simplex model R "AC" Schematic filer cap polarity?
2/8/2008 3:32:28 PMsean(59129:0)
Hello I am trying to replace the 2 filter caps that are marked 4 uf. I cant seem to determine what polarity the common wire between the two caps is supposed to be. My guess would be Neg since it goes to the filament string which is also the 80 tubes cathode. Am I right?
I replaced some of the capacitors and noticed that the 80 tube had blue around the filaments and got really hot, so that tells me something is drawing too much current. I forgot to hookup the ground lead of the 004 cap off the 47, would this cause the 80 tube to overheat?
I was about to replace the 325 ohm resistor because I thought it was supposed to be 300mohms but there are 2 model r schematics. The one my radio matches is page 8-2, bottom schematic. "model r sereal 175001 and up. Yep it sure helps to be looking at the right schematic!!!
I replaced some of the capacitors and noticed that the 80 tube had blue around the filaments and got really hot, so that tells me something is drawing too much current. I forgot to hookup the ground lead of the 004 cap off the 47, would this cause the 80 tube to overheat?
I was about to replace the 325 ohm resistor because I thought it was supposed to be 300mohms but there are 2 model r schematics. The one my radio matches is page 8-2, bottom schematic. "model r sereal 175001 and up. Yep it sure helps to be looking at the right schematic!!!
2/8/2008 3:49:32 PMsean(59130:59129)
:also one of the caps (I used 2 ten microfarads for replacement) of the 4 uf caps) gets hot when I turn on the set. I put a volt meter across it and it says negative 60 volts? Is this cap backwards or shorted out?
:Hello I am trying to replace the 2 filter caps that are marked 4 uf. I cant seem to determine what polarity the common wire between the two caps is supposed to be. My guess would be Neg since it goes to the filament string which is also the 80 tubes cathode. Am I right?
: I replaced some of the capacitors and noticed that the 80 tube had blue around the filaments and got really hot, so that tells me something is drawing too much current. I forgot to hookup the ground lead of the 004 cap off the 47, would this cause the 80 tube to overheat?
: I was about to replace the 325 ohm resistor because I thought it was supposed to be 300mohms but there are 2 model r schematics. The one my radio matches is page 8-2, bottom schematic. "model r sereal 175001 and up. Yep it sure helps to be looking at the right schematic!!!
:Hello I am trying to replace the 2 filter caps that are marked 4 uf. I cant seem to determine what polarity the common wire between the two caps is supposed to be. My guess would be Neg since it goes to the filament string which is also the 80 tubes cathode. Am I right?
: I replaced some of the capacitors and noticed that the 80 tube had blue around the filaments and got really hot, so that tells me something is drawing too much current. I forgot to hookup the ground lead of the 004 cap off the 47, would this cause the 80 tube to overheat?
: I was about to replace the 325 ohm resistor because I thought it was supposed to be 300mohms but there are 2 model r schematics. The one my radio matches is page 8-2, bottom schematic. "model r sereal 175001 and up. Yep it sure helps to be looking at the right schematic!!!
2/8/2008 4:59:54 PMThomas Dermody(59133:59130)
The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
T.
2/9/2008 12:41:55 AMplanigan(59150:59133)
sean, you are increasing the mfd by 150% by using 10mfd. I would suggest you use 5mfd caps. The higher mfd will put stress on the 80. PL
:The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
:
:Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
:
:T.
2/9/2008 2:52:39 PMThomas Dermody(59173:59150)
Planigan, the #80 tube can handle a lot more than 10 MFD as an input capacitance. I've used as much as 50 MFD, though 40 is probably where you should max. at.
T.
2/9/2008 1:26:12 AMsean(59152:59133)
:Ok translation, I should not stop working on radios so I wont forget how to replace caps. Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
:The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
:
:Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
:
:T.
:The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
:
:Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
:
:T.
2/9/2008 6:23:58 AMsean(59154:59152)
:Ok got the caps replaced and whatduya know it works again, thanks. Now one more question. I have a .1 uf cap on this thing I wanna replace, but it has a metal clip around it that goes most of the way around the body of the cap. The cap is the usuall axial lead type wax filled paper one. There is a wire soldered to this clip that goes to the 57 or 58 tube pin 4. I dont know what to do with this clip once I replace the cap since new caps are a lot smaller. Is this wire a feedback wire like in the philco model 80? I would guess it needs it but how do I keep this wire clip in use with a smaller cap size due to newer cap
::Ok translation, I should not stop working on radios so I wont forget how to replace caps. Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
::The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
::
::Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
::
::T.
