I am new to this site and just exploring tube radio hobby and enjoyment. Just acquired EMUD Rekord Senior 60 over 4th July weekend, radio is beauity, blode wood cabinet is almost new looking. Chasis is rust free and radio seems have all original part. The radio showed no sign of life when plugged in. Checked fuse by input xformer, was blown so replaced with 1.5A 250V Radio Shack. The radio lit up like xmas tree including two bulbs for dial glass. But no sound of any kind. Looking for schematic and any help with bringing this radio to life.

Thanks, Vinod

Here's your Emud info and I will get you started on it, without even having to pull the chassis.

Initially, we can confirm that the fuse is intact, since you have filaments and pilot lamps.

Now, locate the AF output tube. . .EL84 . . .pull it and note the missing pins gap and then start a clock wise count, with the first pin being pin number 9 and then 8 and then 7. . . .and thats it, with you now making a mark on the chassis beside pin numbers 9 and 7. replace the tube in its socket but leave it not fully seated such that there is about a 3-4 mm gap so that a meter probe can then be able to reach in to touch a pin to take a measurement.

Now, you get the set plugged in and its tubes glowing, take DC metering in hand and chassis ground the negative meter probe and use the + probe to take a measurement of the main B+ (I highlighted in RED, on the mark-up schema.) which ends up at pin 7 BLUE buss of that EL84 tube.

We are hoping for ~260-270 VDC B+. . . if there, GOOD, then you move over to the marked pin 9 and see what voltage is there, if low, or nothing suspect the YELLOW BOX marked up R39 as being bad, therefore not getting any sub B+ to the EL84's screen grid. . .or MORE IMPORTANTLY, the rest of the sets voltage supply, as is being depicted with the FUSCIA arrows path. ( I only chose FUSCIA, as the typically used color code of orange does not show up contrasting enough aside the RED main B+)

If voltage is present there the next move would to be testing and confirming that plate and screen voltages on the rest of the tubes are present.

That's about it for now. . . .standing by

de Edd
:
:EMUD Senior 60 mark-up Schematic. . . . . . . src=http://img21.imageshack.us/img21/1710/emudsenior60finalmarkup.png>

Hi Edd,

I thank you for your help. Your detailed reply with marked-up schematatic is beyond my expectation. Your instructions are easy to fllow and very logical. While reseaching the web after I sent the post to you I ran into another thread with similar question from another gentleman and he was also advised to replace 1k resistor (R39). So your assessment is correct that R39 is the culprit. I wish you were close by ( I live and work near Los Angeles, so I can signup and be your student to learn the tube radio...Back to radio, locating the EL84 since location is identified on the back cover. As I am just getting into this hobby I have not acquired all the necessary basic tools (I have the list) so obviouly no workbench. A freind of mine who is quite savvy with this kind work will help me so please give me few days and I will report the results. One question, should I go ahead and replace the R39 as first step and see what happens. Also would be kind enough to recommend basic tools I need to acquire. I also plan to to recap the radio in near future. I have read many articles on the web and they are quite informative and I continue to educate myself. Last weekend after I got radio I removed the bottom cover, dust it off and study the component under the chasis. The spring off the AM push button was unhooked so fixed that. Cleaned the dial bulbs and cleaned up area I can reach without any disassembly. The cabinet is in execellent condition and requires no additional work other than little polish and buff-up. My plan is to get this radio all fixed up and present it to my freind who really appreciates tube radio.

Please do not hesitate to send any recomendation, advise, information so I can start this hobby the correct way and enjoyment of life time. I am writing this from work so whe I get home I will study radio with schematic in hand so I get to the radio better.

Thanks again, Vinod

UPDATE: Studied the components using schematic, quite a education! I tried to locate R39 but was not successful, may be it is under the chasis. Will open up bottom cover today and see if I can locate R39. Another challange is how to power up radio after I remove the back cover since input plug is attached to cover and when I remove the cover no power (good safety feature though). I will figure out safe way to power the radio with back removed. Any recommendation will be appreciated. I can not thank you enough!

Regards, Vinod

If you have Voltage on pin 7 of the EL 84 but none on pin 9, R39 is open. Or, with power off, if you can measure ikOhm between pins 7 and 9, the resistor is good.
Lewis

Lewis again:
There is a slight possibility that the output transformer primary has an open winding. Let's not think about that right, as R39 would blow before the transformer, but there is always that stinking possibisity.
Lewis

Thanks Lewis, I am little confused when I opened the bottom cover to see pins on EL84, could not identify pin 9 or pin 7. Also could not locate R39 either. As I am quite to new to tube radio I am hesitant. EM84 is close output xformer and behind EM80, righ?t?
Will continue study schematic and physical layout on chasis.

regards, Vinod

Wires from the output tube, EL 84, will connect to the output transformer. The two wires going from the transformer to the tube should have 1000 Ohms between them. There you have a quick check of the 1K resistor. Also, the two wires should connect to the tube with one pin between them. That is pin 8. Pin nine should be next to a space in the socket connectors. Jump across that space, and you are at pin one. This can get confusing as, when you are counting pins things change from clockwise to counterclockwise as you go from the top of the chassis to the bottom. Remember, from the output transformer to pins seven and nine. Pin nine is the one next to the space.
Lewis

I do not have much time this weekend but was able go over your last post, study schematic and open up bottom cover. Looking at the bottom (radio upside down) I was able to locate Pin 9 and 7. I was able to locate R39 with color coding help from you. To confirm compared color with R38(1K connected to pin 2. It seems that removal/replacment will have to be done from bottom since it is under output xformer and close to Front/Right corner, visble from back but not good access to do the replacement. Radio upside down bottom cover removed and back cover in place will provide power for B+ check on 7 and 9, any problem to power up radio upside down? Another observation, removed the EL 84 to look at the pins, to my surprise it is EL 84/6B05 RCA USA, I was hoping to see German brand. May be replaced in the past? I do not want to make this repair harder as you advised, and don't want to remove chasis if possible. I know I am going slow and asking lot of questions but I want to understand each step before taking action. By the way I saw comments from others and how your contribution/help is appreciated, especially newcomers like me.

Thanks, Vinod

With the help of the freind put the radio on the bench. EL84 Pin 7 measures 381VDC. No/negigible Voltage on the pin 9. I noticed another power resistor next to R39 (?), it is not like color banded but pretty shaggy/burned out looking brown and very closed to chasis, measured zero resistance across. Cut the one lead off this brown resistor and hooked up temperory 1K resistor, and turned on radio, little static noise through the speaker and the little smoke around middle of the chasis, turned off power immediately and looked for origin of the smoke or burned component, could not find anything. Removed the temperory 1K and powered the radio. All tubes glow and screen bulbs/main fuse OK. I hope I have not inflicted any damage. I can send picture of the brown resistor location but I don't know if I can attach the photo to this post. Any advise on what to do next?

Thanks, Vinod

Thanks for post and advise, I was able to locate pin 7,8 and 9 and also R39. Let us hope R39 is the bad boy! I don't want to think about xformer either! Will take measurements in couple of days as time permits, little busy this weekend.

