Kc's while tuning, more at the upper end. Have tryed different tubes, no help. Any one have any idea's??

Hi,

I would check the caps in and around the oscillator stage, and check the resitor values to see that they have not deviated too far from spec. It would not hurt to check the caps around the IF stage prior to the detector also, but I believe you should find one going bad that connects from, or bypasses the oscillator section of the tunning gang.

It sounds also as if there may be another bad cap ahead of the (second)detector . You might also have a bad cap between the detector and the output, but I would look between the IF and the second detector stage.

If you have not replaced all of the paper caps, you might want to do so longevity of the repairs. If you have replaced all of the paper caps, check lead dress, solder joints, and double check to make sure everything went to the correct location.

: I recieved a schematic and got my radio up and playing,(bad buffer cap & vibrator) but only on the upper portion of the dial. Cant get any local stations at 560 to about 1100 Kc's Also has a motor boating or somthing about every 200 to 300 Kc's while tuning, more at the upper end. Have tryed different tubes, no help. Any one have any idea's??

I would go with John's suggestion. Almost all of those old paper
caps get real leaky in their old age. If questional, replace 'em.

: Hi,

:
: I would check the caps in and around the oscillator stage, and check the resitor values to see that they have not deviated too far from spec. It would not hurt to check the caps around the IF stage prior to the detector also, but I believe you should find one going bad that connects from, or bypasses the oscillator section of the tunning gang.

: It sounds also as if there may be another bad cap ahead of the (second)detector . You might also have a bad cap between the detector and the output, but I would look between the IF and the second detector stage.

: If you have not replaced all of the paper caps, you might want to do so longevity of the repairs. If you have replaced all of the paper caps, check lead dress, solder joints, and double check to make sure everything went to the correct location.

: : I recieved a schematic and got my radio up and playing,(bad buffer cap & vibrator) but only on the upper portion of the dial. Cant get any local stations at 560 to about 1100 Kc's Also has a motor boating or somthing about every 200 to 300 Kc's while tuning, more at the upper end. Have tryed different tubes, no help. Any one have any idea's??

Thank's Guys, I didn't replace all of the caps, I willgo back and check / replace them. I did notice that the screen voltage's are low(about 1/2 of spec's) Mabey one of the caps is drawing it down. plate volts are correct. : I would go with John's suggestion. Almost all of those old paper
: caps get real leaky in their old age. If questional, replace 'em.

: : Hi,

: :
: : I would check the caps in and around the oscillator stage, and check the resitor values to see that they have not deviated too far from spec. It would not hurt to check the caps around the IF stage prior to the detector also, but I believe you should find one going bad that connects from, or bypasses the oscillator section of the tunning gang.

: : It sounds also as if there may be another bad cap ahead of the (second)detector . You might also have a bad cap between the detector and the output, but I would look between the IF and the second detector stage.

: : If you have not replaced all of the paper caps, you might want to do so longevity of the repairs. If you have replaced all of the paper caps, check lead dress, solder joints, and double check to make sure everything went to the correct location.

: : : I recieved a schematic and got my radio up and playing,(bad buffer cap & vibrator) but only on the upper portion of the dial. Cant get any local stations at 560 to about 1100 Kc's Also has a motor boating or somthing about every 200 to 300 Kc's while tuning, more at the upper end. Have tryed different tubes, no help. Any one have any idea's??