Philco 90 Amps

2/11/2012 4:36:05 PMJay

I recently purchased a Philco 90 with the 2 45 tubes. In bringing it up with the variac, at about 80 volts it begins drawing millamps very fast. I changed the electrolytics, 3 paper caps, and leakly resistor. In bringing it up again, it plays with static and hum but it still draws over 4 millamps at about 90 volts. I don't know the maximum amperes it should draw. Can anyone tell me what it should be. I don't know the wattage either. If I knew the watts I could calculate the amps. I want to do a voltage check but since I am afraid to pump up the voltage, I can't take an accurate read. Any speculation why it's pulling high amps. The power transformer appears to be ok.
Thanks,
Jay

2/11/2012 6:43:41 PMMitch

:I recently purchased a Philco 90 with the 2 45 tubes. In bringing it up with the variac, at about 80 volts it begins drawing millamps very fast. I changed the electrolytics, 3 paper caps, and leakly resistor. In bringing it up again, it plays with static and hum but it still draws over 4 millamps at about 90 volts. I don't know the maximum amperes it should draw. Can anyone tell me what it should be. I don't know the wattage either. If I knew the watts I could calculate the amps. I want to do a voltage check but since I am afraid to pump up the voltage, I can't take an accurate read. Any speculation why it's pulling high amps. The power transformer appears to be ok.
:Thanks,
:Jay
:
Jay,

At eighty volts you should see miliamps even sooner though.

At 90 volts you see 0.004 amps which is 0.360 watts, this is very low to me. Do you have an amp meter measuring at the power cord of the radio from the variac?

If you changed the filter capacitors you should see a rush of current at a certain voltage, hold the voltage there and watch the current go down as the capacitors charge, then raise the voltage some more and watch the current again. You should be able to get to 110 VAC monitoring the current and then calculate the wattage.

The specification information states that if you were using #27 tubes it could draw over 50 watts.

Mitch

2/11/2012 6:50:02 PMMitch

::I recently purchased a Philco 90 with the 2 45 tubes. In bringing it up with the variac, at about 80 volts it begins drawing millamps very fast. I changed the electrolytics, 3 paper caps, and leakly resistor. In bringing it up again, it plays with static and hum but it still draws over 4 millamps at about 90 volts. I don't know the maximum amperes it should draw. Can anyone tell me what it should be. I don't know the wattage either. If I knew the watts I could calculate the amps. I want to do a voltage check but since I am afraid to pump up the voltage, I can't take an accurate read. Any speculation why it's pulling high amps. The power transformer appears to be ok.
::Thanks,
::Jay
::
:Jay,
:
:At eighty volts you should see miliamps even sooner though.
:
:At 90 volts you see 0.004 amps which is 0.360 watts, this is very low to me. Do you have an amp meter measuring at the power cord of the radio from the variac?
:
:If you changed the filter capacitors you should see a rush of current at a certain voltage, hold the voltage there and watch the current go down as the capacitors charge, then raise the voltage some more and watch the current again. You should be able to get to 110 VAC monitoring the current and then calculate the wattage.
:
:The specification information states that if you were using #27 tubes it could draw over 50 watts.
:
:Mitch
:
One more thought, if you are drawing 0.400 amps this would be 36 watts which would be fairly normal. This radio could draw as much as 60 watts at the proper operating voltage.

Mitch

2/12/2012 2:43:59 PMJay

:::I recently purchased a Philco 90 with the 2 45 tubes. In bringing it up with the variac, at about 80 volts it begins drawing millamps very fast. I changed the electrolytics, 3 paper caps, and leakly resistor. In bringing it up again, it plays with static and hum but it still draws over 4 millamps at about 90 volts. I don't know the maximum amperes it should draw. Can anyone tell me what it should be. I don't know the wattage either. If I knew the watts I could calculate the amps. I want to do a voltage check but since I am afraid to pump up the voltage, I can't take an accurate read. Any speculation why it's pulling high amps. The power transformer appears to be ok.
:::Thanks,
:::Jay
:::
::Jay,
::
::At eighty volts you should see miliamps even sooner though.
::
::At 90 volts you see 0.004 amps which is 0.360 watts, this is very low to me. Do you have an amp meter measuring at the power cord of the radio from the variac?
::
::If you changed the filter capacitors you should see a rush of current at a certain voltage, hold the voltage there and watch the current go down as the capacitors charge, then raise the voltage some more and watch the current again. You should be able to get to 110 VAC monitoring the current and then calculate the wattage.
::
::The specification information states that if you were using #27 tubes it could draw over 50 watts.
::
::Mitch
::
:One more thought, if you are drawing 0.400 amps this would be 36 watts which would be fairly normal. This radio could draw as much as 60 watts at the proper operating voltage.
:
:Mitch
:
Thanks Mitch. I will try what you suggests. I tried increasing the voltage however at a little over 90 volts it was drawing over .006 amps and the weirdest thing happened--I started losing audio and getting a lot of distortion. I guess there could be a cap problem in one of the blocks or another resistor. I guess I can take all the resistance measures. This is my first time trying to restore one of these. I might be in over my head. Jay

2/12/2012 5:32:38 PMMitch

::::I recently purchased a Philco 90 with the 2 45 tubes. In bringing it up with the variac, at about 80 volts it begins drawing millamps very fast. I changed the electrolytics, 3 paper caps, and leakly resistor. In bringing it up again, it plays with static and hum but it still draws over 4 millamps at about 90 volts. I don't know the maximum amperes it should draw. Can anyone tell me what it should be. I don't know the wattage either. If I knew the watts I could calculate the amps. I want to do a voltage check but since I am afraid to pump up the voltage, I can't take an accurate read. Any speculation why it's pulling high amps. The power transformer appears to be ok.
::::Thanks,
::::Jay
::::
:::Jay,
:::
:::At eighty volts you should see miliamps even sooner though.
:::
:::At 90 volts you see 0.004 amps which is 0.360 watts, this is very low to me. Do you have an amp meter measuring at the power cord of the radio from the variac?
:::
:::If you changed the filter capacitors you should see a rush of current at a certain voltage, hold the voltage there and watch the current go down as the capacitors charge, then raise the voltage some more and watch the current again. You should be able to get to 110 VAC monitoring the current and then calculate the wattage.
:::
:::The specification information states that if you were using #27 tubes it could draw over 50 watts.
:::
:::Mitch
:::
::One more thought, if you are drawing 0.400 amps this would be 36 watts which would be fairly normal. This radio could draw as much as 60 watts at the proper operating voltage.
::
::Mitch
::
:Thanks Mitch. I will try what you suggests. I tried increasing the voltage however at a little over 90 volts it was drawing over .006 amps and the weirdest thing happened--I started losing audio and getting a lot of distortion. I guess there could be a cap problem in one of the blocks or another resistor. I guess I can take all the resistance measures. This is my first time trying to restore one of these. I might be in over my head. Jay
:
Jay,

Post your email address or send one to me, mine is posted. I will send you some information on how to make the current measurements on these radios that is safe and accurate.

The 0.006 amps does not seem correct.

Mitch