Thanks, Vinod

My money is on R39, but did you measure between pons 7 and 9?
Lewis

Thanks, Vinod

Sir Vinod . . . . Soooo. . . . . it looks like the END result in the problem was the final opening of that R39 resistor, but that being ONLY because there was an overloading presented to it by circuitry on down the supply line being fed from it. I have now ”mortified” the initial working schema, in the extending of the Sub B+ path on past its having initially stopped at the Fuscia arrow’s end. . . . .its extension line is now black bordered. The very first consideration would be the second section of the C70 electrolytic, but its best to set that aside since you have detected a clue ELSEWHERE on the chassis, apart from that caps area. Following down the line we first see the route up to the R31 resistor, which can not be the problem at that high of a resistive value. . .other dead ends will be marked off in that same manner. Moving to the left, we see an initial possibility in R18 if the C46 on its other side is shorted, or is there is some other “short” on past that resistor. The next path to R17 is a dead end, then you have the same consideration with R13 if it is having a shorted C36 on past it or the same situation as the prior R18. Then there are 2 more dead ends off to the left corner and then you drop straight down to find feed thru capacitor C12, now in my mind, it is the most likely so far in its actually shorting thru and arcing to ground, I have seen them arcing and leaving black carbonization around them. Then of course there is R5. . .2K on past it. . .that it feeds, but I really don’t suspect R5. A possible quick test for that area would be to band switch the unit OUT OF FM mode, to see if the fallacy still exists with the R39 overheating, if no problem then, continue the search in the FM tuner at the bottom left corner , with that feed thru cap and the 2K resistor and circuitry on past them. I would think that you would now be able to zero in on the culprit, by virtue of it being discolored, or burnt,if being a resistor. Or additionally, you could use metering , placed in its ohmmeter function in measuring from that buss to ground then shed off connections one at a time, until the overloading component is pinpointed . Suspect components have been boxed and highlighted. . . . .Standing by. . . . . 73's de Edd

Thumbnail Schematic of the Sub B+ Circuitry of the Emud 60. . . .

Quite a bit of information and I am trying to understand/digest it. Though your last instruction as test one section at a time to isolate culprit, though it is slow process but certainly teaches a lot.
I may find dicolored or burnt item. My freind is not coming close to this baby, he had never seen tube radio and little jolt he got from residue +voltage made him wonder about tube radio. I have located a gentleman who likes to tinker with tube radio and I may ask for his help. This is the first time I am looking at schematic after 30+ years and I am quite rusty. I do appreciate you taking time to study the problem, marking up schematic and providing suggestions. I am gonna slow from now on and see what I find. Though 300plus +V on pin 7 bothers me, and that unkown brown power resistor next to R39.

Thanks, Vinod

-----------------------------------------------
:Sir Vinod . . . .
:
:Soooo. . . . . it looks like the END result in the problem was the final opening of that R39 resistor, but that being ONLY because there was an overloading presented to it by circuitry on down the supply line being fed from it.

:I have now ”mortified” the initial working schema, in the extending of the Sub B+ path on past its having initially stopped at the Fuscia arrow’s end. . . . .its extension line is now black bordered.

:The very first consideration would be the second section of the C70 electrolytic, but its best to set that aside since you have detected a clue ELSEWHERE on the chassis, apart from that caps area.
:
:Following down the line we first see the route up to the R31 resistor, which can not be the problem at that high of a resistive value. . .other dead ends will be marked off in that same manner.
:
:Moving to the left, we see an initial possibility in R18 if the C46 on its other side is shorted, or is there is some other “short” on past that resistor.
:
:The next path to R17 is a dead end, then you have the same consideration with R13 if it is having a shorted C36 on past it or the same situation as the prior R18.
:
:Then there are 2 more dead ends off to the left corner and then you drop straight down to find feed thru capacitor C12, now in my mind, it is the most likely so far in its actually shorting thru and arcing to ground, I have seen them arcing and leaving black carbonization around them.
:
:Then of course there is R5. . .2K on past it. . .that it feeds, but I really don’t suspect R5.
:
:A possible quick test for that area would be to band switch the unit OUT OF FM mode, to see if the fallacy still exists with the R39 overheating, if no problem then, continue the search in the FM tuner at the bottom left corner , with that feed thru cap and the 2K resistor and circuitry on past them.
:
:I would think that you would now be able to zero in on the culprit, by virtue of it being discolored, or burnt,if being a resistor.
:
:Or additionally, you could use metering , placed in its ohmmeter function in measuring from that buss to ground then shed off connections one at a time, until the overloading component is pinpointed .
:Suspect components have been boxed and highlighted. . . . .Standing by. . . . .

73's de Edd

I am working on the same radio and I have the following symptoms: (info in this thread has been very helpful, thanks)

1. I get FM but the low end is all cracked up , all bass sounds terrible. that's best I can describe it.

I measured the point between R39(1K) & the 50Uf cap( pin 9 of EL84) , I got ~180V with EL84 in the socket. I got ~280V with the EL84 out of the socket. Voltage is about the same on pin 7 of the EL84

Voltage on C70 is ~220v & >300V with EL84 in & out respectively

I measured all the passive components in the area adn didn't find anything out of ordinary.

With EL84 out, I measure R39 to be 1K

Any suggestion ?

Ron
:Sir,
:
:Quite a bit of information and I am trying to understand/digest it. Though your last instruction as test one section at a time to isolate culprit, though it is slow process but certainly teaches a lot.
:I may find dicolored or burnt item. My freind is not coming close to this baby, he had never seen tube radio and little jolt he got from residue +voltage made him wonder about tube radio. I have located a gentleman who likes to tinker with tube radio and I may ask for his help. This is the first time I am looking at schematic after 30+ years and I am quite rusty. I do appreciate you taking time to study the problem, marking up schematic and providing suggestions. I am gonna slow from now on and see what I find. Though 300plus +V on pin 7 bothers me, and that unkown brown power resistor next to R39.
:
:Thanks, Vinod
:
:-----------------------------------------------
::Sir Vinod . . . .
::
::Soooo. . . . . it looks like the END result in the problem was the final opening of that R39 resistor, but that being ONLY because there was an overloading presented to it by circuitry on down the supply line being fed from it.
:
::I have now ”mortified” the initial working schema, in the extending of the Sub B+ path on past its having initially stopped at the Fuscia arrow’s end. . . . .its extension line is now black bordered.
:
::The very first consideration would be the second section of the C70 electrolytic, but its best to set that aside since you have detected a clue ELSEWHERE on the chassis, apart from that caps area.
::
::Following down the line we first see the route up to the R31 resistor, which can not be the problem at that high of a resistive value. . .other dead ends will be marked off in that same manner.
::
::Moving to the left, we see an initial possibility in R18 if the C46 on its other side is shorted, or is there is some other “short” on past that resistor.
::
::The next path to R17 is a dead end, then you have the same consideration with R13 if it is having a shorted C36 on past it or the same situation as the prior R18.
::
::Then there are 2 more dead ends off to the left corner and then you drop straight down to find feed thru capacitor C12, now in my mind, it is the most likely so far in its actually shorting thru and arcing to ground, I have seen them arcing and leaving black carbonization around them.
::
::Then of course there is R5. . .2K on past it. . .that it feeds, but I really don’t suspect R5.
::
::A possible quick test for that area would be to band switch the unit OUT OF FM mode, to see if the fallacy still exists with the R39 overheating, if no problem then, continue the search in the FM tuner at the bottom left corner , with that feed thru cap and the 2K resistor and circuitry on past them.
::
::I would think that you would now be able to zero in on the culprit, by virtue of it being discolored, or burnt,if being a resistor.
::
::Or additionally, you could use metering , placed in its ohmmeter function in measuring from that buss to ground then shed off connections one at a time, until the overloading component is pinpointed .
::Suspect components have been boxed and highlighted. . . . .Standing by. . . . .
:
:73's de Edd