::Ok translation, I should not stop working on radios so I wont forget how to replace caps. Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
::The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
::
::Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
::
::T.
2/9/2008 9:59:48 PMSEAN(59179:59154)
:OK update, the cap with the clip all the way around it is a .1 uf. It is connected from pin 3 (g2) to chassis ground. The wire that is soldered to the clip around the outside of the cap goes to pin 4 of the 58 tube. Do I just wrap the wire around the new .1 up cap, or is this kinda important to get it exactly hooked up like the original?
::Ok got the caps replaced and whatduya know it works again, thanks. Now one more question. I have a .1 uf cap on this thing I wanna replace, but it has a metal clip around it that goes most of the way around the body of the cap. The cap is the usuall axial lead type wax filled paper one. There is a wire soldered to this clip that goes to the 57 or 58 tube pin 4. I dont know what to do with this clip once I replace the cap since new caps are a lot smaller. Is this wire a feedback wire like in the philco model 80? I would guess it needs it but how do I keep this wire clip in use with a smaller cap size due to newer cap
:::Ok translation, I should not stop working on radios so I wont forget how to replace caps. Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
:::The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
:::
:::Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
:::
:::T.
::Ok got the caps replaced and whatduya know it works again, thanks. Now one more question. I have a .1 uf cap on this thing I wanna replace, but it has a metal clip around it that goes most of the way around the body of the cap. The cap is the usuall axial lead type wax filled paper one. There is a wire soldered to this clip that goes to the 57 or 58 tube pin 4. I dont know what to do with this clip once I replace the cap since new caps are a lot smaller. Is this wire a feedback wire like in the philco model 80? I would guess it needs it but how do I keep this wire clip in use with a smaller cap size due to newer cap
:::Ok translation, I should not stop working on radios so I wont forget how to replace caps. Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
:::The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
:::
:::Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
:::
:::T.
2/10/2008 1:17:05 AMsean(59194:59179)
:Hello again. I still dont know what to do with this one cap. Ive never seen a clip or clamp around a cap that isnt for support of the cap. Well I guess Im gonna take off the cap, and just cut the wire. I dont know what else to do
::OK update, the cap with the clip all the way around it is a .1 uf. It is connected from pin 3 (g2) to chassis ground. The wire that is soldered to the clip around the outside of the cap goes to pin 4 of the 58 tube. Do I just wrap the wire around the new .1 up cap, or is this kinda important to get it exactly hooked up like the original?
:::Ok got the caps replaced and whatduya know it works again, thanks. Now one more question. I have a .1 uf cap on this thing I wanna replace, but it has a metal clip around it that goes most of the way around the body of the cap. The cap is the usuall axial lead type wax filled paper one. There is a wire soldered to this clip that goes to the 57 or 58 tube pin 4. I dont know what to do with this clip once I replace the cap since new caps are a lot smaller. Is this wire a feedback wire like in the philco model 80? I would guess it needs it but how do I keep this wire clip in use with a smaller cap size due to newer cap
::::Ok translation, I should not stop working on radios so I wont forget how to replace caps. Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
::::The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
::::
::::Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
::::
::::T.
::OK update, the cap with the clip all the way around it is a .1 uf. It is connected from pin 3 (g2) to chassis ground. The wire that is soldered to the clip around the outside of the cap goes to pin 4 of the 58 tube. Do I just wrap the wire around the new .1 up cap, or is this kinda important to get it exactly hooked up like the original?
:::Ok got the caps replaced and whatduya know it works again, thanks. Now one more question. I have a .1 uf cap on this thing I wanna replace, but it has a metal clip around it that goes most of the way around the body of the cap. The cap is the usuall axial lead type wax filled paper one. There is a wire soldered to this clip that goes to the 57 or 58 tube pin 4. I dont know what to do with this clip once I replace the cap since new caps are a lot smaller. Is this wire a feedback wire like in the philco model 80? I would guess it needs it but how do I keep this wire clip in use with a smaller cap size due to newer cap
::::Ok translation, I should not stop working on radios so I wont forget how to replace caps. Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
::::The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
::::
::::Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
::::
::::T.
2/11/2008 2:35:36 PMSteve(59261:59194)
Sean,
I was just reading thru your problem with the old cap. One of the things I find with my old RCA victrola 612V3 is that there is unusual things done long ago that have long since disolved into the ether. I have also found, try it without, because most of these circuits aren't that critical. Sounds like some type filtering aftermarket fix by the manufacturer. Your guess is sound grasshopper.
