After running my RCA AA5 receiver for a few hours, I started to hear this snapping sound. Apparently one of the wax caps was breaking down. I think the unit connected to the plate of the 50C5 output tube shorted, taking the 33 ohm, 1 watt resistor in the power supply with it.
I bow to all!!
Now does anyone have a few 33 ohm , 1 watt carbons to trade for any other parts? I have to look for a local parts supplier in Marlborough, Mass that I can walk into and buy parts over the counter (I know - good luck - not like the old days).
Lou
Do you have a local Radio Shack? The resistor should cost less than a stamp. Mouser also sells parts without a min.
I used to travel to DEC in your area while working for National Semiconductor.
Norm
:I concede!!
:
:After running my RCA AA5 receiver for a few hours, I started to hear this snapping sound. Apparently one of the wax caps was breaking down. I think the unit connected to the plate of the 50C5 output tube shorted, taking the 33 ohm, 1 watt resistor in the power supply with it.
:
: I bow to all!!
:
:Now does anyone have a few 33 ohm , 1 watt carbons to trade for any other parts? I have to look for a local parts supplier in Marlborough, Mass that I can walk into and buy parts over the counter (I know - good luck - not like the old days).
:
:Lou
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I am also investigating an ARROW electronics distributor in the area.
PS: My AA5 has a 0.015 uF cap on the plate of the 50C5.Looks like audio tailoring. What does this cap do? Will a 0.01 uF replacement suffice?
Thanks
Lou
:Lou
:
: Do you have a local Radio Shack? The resistor should cost less than a stamp. Mouser also sells parts without a min.
:
: I used to travel to DEC in your area while working for National Semiconductor.
:
:Norm
:
::I concede!!
::
::After running my RCA AA5 receiver for a few hours, I started to hear this snapping sound. Apparently one of the wax caps was breaking down. I think the unit connected to the plate of the 50C5 output tube shorted, taking the 33 ohm, 1 watt resistor in the power supply with it.
::
:: I bow to all!!
::
::Now does anyone have a few 33 ohm , 1 watt carbons to trade for any other parts? I have to look for a local parts supplier in Marlborough, Mass that I can walk into and buy parts over the counter (I know - good luck - not like the old days).
::
::Lou
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Cap at plate of the output tube reduces high frequency response and may prevent unwanted oscillation. A lower cap value, .01 in place of .015 mf, will increase high frequency response. Should be ok.
Norm
:Thanks Norm
:
:I am also investigating an ARROW electronics distributor in the area.
:
:PS: My AA5 has a 0.015 uF cap on the plate of the 50C5.Looks like audio tailoring. What does this cap do? Will a 0.01 uF replacement suffice?
:
:Thanks
:Lou
:
:
::Lou
::
:: Do you have a local Radio Shack? The resistor should cost less than a stamp. Mouser also sells parts without a min.
::
:: I used to travel to DEC in your area while working for National Semiconductor.
::
::Norm
::
:::I concede!!
:::
:::After running my RCA AA5 receiver for a few hours, I started to hear this snapping sound. Apparently one of the wax caps was breaking down. I think the unit connected to the plate of the 50C5 output tube shorted, taking the 33 ohm, 1 watt resistor in the power supply with it.
:::
::: I bow to all!!
:::
:::Now does anyone have a few 33 ohm , 1 watt carbons to trade for any other parts? I have to look for a local parts supplier in Marlborough, Mass that I can walk into and buy parts over the counter (I know - good luck - not like the old days).
:::
:::Lou
:::
:::
:::
::
::
:
:
:Lou
:
: Cap at plate of the output tube reduces high frequency response and may prevent unwanted oscillation. A lower cap value, .01 in place of .015 mf, will increase high frequency response. Should be ok.
:
:Norm
:
::Thanks Norm
::
::I am also investigating an ARROW electronics distributor in the area.
::
::PS: My AA5 has a 0.015 uF cap on the plate of the 50C5.Looks like audio tailoring. What does this cap do? Will a 0.01 uF replacement suffice?
::
::Thanks
::Lou
::
::
:::Lou
:::
::: Do you have a local Radio Shack? The resistor should cost less than a stamp. Mouser also sells parts without a min.
:::
::: I used to travel to DEC in your area while working for National Semiconductor.
:::
:::Norm
:::
::::I concede!!
::::
::::After running my RCA AA5 receiver for a few hours, I started to hear this snapping sound. Apparently one of the wax caps was breaking down. I think the unit connected to the plate of the 50C5 output tube shorted, taking the 33 ohm, 1 watt resistor in the power supply with it.
::::
:::: I bow to all!!
::::
::::Now does anyone have a few 33 ohm , 1 watt carbons to trade for any other parts? I have to look for a local parts supplier in Marlborough, Mass that I can walk into and buy parts over the counter (I know - good luck - not like the old days).
::::
::::Lou
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:
Lou from Lew
If I remember correctly, that resistor is necessary only when the radio is turned off long enough for the filter caps to discharge, but not long enough for the filaments to cool. Turning the radio back on at the right (or wrong) time could zap the pilot light, or worse the rectifier tube as the current surge tries to recharge the filters and work the radio at the same time. Some radios don't even have that resistor. I guess they were built by people who also sole rectifier tubes.
Lewis
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Correction---change sole to sold.
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Tubes at one time was pretty big business. My supplier would every so often make me various 'good' deals on certain ones. I remember some good deals on sets of tubes for AA5's.
Clifton
:::This cap can see high voltages. Don't use anything less than what was originally there. 600 volt minimum woiuld be best.
:::
::::Lou
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:::: Cap at plate of the output tube reduces high frequency response and may prevent unwanted oscillation. A lower cap value, .01 in place of .015 mf, will increase high frequency response. Should be ok.
::::
::::Norm
::::
:::::Thanks Norm
:::::
:::::I am also investigating an ARROW electronics distributor in the area.
:::::
:::::PS: My AA5 has a 0.015 uF cap on the plate of the 50C5.Looks like audio tailoring. What does this cap do? Will a 0.01 uF replacement suffice?
:::::
:::::Thanks
:::::Lou
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:::::
::::::Lou
::::::
:::::: Do you have a local Radio Shack? The resistor should cost less than a stamp. Mouser also sells parts without a min.
::::::
:::::: I used to travel to DEC in your area while working for National Semiconductor.
::::::
::::::Norm
::::::
:::::::I concede!!
:::::::
:::::::After running my RCA AA5 receiver for a few hours, I started to hear this snapping sound. Apparently one of the wax caps was breaking down. I think the unit connected to the plate of the 50C5 output tube shorted, taking the 33 ohm, 1 watt resistor in the power supply with it.
:::::::
::::::: I bow to all!!
:::::::
:::::::Now does anyone have a few 33 ohm , 1 watt carbons to trade for any other parts? I have to look for a local parts supplier in Marlborough, Mass that I can walk into and buy parts over the counter (I know - good luck - not like the old days).
:::::::
:::::::Lou
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::
::
::Lou from Lew
::If I remember correctly, that resistor is necessary only when the radio is turned off long enough for the filter caps to discharge, but not long enough for the filaments to cool. Turning the radio back on at the right (or wrong) time could zap the pilot light, or worse the rectifier tube as the current surge tries to recharge the filters and work the radio at the same time. Some radios don't even have that resistor. I guess they were built by people who also sole rectifier tubes.
::Lewis
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:Correction---change sole to sold.
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