What else control sound quality ? the 2 tone controls ? Volume control ? how about a bad EABC80 or any of the radio tuning tubes. . I might try swapping tubes with other radio to rule out bad tubes


Ron

:
:

: : : : : : :Sir Ron . . . . . : : : : : :Any suggestion ? . . . . . . :Vell, I am tellink you vot . . dat is soundink un kaboodles like: : : :The differentiation between the handling of the de-emphasis in the post FM detector circuitry that is used in der Cherman (Euro) versus der Amerikanski standards. : : :The first leading question would be if the unit seems to perform admirably well, when being in its AM mode OR with the inputting of audio from a phono, tape or CD/DVD source ? : : :Go back to AM and pick your best performing station and then set, optimize, and leave the bass and treble settings in their most aurally pleasing positions. :Then switch over to FM and see if the performance is overly high in BASS response now, if not,in days past, you must have been compensating for the extreme treble presence by tone control counter- compensation.. : : :If so, that suggests a corrective change needs to be made to the FM detector circuitry's output feed into the AF amplifier stream. :Ve are needink to shift the RC time constants from 50us delay of der (Euro) to 75us delay of der (USA). : : :With that sets designed 50 us demphasis is meaning that the set, when performing in the US on one of our 75 us delay standards, will be having the sets hi frequency performance being OVER ABUNDANT with the higher frequency treble response and a bit brassy in its sound, to compensate for that higher frequencies acoustical abberation, you are naturally wanting to either decrease the treble response via that contol or increase the bass response by use of that control . If so, with the latter being set to high, will tend to have a bass breakup or thumpiness at lower frequencies. Somewhat akin to confronting a speakers bass resonance point breakup. : : :If this seems to fit your situation, and since I am totally blind, go to YOUR unit, talk to it, and seek out the mechanical situation :relevant to the physical positioning of R/C components of C52-R26-C53 and C54, as well as if their values are in congruence with this schematics given values, a producton change might have occurred. : : :Also, if they are placed readily mechanically accessible, for the making of a very slight change to a series of them. : : :On the schematic, those components are located ~ 3 in to the left of the AF output tube, or just above the round test socket which I have marked up in [YELLOW]. : : :Separate access to Ye Olde Working Schematic can be called up direct : : : : : [ click on me . .me . MEE . . ..CLICK ..ON .. MEEEEE . . . I dare you]. : : : : :Standing by . . .Awaiting your full evaluation : : : : : : : : : :73's de Edd : : : :

:
:
:
:
:
:
:
:
:
::Hello,
::
::
::I am working on the same radio and I have the following symptoms: (info in this thread has been very helpful, thanks)
::
::1. I get FM but the low end is all cracked up , all bass sounds terrible. that's best I can describe it.
::
::I measured the point between R39(1K) & the 50Uf cap( pin 9 of EL84) , I got ~180V with EL84 in the socket. I got ~280V with the EL84 out of the socket. Voltage is about the same on pin 7 of the EL84
::
::Voltage on C70 is ~220v & >300V with EL84 in & out respectively
::
::I measured all the passive components in the area adn didn't find anything out of ordinary.
::
::With EL84 out, I measure R39 to be 1K
::
::Any suggestion ?
::
::Ron
:::Sir,
:::
:::Quite a bit of information and I am trying to understand/digest it. Though your last instruction as test one section at a time to isolate culprit, though it is slow process but certainly teaches a lot.
:::I may find dicolored or burnt item. My freind is not coming close to this baby, he had never seen tube radio and little jolt he got from residue +voltage made him wonder about tube radio. I have located a gentleman who likes to tinker with tube radio and I may ask for his help. This is the first time I am looking at schematic after 30+ years and I am quite rusty. I do appreciate you taking time to study the problem, marking up schematic and providing suggestions. I am gonna slow from now on and see what I find. Though 300plus +V on pin 7 bothers me, and that unkown brown power resistor next to R39.
:::
:::Thanks, Vinod
:::
:::-----------------------------------------------
::::Sir Vinod . . . .
::::
::::Soooo. . . . . it looks like the END result in the problem was the final opening of that R39 resistor, but that being ONLY because there was an overloading presented to it by circuitry on down the supply line being fed from it.
:::
::::I have now ”mortified” the initial working schema, in the extending of the Sub B+ path on past its having initially stopped at the Fuscia arrow’s end. . . . .its extension line is now black bordered.
:::
::::The very first consideration would be the second section of the C70 electrolytic, but its best to set that aside since you have detected a clue ELSEWHERE on the chassis, apart from that caps area.
::::
::::Following down the line we first see the route up to the R31 resistor, which can not be the problem at that high of a resistive value. . .other dead ends will be marked off in that same manner.
::::
::::Moving to the left, we see an initial possibility in R18 if the C46 on its other side is shorted, or is there is some other “short” on past that resistor.
::::
::::The next path to R17 is a dead end, then you have the same consideration with R13 if it is having a shorted C36 on past it or the same situation as the prior R18.
::::
::::Then there are 2 more dead ends off to the left corner and then you drop straight down to find feed thru capacitor C12, now in my mind, it is the most likely so far in its actually shorting thru and arcing to ground, I have seen them arcing and leaving black carbonization around them.
::::
::::Then of course there is R5. . .2K on past it. . .that it feeds, but I really don’t suspect R5.
::::
::::A possible quick test for that area would be to band switch the unit OUT OF FM mode, to see if the fallacy still exists with the R39 overheating, if no problem then, continue the search in the FM tuner at the bottom left corner , with that feed thru cap and the 2K resistor and circuitry on past them.
::::
::::I would think that you would now be able to zero in on the culprit, by virtue of it being discolored, or burnt,if being a resistor.
::::
::::Or additionally, you could use metering , placed in its ohmmeter function in measuring from that buss to ground then shed off connections one at a time, until the overloading component is pinpointed .
::::Suspect components have been boxed and highlighted. . . . .Standing by. . . . .
:::
:::73's de Edd
::
:

1. I basically have to turn bass completely off thru tone control knob in order to avoid thumpiness & cracked sound in bass. Also can't listen to it too loud

*** music sounds really bad without bass :-(

2. I tried swapping EL84 & EABC80 from a good radio, no difference.

I usupect my problem is more than FM de-emphasis.

You mentioned : R/C components of C52-R26-C53 and C54

Question : you think I should verify schematic value ? you think it can be a source for bad bass ? How about a bad speaker ?

Thanks again.