Regards
Steve
I was just reading thru your problem with the old cap. One of the things I find with my old RCA victrola 612V3 is that there is unusual things done long ago that have long since disolved into the ether. I have also found, try it without, because most of these circuits aren't that critical. Sounds like some type filtering aftermarket fix by the manufacturer. Your guess is sound grasshopper.
Regards
Steve
2/11/2008 5:12:47 PMEdd(59270:59261)
I saw you hanging….stymied…. there also :
<" Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
">
On the typical solid state diode, the band / ring / dot referenced lead is the CATHODE and it would be the source of your + DC voltage if fed with raw AC into its other ANODE lead. 
I’m looking at the two schematics on the page….. and you said that the top one was your "R" series unit… I do see the handling of the G2 ad G3 circuitry of the “Simple” little receiver and with nothing varying from the norm in the bypassing / decoupling actions of those .1ufd units.
Some manufacturers larger sized capacitors did sometimes have mounting straps around them, particularly, if used in a mobile environment like the military, where their mass , if left floating could result in vibrationally broken leads. I assume that they had the strap grounded with a screw or rivet and possibly the lead that would have went to ground…was soldered to that strap ?
The only other application special to a cap of that mechanical dimensions that I can remember is where there is a coil wound around a portion of the outside of the cap with several turns of wire, and then connected to one end of the cap with the other end of the coil wire going to ground.
That just mentioned cap is usually in the order of decimal 001ufd and the series inductor made with the wire results in a series L/C trap coil that shunts potentially bothersome low frequency signals from NAVTEK, GWEN and NAVBEACON transmissions .
I don’t think that you have that situation on your chassis, with a series RF attenuation trap built as I mentioned.
As well, your low mechanical mass replacement caps definitely should not need mechanical support.
73's de Edd
:Sean,
:I was just reading thru your problem with the old cap. One of the things I find with my old RCA victrola 612V3 is that there is unusual things done long ago that have long since disolved into the ether. I have also found, try it without, because most of these circuits aren't that critical. Sounds like some type filtering aftermarket fix by the manufacturer. Your guess is sound grasshopper.
:Regards
:Steve
2/11/2008 7:09:07 PMsean(59283:59270)
:My schematic is the one that is for the "model R" with the serial above 175001. My serial is 182051. I made the mistake of looking at the wrong schematic the first time and almost replaced a whole bunch of resistors for being out of tolerance. Yes, the metal band I am talking about is not attached to anything. Just a wire soldered to it that goes to the Grid 3 or pin 4 of the 58 tube. The cap itself goes from pin 3 of the 58 tube to Grid 2 to ground.
:
:
:
:
:
:I saw you hanging….stymied…. there also :
:
:
:
:<" Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
:">
:
:
:On the typical solid state diode, the band / ring / dot referenced lead is the CATHODE and it would be the source of your + DC voltage if fed with raw AC into its other ANODE lead.
:
:
:
:
:
:
:
:I’m looking at the two schematics on the page….. and you said that the top one was your "R" series unit… I do see the handling of the G2 ad G3 circuitry of the “Simple” little receiver and with nothing varying from the norm in the bypassing / decoupling actions of those .1ufd units.
:
: Some manufacturers larger sized capacitors did sometimes have mounting straps around them, particularly, if used in a mobile environment like the military, where their mass , if left floating could result in vibrationally broken leads. I assume that they had the strap grounded with a screw or rivet and possibly the lead that would have went to ground…was soldered to that strap ?
:The only other application special to a cap of that mechanical dimensions that I can remember is where there is a coil wound around a portion of the outside of the cap with several turns of wire, and then connected to one end of the cap with the other end of the coil wire going to ground.
:That just mentioned cap is usually in the order of decimal 001ufd and the series inductor made with the wire results in a series L/C trap coil that shunts potentially bothersome low frequency signals from NAVTEK, GWEN and NAVBEACON transmissions .
:
:I don’t think that you have that situation on your chassis, with a series RF attenuation trap built as I mentioned.
:As well, your low mechanical mass replacement caps definitely should not need mechanical support.
:
:
:
:73's de Edd
:
:
:
:
:
:
:
:
:
:
:
::Sean,
::I was just reading thru your problem with the old cap. One of the things I find with my old RCA victrola 612V3 is that there is unusual things done long ago that have long since disolved into the ether. I have also found, try it without, because most of these circuits aren't that critical. Sounds like some type filtering aftermarket fix by the manufacturer. Your guess is sound grasshopper.
::Regards
::Steve
:
:
:
:
:
:I saw you hanging….stymied…. there also :
:
:
:
:<" Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
:">
:
:
:On the typical solid state diode, the band / ring / dot referenced lead is the CATHODE and it would be the source of your + DC voltage if fed with raw AC into its other ANODE lead.
