Did you mean filament voltage is .2 - .3 volts? There may be a short in the filament circuit. The transformer should be getting warm.
Yes, I meant the filament voltage is .2-.3 volts. I must be getting old... The transformer does get warm, but not overly hot.
I forgot to say THANKS for replying in my followup to your email. I am getting old...
Did you mean filament voltage is .2 - .3 volts? There may be a short in the filament circuit. The transformer should be getting warm.
I submitted this before I was finished...if anyone knows what might be causing the power problems please give me a hollar. Thanks!
Plate voltage will be high if your tubes aren't drawing enough current. Can you test tubes? or do you have another 47? What voltage do you have between grid #1 and filament on your 47. This tube draws the most current in your radio.
Measure cathode voltage on your other tubes. If too high tubes won't draw current. Be sure volume control is turned up.
Be sure resistors and caps around you #24 ,2nd det, are ok. If bad, distortion and weak volume.
High line voltage can give higher B+ readings but not that much above.
Norm
::I have a voltage problem with an A-K 80 I am restoring. The set picks up three local station (weakly) with the volume control turned all the way up. All the plate voltages are approx. 100 volts higher than the voltage table indicates they should be, except for the oscillator, which is OK. All plate voltages are 0.2-0.3 volts but should be 2.4 volts.
:
:I submitted this before I was finished...if anyone knows what might be causing the power problems please give me a hollar. Thanks!
Thanks very much for your reply and advice. I bought a used 47 awhile back and didn't test it before I put it in the set. I tested it today and it's very weak. I'll see what happens when I find a better 47. Another lesson learned the hard way...
The cathode current appears within limits on all tubes. I ran a check on all the bypass caps and they are within tolerance. I replaced the two 8 mfd filter caps earlier, and they still test OK.
One thing I'm still having a problem with is the resistors. The type in the set are old ceramics with soldered ends; they have either one or two colors each. I don't have any data to tell me the resistance values on these type resistors, so I don't know which are good and which may be bad. If any around the 24 are bad, I don't know what to replace them with. Do you have any data on these type of resistors?
Thanks again,
Jeff
:Hi
:
: Plate voltage will be high if your tubes aren't drawing enough current. Can you test tubes? or do you have another 47? What voltage do you have between grid #1 and filament on your 47. This tube draws the most current in your radio.
:
: Measure cathode voltage on your other tubes. If too high tubes won't draw current. Be sure volume control is turned up.
:
: Be sure resistors and caps around you #24 ,2nd det, are ok. If bad, distortion and weak volume.
:
: High line voltage can give higher B+ readings but not that much above.
:
:Norm
:
:::I have a voltage problem with an A-K 80 I am restoring. The set picks up three local station (weakly) with the volume control turned all the way up. All the plate voltages are approx. 100 volts higher than the voltage table indicates they should be, except for the oscillator, which is OK. All plate voltages are 0.2-0.3 volts but should be 2.4 volts.
::
::I submitted this before I was finished...if anyone knows what might be causing the power problems please give me a hollar. Thanks!
You will find what you need near top of the Atwater Kent listing, Tubular Resistors. The schematic is also available.
http://www.nostalgiaair.org/Riders/A-K.htm
Most of your tubes should draw a few ma of current. A #47 draws around 37 ma. Since your 47 is weak it's probably drawing much less causing voltage to be high.
Norm
:Norm,
:
:Thanks very much for your reply and advice. I bought a used 47 awhile back and didn't test it before I put it in the set. I tested it today and it's very weak. I'll see what happens when I find a better 47. Another lesson learned the hard way...
:
:The cathode current appears within limits on all tubes. I ran a check on all the bypass caps and they are within tolerance. I replaced the two 8 mfd filter caps earlier, and they still test OK.
:
:One thing I'm still having a problem with is the resistors. The type in the set are old ceramics with soldered ends; they have either one or two colors each. I don't have any data to tell me the resistance values on these type resistors, so I don't know which are good and which may be bad. If any around the 24 are bad, I don't know what to replace them with. Do you have any data on these type of resistors?
:
:Thanks again,
:
:Jeff
:
:
::Hi
::
:: Plate voltage will be high if your tubes aren't drawing enough current. Can you test tubes? or do you have another 47? What voltage do you have between grid #1 and filament on your 47. This tube draws the most current in your radio.
::
:: Measure cathode voltage on your other tubes. If too high tubes won't draw current. Be sure volume control is turned up.
::
:: Be sure resistors and caps around you #24 ,2nd det, are ok. If bad, distortion and weak volume.
::
:: High line voltage can give higher B+ readings but not that much above.
::
::Norm
::
::::I have a voltage problem with an A-K 80 I am restoring. The set picks up three local station (weakly) with the volume control turned all the way up. All the plate voltages are approx. 100 volts higher than the voltage table indicates they should be, except for the oscillator, which is OK. All plate voltages are 0.2-0.3 volts but should be 2.4 volts.
:::
:::I submitted this before I was finished...if anyone knows what might be causing the power problems please give me a hollar. Thanks!
I found the resistor data. Again, thanks for the advice!
Jeff
Jeff
:
: You will find what you need near top of the Atwater Kent listing, Tubular Resistors. The schematic is also available.
:
:http://www.nostalgiaair.org/Riders/A-K.htm
:
: Most of your tubes should draw a few ma of current. A #47 draws around 37 ma. Since your 47 is weak it's probably drawing much less causing voltage to be high.
:
:Norm
:
::Norm,
::
::Thanks very much for your reply and advice. I bought a used 47 awhile back and didn't test it before I put it in the set. I tested it today and it's very weak. I'll see what happens when I find a better 47. Another lesson learned the hard way...
::
::The cathode current appears within limits on all tubes. I ran a check on all the bypass caps and they are within tolerance. I replaced the two 8 mfd filter caps earlier, and they still test OK.
::
::One thing I'm still having a problem with is the resistors. The type in the set are old ceramics with soldered ends; they have either one or two colors each. I don't have any data to tell me the resistance values on these type resistors, so I don't know which are good and which may be bad. If any around the 24 are bad, I don't know what to replace them with. Do you have any data on these type of resistors?
::
::Thanks again,
::
::Jeff
::
::
:::Hi
:::
::: Plate voltage will be high if your tubes aren't drawing enough current. Can you test tubes? or do you have another 47? What voltage do you have between grid #1 and filament on your 47. This tube draws the most current in your radio.
:::
::: Measure cathode voltage on your other tubes. If too high tubes won't draw current. Be sure volume control is turned up.
:::
::: Be sure resistors and caps around you #24 ,2nd det, are ok. If bad, distortion and weak volume.
:::
::: High line voltage can give higher B+ readings but not that much above.
:::
:::Norm
:::
:::::I have a voltage problem with an A-K 80 I am restoring. The set picks up three local station (weakly) with the volume control turned all the way up. All the plate voltages are approx. 100 volts higher than the voltage table indicates they should be, except for the oscillator, which is OK. All plate voltages are 0.2-0.3 volts but should be 2.4 volts.
::::
::::I submitted this before I was finished...if anyone knows what might be causing the power problems please give me a hollar. Thanks!