:I really appreciate your detail answer.
:
:Before I proceed , I like to once again confirm is that normal to see 180V on pin 9 of the EL84 , since the schematic indicates 250V and is going to most of the tubes. Would that put a limitation on the tube performance ? Would that result in poor sound quality ?
:
:Yes I can tune in both AM & FM stations, loud & but not clear, if I reduce volume , it help little bit. I am beginning to feel poor sound quality not only for low frequency, but mids too. I am comparing it to my Grundig 2440& 2065, they both sound beautiful. Even my Zenith G730 is a lot better.
:
:The tone control helps a little too. I get flustrated by trying different setting without much progress. By the way , I have replaced C70 & some of the ones for the rectifier & around EL84. Of couse no improvement. I did not touch any of the other caps as I know I am not supposed to.
:
:What else control sound quality ? the 2 tone controls ? Volume control ? how about a bad EABC80 or any of the radio tuning tubes. . I might try swapping tubes with other radio to rule out bad tubes
:
:
:Ron
:
::
::

:: :: :: :: :: :: ::Sir Ron . . . . . :: :: :: :: :: ::Any suggestion ? . . . . . . ::Vell, I am tellink you vot . . dat is soundink un kaboodles like: :: :: ::The differentiation between the handling of the de-emphasis in the post FM detector circuitry that is used in der Cherman (Euro) versus der Amerikanski standards. :: :: ::The first leading question would be if the unit seems to perform admirably well, when being in its AM mode OR with the inputting of audio from a phono, tape or CD/DVD source ? :: :: ::Go back to AM and pick your best performing station and then set, optimize, and leave the bass and treble settings in their most aurally pleasing positions. ::Then switch over to FM and see if the performance is overly high in BASS response now, if not,in days past, you must have been compensating for the extreme treble presence by tone control counter- compensation.. :: :: ::If so, that suggests a corrective change needs to be made to the FM detector circuitry's output feed into the AF amplifier stream. ::Ve are needink to shift the RC time constants from 50us delay of der (Euro) to 75us delay of der (USA). :: :: ::With that sets designed 50 us demphasis is meaning that the set, when performing in the US on one of our 75 us delay standards, will be having the sets hi frequency performance being OVER ABUNDANT with the higher frequency treble response and a bit brassy in its sound, to compensate for that higher frequencies acoustical abberation, you are naturally wanting to either decrease the treble response via that contol or increase the bass response by use of that control . If so, with the latter being set to high, will tend to have a bass breakup or thumpiness at lower frequencies. Somewhat akin to confronting a speakers bass resonance point breakup. :: :: ::If this seems to fit your situation, and since I am totally blind, go to YOUR unit, talk to it, and seek out the mechanical situation ::relevant to the physical positioning of R/C components of C52-R26-C53 and C54, as well as if their values are in congruence with this schematics given values, a producton change might have occurred. :: :: ::Also, if they are placed readily mechanically accessible, for the making of a very slight change to a series of them. :: :: ::On the schematic, those components are located ~ 3 in to the left of the AF output tube, or just above the round test socket which I have marked up in [YELLOW]. :: :: ::Separate access to Ye Olde Working Schematic can be called up direct : :: :: :: :: [ click on me . .me . MEE . . ..CLICK ..ON .. MEEEEE . . . I dare you]. :: :: :: :: ::Standing by . . .Awaiting your full evaluation :: :: :: :: :: :: :: :: :: ::73's de Edd :: :: :: ::

::
::
::
::
::
::
::
::
::
:::Hello,
:::
:::
:::I am working on the same radio and I have the following symptoms: (info in this thread has been very helpful, thanks)
:::
:::1. I get FM but the low end is all cracked up , all bass sounds terrible. that's best I can describe it.
:::
:::I measured the point between R39(1K) & the 50Uf cap( pin 9 of EL84) , I got ~180V with EL84 in the socket. I got ~280V with the EL84 out of the socket. Voltage is about the same on pin 7 of the EL84
:::
:::Voltage on C70 is ~220v & >300V with EL84 in & out respectively
:::
:::I measured all the passive components in the area adn didn't find anything out of ordinary.
:::
:::With EL84 out, I measure R39 to be 1K
:::
:::Any suggestion ?
:::
:::Ron
::::Sir,
::::
::::Quite a bit of information and I am trying to understand/digest it. Though your last instruction as test one section at a time to isolate culprit, though it is slow process but certainly teaches a lot.
::::I may find dicolored or burnt item. My freind is not coming close to this baby, he had never seen tube radio and little jolt he got from residue +voltage made him wonder about tube radio. I have located a gentleman who likes to tinker with tube radio and I may ask for his help. This is the first time I am looking at schematic after 30+ years and I am quite rusty. I do appreciate you taking time to study the problem, marking up schematic and providing suggestions. I am gonna slow from now on and see what I find. Though 300plus +V on pin 7 bothers me, and that unkown brown power resistor next to R39.
::::
::::Thanks, Vinod
::::
::::-----------------------------------------------
:::::Sir Vinod . . . .
:::::
:::::Soooo. . . . . it looks like the END result in the problem was the final opening of that R39 resistor, but that being ONLY because there was an overloading presented to it by circuitry on down the supply line being fed from it.
::::
:::::I have now ”mortified” the initial working schema, in the extending of the Sub B+ path on past its having initially stopped at the Fuscia arrow’s end. . . . .its extension line is now black bordered.
::::
:::::The very first consideration would be the second section of the C70 electrolytic, but its best to set that aside since you have detected a clue ELSEWHERE on the chassis, apart from that caps area.
:::::
:::::Following down the line we first see the route up to the R31 resistor, which can not be the problem at that high of a resistive value. . .other dead ends will be marked off in that same manner.
:::::
:::::Moving to the left, we see an initial possibility in R18 if the C46 on its other side is shorted, or is there is some other “short” on past that resistor.
:::::
:::::The next path to R17 is a dead end, then you have the same consideration with R13 if it is having a shorted C36 on past it or the same situation as the prior R18.
:::::
:::::Then there are 2 more dead ends off to the left corner and then you drop straight down to find feed thru capacitor C12, now in my mind, it is the most likely so far in its actually shorting thru and arcing to ground, I have seen them arcing and leaving black carbonization around them.
:::::
:::::Then of course there is R5. . .2K on past it. . .that it feeds, but I really don’t suspect R5.
:::::
:::::A possible quick test for that area would be to band switch the unit OUT OF FM mode, to see if the fallacy still exists with the R39 overheating, if no problem then, continue the search in the FM tuner at the bottom left corner , with that feed thru cap and the 2K resistor and circuitry on past them.
:::::
:::::I would think that you would now be able to zero in on the culprit, by virtue of it being discolored, or burnt,if being a resistor.
:::::
:::::Or additionally, you could use metering , placed in its ohmmeter function in measuring from that buss to ground then shed off connections one at a time, until the overloading component is pinpointed .
:::::Suspect components have been boxed and highlighted. . . . .Standing by. . . . .
::::
::::73's de Edd
:::
::
:

Pin 9 181V
Pin 7 188.3V
Pin 3 14.55V
Pin1 14.41
B+ 221V

Thanks.