:
:
:
:
:
:
:
:I’m looking at the two schematics on the page….. and you said that the top one was your "R" series unit… I do see the handling of the G2 ad G3 circuitry of the “Simple” little receiver and with nothing varying from the norm in the bypassing / decoupling actions of those .1ufd units.
:
: Some manufacturers larger sized capacitors did sometimes have mounting straps around them, particularly, if used in a mobile environment like the military, where their mass , if left floating could result in vibrationally broken leads. I assume that they had the strap grounded with a screw or rivet and possibly the lead that would have went to ground…was soldered to that strap ?
:The only other application special to a cap of that mechanical dimensions that I can remember is where there is a coil wound around a portion of the outside of the cap with several turns of wire, and then connected to one end of the cap with the other end of the coil wire going to ground.
:That just mentioned cap is usually in the order of decimal 001ufd and the series inductor made with the wire results in a series L/C trap coil that shunts potentially bothersome low frequency signals from NAVTEK, GWEN and NAVBEACON transmissions .
:
:I don’t think that you have that situation on your chassis, with a series RF attenuation trap built as I mentioned.
:As well, your low mechanical mass replacement caps definitely should not need mechanical support.
:
:
:
:73's de Edd
:
:
:
:
:
:
:
:
:
:
:
::Sean,
::I was just reading thru your problem with the old cap. One of the things I find with my old RCA victrola 612V3 is that there is unusual things done long ago that have long since disolved into the ether. I have also found, try it without, because most of these circuits aren't that critical. Sounds like some type filtering aftermarket fix by the manufacturer. Your guess is sound grasshopper.
::Regards
::Steve
2/12/2008 6:10:12 PMSteve(59330:59283)
OOOOPPPPPSSSS!!!!!
Good thing I've never done that.
Oh well
Steve
Good thing I've never done that.
Oh well
Steve
2/12/2008 9:21:20 PMThomas Dermody(59341:59152)
The cathode IS the negative part of just about anything. The cathode of the rectifier in your set emits electrons, and is negative. It all depends on which way you look at it. Traditionally people think of things as flowing from positive to negative. However, that just isn't so. Actually what goes on in your set is this: The rectifier serves as a one way valve. It doesn't matter where it is put as long as it's somewhere in the circuit. For a full wave center tap type circuit you need two rectifiers (diodes). To save space and money, the rectifiers are put into one envelope. You could either have two cathodes (requiring two separate filaments in filamentary rectifiers, which also requires two extra pins), and one plate, or have two plates and one cathode (or you could have two plates and two cathodes). The two plates and one cathode set-up is simplest and cheapest. As it is set up, electrons start at the center tap of the radio. They flow through various resistors and chokes to the cathodes of all of the tubes of the radio. They then flow through all of the tubes in the radio (from cathode to plate). The electrons leave the plates of all of the tubes in the radio and go through various resistors and coils. From the resistors and coils they go to the cathode of the rectifier. The electrons are then emitted from the cathode of the rectifier to its plates, whichever one happens to be positive. ....So you see, with respect to the plates of the rectifier, the cathode IS negative. However, since there is a lot of resistance between the rectifier cathode and the center tap of the transformer, the rectifier cathode is a lot more positive than the transformer center tap. It still is negative with respect to the plates. Electricity wouldn't flow if it was positive with respect to the plates, which is exactly how it rectifies. If you were to have only one cathode and one plate (such as a 35Z5), electricity would only flow through the rectifier whenever the cathode was negative with respect to the plate. The #80 rectifier, and its relatives, is a full wave type rectifier. Look at the schematic and study it. Notice that the high voltage winding of the transformer has a center tap. Each half of the transformer winding is out of phase with the other. When one end of the winding is positive with respect to the center tap, the other half is negative with respect to the center tap. The cathode of the rectifier is alternately sending electrons to one plate and then to another.
Hmmmm....I'm getting tired, and I'm not quite sure where I"m going anymore. Hope this helps.
T.
::Ok translation, I should not stop working on radios so I wont forget how to replace caps. Ok I guess Im rusty at this but solid state diodes, isnt the cathode the negative and the anode positive?
::The rectifier cathode is always the most positive part of the set. Both of the electrolytics' positives should go to the rectifier cathode. One negative should go on one side of the field coil, and the other goes to the other side of the field coil, as indicated in the schematic.
::
::Start with fresh electrolytics. It is possible that you ruined the ones you are using currently. They cannot be installed backwards.
::
::T.