Chris
The two caps, one before the choke/reactor, the other after were originally paper capacitors which didn't really have a polarity. If you are replacing them with electrolytic caps, then polarity does make a difference. The pluses on the two caps go to filament of the 80 rectifier (pin 1 or 4). The minus on the first cap goes to the centertap of the high voltage winding. The minus on the second cap goes to the end winding lead of the choke/reactor.
Radiodoc
:So I'm restoring a Radiola 80 and having the damndest time figuring out the capacitor block. You can see the schematic on this site, but the schematic doesn't list what side is + and what side is - for some of the caps in the block. I did a voltmeter test and I was getting negative voltage from one of the leads going to the field coil so I figured put the cap - side to that but the cap gets super hot. So I could easily flip it but then it seems the cap would be running in series with another capacitor in the circuit and that doesn't make a ton of sense to me. Anyone have experience doing this cap blocks and can help me out?
:
:Chris
CW
:Chris,
:
:The two caps, one before the choke/reactor, the other after were originally paper capacitors which didn't really have a polarity. If you are replacing them with electrolytic caps, then polarity does make a difference. The pluses on the two caps go to filament of the 80 rectifier (pin 1 or 4). The minus on the first cap goes to the centertap of the high voltage winding. The minus on the second cap goes to the end winding lead of the choke/reactor.
:
:Radiodoc
:
:
::So I'm restoring a Radiola 80 and having the damndest time figuring out the capacitor block. You can see the schematic on this site, but the schematic doesn't list what side is + and what side is - for some of the caps in the block. I did a voltmeter test and I was getting negative voltage from one of the leads going to the field coil so I figured put the cap - side to that but the cap gets super hot. So I could easily flip it but then it seems the cap would be running in series with another capacitor in the circuit and that doesn't make a ton of sense to me. Anyone have experience doing this cap blocks and can help me out?
::
::Chris
Make sure the cap are rated for 450 volts or better.
Radiodoc
:Man, I thought that's what I did but I'll have to check back tonight. Maybe I mixed something up. Give me a radio from the mid30s-60s and I'm good to go, older ones I always mess em up!
:
:CW
:
::Chris,
::
::The two caps, one before the choke/reactor, the other after were originally paper capacitors which didn't really have a polarity. If you are replacing them with electrolytic caps, then polarity does make a difference. The pluses on the two caps go to filament of the 80 rectifier (pin 1 or 4). The minus on the first cap goes to the centertap of the high voltage winding. The minus on the second cap goes to the end winding lead of the choke/reactor.
::
::Radiodoc
::
::
:::So I'm restoring a Radiola 80 and having the damndest time figuring out the capacitor block. You can see the schematic on this site, but the schematic doesn't list what side is + and what side is - for some of the caps in the block. I did a voltmeter test and I was getting negative voltage from one of the leads going to the field coil so I figured put the cap - side to that but the cap gets super hot. So I could easily flip it but then it seems the cap would be running in series with another capacitor in the circuit and that doesn't make a ton of sense to me. Anyone have experience doing this cap blocks and can help me out?
:::
:::Chris
The second cap, also 10mfd 450v has the + side to the filament and - to the 385 ohm side of the choke/reactor (the resistances are all measuring ok)which is also attached to the center tap of the high voltage.
The 3rd cap is again 10mfd 450V, + side to the filament and - to the 15 ohm side of the choke. This one however, gets super hot and I'm sure it'll blow if I let it go any longer than 10 seconds.
Someone had monkeyed around with this set at one time as the output transformer has already been replaced with a different one.
I'm wondering if I need higher than 450V caps? Maybe I'm alright but the voltage is just too high? I know when I measured the output on the high voltage it was closer to 600V.
:Chris,
:
:The two caps, one before the choke/reactor, the other after were originally paper capacitors which didn't really have a polarity. If you are replacing them with electrolytic caps, then polarity does make a difference. The pluses on the two caps go to filament of the 80 rectifier (pin 1 or 4). The minus on the first cap goes to the centertap of the high voltage winding. The minus on the second cap goes to the end winding lead of the choke/reactor.
:
:Radiodoc
:
:
::So I'm restoring a Radiola 80 and having the damndest time figuring out the capacitor block. You can see the schematic on this site, but the schematic doesn't list what side is + and what side is - for some of the caps in the block. I did a voltmeter test and I was getting negative voltage from one of the leads going to the field coil so I figured put the cap - side to that but the cap gets super hot. So I could easily flip it but then it seems the cap would be running in series with another capacitor in the circuit and that doesn't make a ton of sense to me. Anyone have experience doing this cap blocks and can help me out?
::
::Chris
If you measured DC 600 volts between the 80 filament and centertap, then the rating of the 450 volt caps would be exceeded. You may try putting two 450 volt caps in series and see if they get warm. Remember with two same capacitance value caps in series, the total capacitance will be half. If you decide to leave the caps in, then resistors will have to be placed in parallel with each cap across the B+ to balance the voltage across each cap.
Radiodoc
:OK I checked it out again and I do have it wired as you said. I have one 10 mfd 450v cap (Smallest I have)going from the filament to ground on the 80. That one seems fine. When I got the set someone had, long ago, already replaced that part.
:
:The second cap, also 10mfd 450v has the + side to the filament and - to the 385 ohm side of the choke/reactor (the resistances are all measuring ok)which is also attached to the center tap of the high voltage.
:
:The 3rd cap is again 10mfd 450V, + side to the filament and - to the 15 ohm side of the choke. This one however, gets super hot and I'm sure it'll blow if I let it go any longer than 10 seconds.
:
:Someone had monkeyed around with this set at one time as the output transformer has already been replaced with a different one.
:
:I'm wondering if I need higher than 450V caps? Maybe I'm alright but the voltage is just too high? I know when I measured the output on the high voltage it was closer to 600V.
:
::Chris,
::
::The two caps, one before the choke/reactor, the other after were originally paper capacitors which didn't really have a polarity. If you are replacing them with electrolytic caps, then polarity does make a difference. The pluses on the two caps go to filament of the 80 rectifier (pin 1 or 4). The minus on the first cap goes to the centertap of the high voltage winding. The minus on the second cap goes to the end winding lead of the choke/reactor.
::
::Radiodoc
::
::
:::So I'm restoring a Radiola 80 and having the damndest time figuring out the capacitor block. You can see the schematic on this site, but the schematic doesn't list what side is + and what side is - for some of the caps in the block. I did a voltmeter test and I was getting negative voltage from one of the leads going to the field coil so I figured put the cap - side to that but the cap gets super hot. So I could easily flip it but then it seems the cap would be running in series with another capacitor in the circuit and that doesn't make a ton of sense to me. Anyone have experience doing this cap blocks and can help me out?
:::
:::Chris
Also Chris,
If the radio has the original transformer, you may want to check and make sure the highest voltage primary connection is being used. That is the 120 volt connection instead of the 110 volt one.
Radiodoc
:::
:::
::::So I'm restoring a Radiola 80 and having the damndest time figuring out the capacitor block. You can see the schematic on this site, but the schematic doesn't list what side is + and what side is - for some of the caps in the block. I did a voltmeter test and I was getting negative voltage from one of the leads going to the field coil so I figured put the cap - side to that but the cap gets super hot. So I could easily flip it but then it seems the cap would be running in series with another capacitor in the circuit and that doesn't make a ton of sense to me. Anyone have experience doing this cap blocks and can help me out?
::::
::::Chris