:
:

: : : : : : :Sir Ron . . . . . : : : : :OK then, in moving over to evaluating the output stage, what is the voltage level om the plate of the AF output tube and also at the B+ input to the output transformer, considering that the screen is being way down at the 175 ? V level. : : : : : : : :73's de Edd : : : :

:
:
:
:
:
:
:
:: Couldn't wait to give more update:
::
::1. I basically have to turn bass completely off thru tone control knob in order to avoid thumpiness & cracked sound in bass. Also can't listen to it too loud
::
::*** music sounds really bad without bass :-(
::
::
::2. I tried swapping EL84 & EABC80 from a good radio, no difference.
::
::I usupect my problem is more than FM de-emphasis.
::
::You mentioned : R/C components of C52-R26-C53 and C54
::
::Question : you think I should verify schematic value ? you think it can be a source for bad bass ? How about a bad speaker ?
::
::
::Thanks again.
::
:::I really appreciate your detail answer.
:::
:::Before I proceed , I like to once again confirm is that normal to see 180V on pin 9 of the EL84 , since the schematic indicates 250V and is going to most of the tubes. Would that put a limitation on the tube performance ? Would that result in poor sound quality ?
:::
:::Yes I can tune in both AM & FM stations, loud & but not clear, if I reduce volume , it help little bit. I am beginning to feel poor sound quality not only for low frequency, but mids too. I am comparing it to my Grundig 2440& 2065, they both sound beautiful. Even my Zenith G730 is a lot better.
:::
:::The tone control helps a little too. I get flustrated by trying different setting without much progress. By the way , I have replaced C70 & some of the ones for the rectifier & around EL84. Of couse no improvement. I did not touch any of the other caps as I know I am not supposed to.
:::
:::What else control sound quality ? the 2 tone controls ? Volume control ? how about a bad EABC80 or any of the radio tuning tubes. . I might try swapping tubes with other radio to rule out bad tubes
:::
:::
:::Ron
:::
::::
::::

:::: :::: :::: :::: :::: :::: ::::Sir Ron . . . . . :::: :::: :::: :::: :::: ::::Any suggestion ? . . . . . . ::::Vell, I am tellink you vot . . dat is soundink un kaboodles like: :::: :::: ::::The differentiation between the handling of the de-emphasis in the post FM detector circuitry that is used in der Cherman (Euro) versus der Amerikanski standards. :::: :::: ::::The first leading question would be if the unit seems to perform admirably well, when being in its AM mode OR with the inputting of audio from a phono, tape or CD/DVD source ? :::: :::: ::::Go back to AM and pick your best performing station and then set, optimize, and leave the bass and treble settings in their most aurally pleasing positions. ::::Then switch over to FM and see if the performance is overly high in BASS response now, if not,in days past, you must have been compensating for the extreme treble presence by tone control counter- compensation.. :::: :::: ::::If so, that suggests a corrective change needs to be made to the FM detector circuitry's output feed into the AF amplifier stream. ::::Ve are needink to shift the RC time constants from 50us delay of der (Euro) to 75us delay of der (USA). :::: :::: ::::With that sets designed 50 us demphasis is meaning that the set, when performing in the US on one of our 75 us delay standards, will be having the sets hi frequency performance being OVER ABUNDANT with the higher frequency treble response and a bit brassy in its sound, to compensate for that higher frequencies acoustical abberation, you are naturally wanting to either decrease the treble response via that contol or increase the bass response by use of that control . If so, with the latter being set to high, will tend to have a bass breakup or thumpiness at lower frequencies. Somewhat akin to confronting a speakers bass resonance point breakup. :::: :::: ::::If this seems to fit your situation, and since I am totally blind, go to YOUR unit, talk to it, and seek out the mechanical situation ::::relevant to the physical positioning of R/C components of C52-R26-C53 and C54, as well as if their values are in congruence with this schematics given values, a producton change might have occurred. :::: :::: ::::Also, if they are placed readily mechanically accessible, for the making of a very slight change to a series of them. :::: :::: ::::On the schematic, those components are located ~ 3 in to the left of the AF output tube, or just above the round test socket which I have marked up in [YELLOW]. :::: :::: ::::Separate access to Ye Olde Working Schematic can be called up direct : :::: :::: :::: :::: [ click on me . .me . MEE . . ..CLICK ..ON .. MEEEEE . . . I dare you]. :::: :::: :::: :::: ::::Standing by . . .Awaiting your full evaluation :::: :::: :::: :::: :::: :::: :::: :::: :::: ::::73's de Edd :::: :::: :::: ::::

::::
::::
::::
::::
::::
::::
::::
::::
::::
:::::Hello,
:::::
:::::
:::::I am working on the same radio and I have the following symptoms: (info in this thread has been very helpful, thanks)
:::::
:::::1. I get FM but the low end is all cracked up , all bass sounds terrible. that's best I can describe it.
:::::
:::::I measured the point between R39(1K) & the 50Uf cap( pin 9 of EL84) , I got ~180V with EL84 in the socket. I got ~280V with the EL84 out of the socket. Voltage is about the same on pin 7 of the EL84
:::::
:::::Voltage on C70 is ~220v & >300V with EL84 in & out respectively
:::::
:::::I measured all the passive components in the area adn didn't find anything out of ordinary.
:::::
:::::With EL84 out, I measure R39 to be 1K
:::::
:::::Any suggestion ?
:::::
:::::Ron
::::::Sir,
::::::
::::::Quite a bit of information and I am trying to understand/digest it. Though your last instruction as test one section at a time to isolate culprit, though it is slow process but certainly teaches a lot.
::::::I may find dicolored or burnt item. My freind is not coming close to this baby, he had never seen tube radio and little jolt he got from residue +voltage made him wonder about tube radio. I have located a gentleman who likes to tinker with tube radio and I may ask for his help. This is the first time I am looking at schematic after 30+ years and I am quite rusty. I do appreciate you taking time to study the problem, marking up schematic and providing suggestions. I am gonna slow from now on and see what I find. Though 300plus +V on pin 7 bothers me, and that unkown brown power resistor next to R39.
::::::
::::::Thanks, Vinod
::::::
::::::-----------------------------------------------
:::::::Sir Vinod . . . .
:::::::
:::::::Soooo. . . . . it looks like the END result in the problem was the final opening of that R39 resistor, but that being ONLY because there was an overloading presented to it by circuitry on down the supply line being fed from it.
::::::
:::::::I have now ”mortified” the initial working schema, in the extending of the Sub B+ path on past its having initially stopped at the Fuscia arrow’s end. . . . .its extension line is now black bordered.
::::::
:::::::The very first consideration would be the second section of the C70 electrolytic, but its best to set that aside since you have detected a clue ELSEWHERE on the chassis, apart from that caps area.
:::::::
:::::::Following down the line we first see the route up to the R31 resistor, which can not be the problem at that high of a resistive value. . .other dead ends will be marked off in that same manner.
:::::::
:::::::Moving to the left, we see an initial possibility in R18 if the C46 on its other side is shorted, or is there is some other “short” on past that resistor.
:::::::
:::::::The next path to R17 is a dead end, then you have the same consideration with R13 if it is having a shorted C36 on past it or the same situation as the prior R18.
:::::::
:::::::Then there are 2 more dead ends off to the left corner and then you drop straight down to find feed thru capacitor C12, now in my mind, it is the most likely so far in its actually shorting thru and arcing to ground, I have seen them arcing and leaving black carbonization around them.
:::::::
:::::::Then of course there is R5. . .2K on past it. . .that it feeds, but I really don’t suspect R5.
:::::::
:::::::A possible quick test for that area would be to band switch the unit OUT OF FM mode, to see if the fallacy still exists with the R39 overheating, if no problem then, continue the search in the FM tuner at the bottom left corner , with that feed thru cap and the 2K resistor and circuitry on past them.
:::::::
:::::::I would think that you would now be able to zero in on the culprit, by virtue of it being discolored, or burnt,if being a resistor.
:::::::
:::::::Or additionally, you could use metering , placed in its ohmmeter function in measuring from that buss to ground then shed off connections one at a time, until the overloading component is pinpointed .
:::::::Suspect components have been boxed and highlighted. . . . .Standing by. . . . .
::::::
::::::73's de Edd
:::::
::::
:::
::
:

Thanks again for you help.
From my previous measurements:

Pin 9 181V
Pin 7 188.3V
Pin 3 14.55V
Pin2(I called Pin1 in last message) 14.41V
B+ 221V

Also

EL84 in out

Pin 9 180V 280V
B+ 220V >300V

I am not sure which pin is AC filament on EL84, so I just measured voltage going to pilot light since they are supposed to tie together according to schematic. ( I hope I am right ), it is 6.3 VAC

R39 measured to be 1.036K ( although it looks very rusty, I might change it as soon as I can buy one, would 2W or higher be OK))

Since I have pin 2 & 3 measured reference to ground, the voltage accross them should be 14.55-14.41= 0.14V

I did not changed R37 or C64

My pin 1 voltage is actually Pin 2 , my mistake

Ron

:
:

: : : : : : :Sir Ron . . . . . : : : : : :Me thinks that we have some somewhat of a discreptancy on one voltage test point supplied, and that being the pin #1 reading , which my Ruhhh Cee Aye Toobie Manual shows as being NO connection on an EL84, but it just might have its pin one used as a convenient tie lug for other adjunct wiring. : : :The overall B+ voltage is lower that the schematic specifies, so lets work with consideration one, which would be the monitoring of the AC filament voltage across the EL84, since it IS a high current consumer, then you see what that voltage is and : if it is somewhat less that that 6.3 Vac level. : : :If so, move to the line taps switch associated with the primary of the power transformer and see if another tap will get it at the closest to 6.3 vac filament powering level. : : :If that switch was in initially set in error, that could account for the sets whole B+ level being lower than its norm , also. : : :Any chance that you have changed out the cathode electrolytic cap across the 150 ohm cathode resistor of the AF out ? : : :Also give me some resistance checks of that cathode resistor, the R39 resistor that is supplying a sub B+ level to the rest of the set. : : :Lastly . . .in referencing to the AF output tube . . . take DC metering and stab its negative test prod into pin #2, along with taking the positive lead and stabbing its prod into pin #3 . Give us that voltage reading. : : : :That's all for now . . . . : : : : : :73's de Edd : : : :

:
:
:
:
:
:
:
:
:
::here are they are:
::I measured all pins on the EL84
::
::Pin 9 181V
::Pin 7 188.3V
::Pin 3 14.55V
::Pin1 14.41
::B+ 221V
::
::Thanks.
::
::
::
:::
:::

::: ::: ::: ::: ::: ::: :::Sir Ron . . . . . ::: ::: ::: ::: :::OK then, in moving over to evaluating the output stage, what is the voltage level om the plate of the AF output tube and also at the B+ input to the output transformer, considering that the screen is being way down at the 175 ? V level. ::: ::: ::: ::: ::: ::: ::: :::73's de Edd ::: ::: ::: :::

:::
:::
:::
:::
:::
:::
:::
:::: Couldn't wait to give more update:
::::
::::1. I basically have to turn bass completely off thru tone control knob in order to avoid thumpiness & cracked sound in bass. Also can't listen to it too loud
::::
::::*** music sounds really bad without bass :-(
::::
::::
::::2. I tried swapping EL84 & EABC80 from a good radio, no difference.
::::
::::I usupect my problem is more than FM de-emphasis.
::::
::::You mentioned : R/C components of C52-R26-C53 and C54
::::
::::Question : you think I should verify schematic value ? you think it can be a source for bad bass ? How about a bad speaker ?
::::
::::
::::Thanks again.
::::
:::::I really appreciate your detail answer.
:::::
:::::Before I proceed , I like to once again confirm is that normal to see 180V on pin 9 of the EL84 , since the schematic indicates 250V and is going to most of the tubes. Would that put a limitation on the tube performance ? Would that result in poor sound quality ?
:::::
:::::Yes I can tune in both AM & FM stations, loud & but not clear, if I reduce volume , it help little bit. I am beginning to feel poor sound quality not only for low frequency, but mids too. I am comparing it to my Grundig 2440& 2065, they both sound beautiful. Even my Zenith G730 is a lot better.
:::::
:::::The tone control helps a little too. I get flustrated by trying different setting without much progress. By the way , I have replaced C70 & some of the ones for the rectifier & around EL84. Of couse no improvement. I did not touch any of the other caps as I know I am not supposed to.
:::::
:::::What else control sound quality ? the 2 tone controls ? Volume control ? how about a bad EABC80 or any of the radio tuning tubes. . I might try swapping tubes with other radio to rule out bad tubes
:::::
:::::
:::::Ron
:::::
::::::
::::::

:::::: :::::: :::::: :::::: :::::: :::::: ::::::Sir Ron . . . . . :::::: :::::: :::::: :::::: :::::: ::::::Any suggestion ? . . . . . . ::::::Vell, I am tellink you vot . . dat is soundink un kaboodles like: :::::: :::::: ::::::The differentiation between the handling of the de-emphasis in the post FM detector circuitry that is used in der Cherman (Euro) versus der Amerikanski standards. :::::: :::::: ::::::The first leading question would be if the unit seems to perform admirably well, when being in its AM mode OR with the inputting of audio from a phono, tape or CD/DVD source ? :::::: :::::: ::::::Go back to AM and pick your best performing station and then set, optimize, and leave the bass and treble settings in their most aurally pleasing positions. ::::::Then switch over to FM and see if the performance is overly high in BASS response now, if not,in days past, you must have been compensating for the extreme treble presence by tone control counter- compensation.. :::::: :::::: ::::::If so, that suggests a corrective change needs to be made to the FM detector circuitry's output feed into the AF amplifier stream. ::::::Ve are needink to shift the RC time constants from 50us delay of der (Euro) to 75us delay of der (USA). :::::: :::::: ::::::With that sets designed 50 us demphasis is meaning that the set, when performing in the US on one of our 75 us delay standards, will be having the sets hi frequency performance being OVER ABUNDANT with the higher frequency treble response and a bit brassy in its sound, to compensate for that higher frequencies acoustical abberation, you are naturally wanting to either decrease the treble response via that contol or increase the bass response by use of that control . If so, with the latter being set to high, will tend to have a bass breakup or thumpiness at lower frequencies. Somewhat akin to confronting a speakers bass resonance point breakup. :::::: :::::: ::::::If this seems to fit your situation, and since I am totally blind, go to YOUR unit, talk to it, and seek out the mechanical situation ::::::relevant to the physical positioning of R/C components of C52-R26-C53 and C54, as well as if their values are in congruence with this schematics given values, a producton change might have occurred. :::::: :::::: ::::::Also, if they are placed readily mechanically accessible, for the making of a very slight change to a series of them. :::::: :::::: ::::::On the schematic, those components are located ~ 3 in to the left of the AF output tube, or just above the round test socket which I have marked up in [YELLOW]. :::::: :::::: ::::::Separate access to Ye Olde Working Schematic can be called up direct : :::::: :::::: :::::: :::::: [ click on me . .me . MEE . . ..CLICK ..ON .. MEEEEE . . . I dare you]. :::::: :::::: :::::: :::::: ::::::Standing by . . .Awaiting your full evaluation :::::: :::::: :::::: :::::: :::::: :::::: :::::: :::::: :::::: ::::::73's de Edd :::::: :::::: :::::: ::::::

::::::
::::::
::::::
::::::
::::::
::::::
::::::
::::::
::::::
:::::::Hello,
:::::::
:::::::
:::::::I am working on the same radio and I have the following symptoms: (info in this thread has been very helpful, thanks)
:::::::
:::::::1. I get FM but the low end is all cracked up , all bass sounds terrible. that's best I can describe it.
:::::::
:::::::I measured the point between R39(1K) & the 50Uf cap( pin 9 of EL84) , I got ~180V with EL84 in the socket. I got ~280V with the EL84 out of the socket. Voltage is about the same on pin 7 of the EL84
:::::::
:::::::Voltage on C70 is ~220v & >300V with EL84 in & out respectively
:::::::
:::::::I measured all the passive components in the area adn didn't find anything out of ordinary.
:::::::
:::::::With EL84 out, I measure R39 to be 1K
:::::::
:::::::Any suggestion ?
:::::::
:::::::Ron
::::::::Sir,
::::::::
::::::::Quite a bit of information and I am trying to understand/digest it. Though your last instruction as test one section at a time to isolate culprit, though it is slow process but certainly teaches a lot.
::::::::I may find dicolored or burnt item. My freind is not coming close to this baby, he had never seen tube radio and little jolt he got from residue +voltage made him wonder about tube radio. I have located a gentleman who likes to tinker with tube radio and I may ask for his help. This is the first time I am looking at schematic after 30+ years and I am quite rusty. I do appreciate you taking time to study the problem, marking up schematic and providing suggestions. I am gonna slow from now on and see what I find. Though 300plus +V on pin 7 bothers me, and that unkown brown power resistor next to R39.
::::::::
::::::::Thanks, Vinod
::::::::
::::::::-----------------------------------------------
:::::::::Sir Vinod . . . .
:::::::::
:::::::::Soooo. . . . . it looks like the END result in the problem was the final opening of that R39 resistor, but that being ONLY because there was an overloading presented to it by circuitry on down the supply line being fed from it.
::::::::
:::::::::I have now ”mortified” the initial working schema, in the extending of the Sub B+ path on past its having initially stopped at the Fuscia arrow’s end. . . . .its extension line is now black bordered.
::::::::
:::::::::The very first consideration would be the second section of the C70 electrolytic, but its best to set that aside since you have detected a clue ELSEWHERE on the chassis, apart from that caps area.
:::::::::
:::::::::Following down the line we first see the route up to the R31 resistor, which can not be the problem at that high of a resistive value. . .other dead ends will be marked off in that same manner.
:::::::::
:::::::::Moving to the left, we see an initial possibility in R18 if the C46 on its other side is shorted, or is there is some other “short” on past that resistor.
:::::::::
:::::::::The next path to R17 is a dead end, then you have the same consideration with R13 if it is having a shorted C36 on past it or the same situation as the prior R18.
:::::::::
:::::::::Then there are 2 more dead ends off to the left corner and then you drop straight down to find feed thru capacitor C12, now in my mind, it is the most likely so far in its actually shorting thru and arcing to ground, I have seen them arcing and leaving black carbonization around them.
:::::::::
:::::::::Then of course there is R5. . .2K on past it. . .that it feeds, but I really don’t suspect R5.
:::::::::
:::::::::A possible quick test for that area would be to band switch the unit OUT OF FM mode, to see if the fallacy still exists with the R39 overheating, if no problem then, continue the search in the FM tuner at the bottom left corner , with that feed thru cap and the 2K resistor and circuitry on past them.
:::::::::
:::::::::I would think that you would now be able to zero in on the culprit, by virtue of it being discolored, or burnt,if being a resistor.
:::::::::
:::::::::Or additionally, you could use metering , placed in its ohmmeter function in measuring from that buss to ground then shed off connections one at a time, until the overloading component is pinpointed .
:::::::::Suspect components have been boxed and highlighted. . . . .Standing by. . . . .
::::::::
::::::::73's de Edd
:::::::
::::::
:::::
::::
:::
::
:

It works !

I promise I will go back and do all the analysis you suggested. I changed C68, the decoupling cap from EABC80 to EL84. the problem is exactly as you suppected. I got my bass back and listening to some real music now( jazz of course).

I also changed R38 as it is in pretty bad shape.

I took picture of the bad components and emailed to you since I don't know how to attached file here.

Again, you don't know how much I appreciate you help.

Ron

:
:
:

: : : : : : : :Sir Ron. . . . . : : : : : : : : : :Since I have pin 2 & 3 measured reference to ground, the voltage accross them should be 14.55-14.41= 0.14V : : : : : : :Wel l l l . . . I really would have liked to have had the 1st grid measurements at the specified manner and points . . but with a bit of hypothesizing and fully interpolating, we can work around that. : : :It seems that you have "Troubles right here in river city" . . a la lil' Abner . . . and that "troubles" seems to be the probable fault of coupling capacitor C63 from the plate of the EABC80 to the 1st grid of the EL 84. It seems to be leaking DC voltage thru, and is upsetting the 1st grid biasing level on the AF output. Skewing so high . . .even above class A operation . . that there is a constant drain on the B+ supply and pulling it down. : : :But the most invasive conditon, is that by having such a HIGH positive bias level on that 1st grid, that there will then be the additional summing of that voltage level as it combines with a complex incoming audio AC waveform . : : :If you have the volume down low, the sound might be tolerable, but as you advance the volume, the increased peak to peak AC audio level will have its positive nodes driving the AF output at the EL84 plate into a slightly clipped condition. : : :Up the volume even a bit more and there will be a shift to starting a flattening of the top of the waveform. : : :Bring up the volume still more, and the top half of the audio waveform at the EL84 plate assuredly will have transitioned intself into a very nasty square wave and the affected audio should sound like "bleep". : : :PLUS, the overall power output capability has topped out. : : : : :Now, I am tellink you vat ve vill be doink . . .a la Katzenjammer Kids . . . is the initial tube warm of of the set, volume at minimum, , then measure the plate voltage on the EABC80 that feeds up to the EL84 . Power down the unit. : : :Take one C63 wire lead loose at the end that feeds to the EL84. : : :Prepare DC metering, negative lead going to ground, and the positive lead will be going to that floating C63 lead ( a clip lead might help in the RETENTION of that connection). : : :Power up the set, allow tube filament warm up time, short that loose cap lead to ground so that the cap will IMMEDIATELY fully charge up and thereby not require 3 mins to fully charge up, when it is charging up thru the High Z charge path, other wise afforded by a DVM solely being its closed loop resistive return element. : : :Now I am fully expecting you to see DC voltage presence on that metering of the floating lead of C63 . . .to fully confirm short to ground and see if the voltage does build right up again. ( Curious ?. .How close is it to that EABC 80 plate voltage on its other side, as it was previously measured ?) : : :If having more than 50-75 mv DC leakage, you are in the market for a brand new C63, but test the new one in the same manner after its " 1/2 " installation. : : :When you finalize installation , warm up the unit and do the INITIALLY SPECIFIED cathode to 1st grid testing of the EL84 and I am now hoping for a middle of the road biasing level, it now being at approximately minus 7.5 volts. : : :Shake down the system, and see if you now don't have much "mo better" sound from the unit ? : : : :Additionally . . you query: : : : : :R39 measured to be 1.036K ( although it looks very rusty, I might change it as soon as I can buy one, would 2W or higher be OK : : : : :A 2 watt metal film unit, used in that application, should exhibit a half life of 2 eons for you . : : : : : : :Standing by . . . .somewhere ? . . .but I know not where ! : : : : : : :73's de Edd : : : : :

:
:
:
:
:
:
:
:
:
:
::Hi Edd
::
::Thanks again for you help.
::From my previous measurements:
::
::Pin 9 181V
::Pin 7 188.3V
::Pin 3 14.55V
::Pin2(I called Pin1 in last message) 14.41V
::B+ 221V
::
::Also
::
::EL84 in out
::
::Pin 9 180V 280V
::B+ 220V >300V
::
::I am not sure which pin is AC filament on EL84, so I just measured voltage going to pilot light since they are supposed to tie together according to schematic. ( I hope I am right ), it is 6.3 VAC
::
::R39 measured to be 1.036K ( although it looks very rusty, I might change it as soon as I can buy one, would 2W or higher be OK))
::
::Since I have pin 2 & 3 measured reference to ground, the voltage accross them should be 14.55-14.41= 0.14V
::
::
::I did not changed R37 or C64
::
::
::My pin 1 voltage is actually Pin 2 , my mistake
::
::
::Ron
::
:::
:::

::: ::: ::: ::: ::: ::: :::Sir Ron . . . . . ::: ::: ::: ::: ::: :::Me thinks that we have some somewhat of a discreptancy on one voltage test point supplied, and that being the pin #1 reading , which my Ruhhh Cee Aye Toobie Manual shows as being NO connection on an EL84, but it just might have its pin one used as a convenient tie lug for other adjunct wiring. ::: ::: :::The overall B+ voltage is lower that the schematic specifies, so lets work with consideration one, which would be the monitoring of the AC filament voltage across the EL84, since it IS a high current consumer, then you see what that voltage is and ::: if it is somewhat less that that 6.3 Vac level. ::: ::: :::If so, move to the line taps switch associated with the primary of the power transformer and see if another tap will get it at the closest to 6.3 vac filament powering level. ::: ::: :::If that switch was in initially set in error, that could account for the sets whole B+ level being lower than its norm , also. ::: ::: :::Any chance that you have changed out the cathode electrolytic cap across the 150 ohm cathode resistor of the AF out ? ::: ::: :::Also give me some resistance checks of that cathode resistor, the R39 resistor that is supplying a sub B+ level to the rest of the set. ::: ::: :::Lastly . . .in referencing to the AF output tube . . . take DC metering and stab its negative test prod into pin #2, along with taking the positive lead and stabbing its prod into pin #3 . Give us that voltage reading. ::: ::: ::: :::That's all for now . . . . ::: ::: ::: ::: ::: :::73's de Edd ::: ::: ::: :::

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::::here are they are:
::::I measured all pins on the EL84
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::::Pin 9 181V
::::Pin 7 188.3V
::::Pin 3 14.55V
::::Pin1 14.41
::::B+ 221V
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::::Thanks.
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::::: ::::: ::::: ::::: ::::: ::::: :::::Sir Ron . . . . . ::::: ::::: ::::: ::::: :::::OK then, in moving over to evaluating the output stage, what is the voltage level om the plate of the AF output tube and also at the B+ input to the output transformer, considering that the screen is being way down at the 175 ? V level. ::::: ::::: ::::: ::::: ::::: ::::: ::::: :::::73's de Edd ::::: ::::: ::::: :::::

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:::::: Couldn't wait to give more update:
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::::::1. I basically have to turn bass completely off thru tone control knob in order to avoid thumpiness & cracked sound in bass. Also can't listen to it too loud
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::::::*** music sounds really bad without bass :-(
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::::::2. I tried swapping EL84 & EABC80 from a good radio, no difference.
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::::::I usupect my problem is more than FM de-emphasis.
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::::::You mentioned : R/C components of C52-R26-C53 and C54
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::::::Question : you think I should verify schematic value ? you think it can be a source for bad bass ? How about a bad speaker ?
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::::::Thanks again.
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:::::::I really appreciate your detail answer.
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:::::::Before I proceed , I like to once again confirm is that normal to see 180V on pin 9 of the EL84 , since the schematic indicates 250V and is going to most of the tubes. Would that put a limitation on the tube performance ? Would that result in poor sound quality ?
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:::::::Yes I can tune in both AM & FM stations, loud & but not clear, if I reduce volume , it help little bit. I am beginning to feel poor sound quality not only for low frequency, but mids too. I am comparing it to my Grundig 2440& 2065, they both sound beautiful. Even my Zenith G730 is a lot better.
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:::::::The tone control helps a little too. I get flustrated by trying different setting without much progress. By the way , I have replaced C70 & some of the ones for the rectifier & around EL84. Of couse no improvement. I did not touch any of the other caps as I know I am not supposed to.
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:::::::What else control sound quality ? the 2 tone controls ? Volume control ? how about a bad EABC80 or any of the radio tuning tubes. . I might try swapping tubes with other radio to rule out bad tubes
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:::::::Ron
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:::::::: :::::::: :::::::: :::::::: :::::::: :::::::: ::::::::Sir Ron . . . . . :::::::: :::::::: :::::::: :::::::: :::::::: ::::::::Any suggestion ? . . . . . . ::::::::Vell, I am tellink you vot . . dat is soundink un kaboodles like: :::::::: :::::::: ::::::::The differentiation between the handling of the de-emphasis in the post FM detector circuitry that is used in der Cherman (Euro) versus der Amerikanski standards. :::::::: :::::::: ::::::::The first leading question would be if the unit seems to perform admirably well, when being in its AM mode OR with the inputting of audio from a phono, tape or CD/DVD source ? :::::::: :::::::: ::::::::Go back to AM and pick your best performing station and then set, optimize, and leave the bass and treble settings in their most aurally pleasing positions. ::::::::Then switch over to FM and see if the performance is overly high in BASS response now, if not,in days past, you must have been compensating for the extreme treble presence by tone control counter- compensation.. :::::::: :::::::: ::::::::If so, that suggests a corrective change needs to be made to the FM detector circuitry's output feed into the AF amplifier stream. ::::::::Ve are needink to shift the RC time constants from 50us delay of der (Euro) to 75us delay of der (USA). :::::::: :::::::: ::::::::With that sets designed 50 us demphasis is meaning that the set, when performing in the US on one of our 75 us delay standards, will be having the sets hi frequency performance being OVER ABUNDANT with the higher frequency treble response and a bit brassy in its sound, to compensate for that higher frequencies acoustical abberation, you are naturally wanting to either decrease the treble response via that contol or increase the bass response by use of that control . If so, with the latter being set to high, will tend to have a bass breakup or thumpiness at lower frequencies. Somewhat akin to confronting a speakers bass resonance point breakup. :::::::: :::::::: ::::::::If this seems to fit your situation, and since I am totally blind, go to YOUR unit, talk to it, and seek out the mechanical situation ::::::::relevant to the physical positioning of R/C components of C52-R26-C53 and C54, as well as if their values are in congruence with this schematics given values, a producton change might have occurred. :::::::: :::::::: ::::::::Also, if they are placed readily mechanically accessible, for the making of a very slight change to a series of them. :::::::: :::::::: ::::::::On the schematic, those components are located ~ 3 in to the left of the AF output tube, or just above the round test socket which I have marked up in [YELLOW]. :::::::: :::::::: ::::::::Separate access to Ye Olde Working Schematic can be called up direct : :::::::: :::::::: :::::::: :::::::: [ click on me . .me . MEE . . ..CLICK ..ON .. MEEEEE . . . I dare you]. :::::::: :::::::: :::::::: :::::::: ::::::::Standing by . . .Awaiting your full evaluation :::::::: :::::::: :::::::: :::::::: :::::::: :::::::: :::::::: :::::::: :::::::: ::::::::73's de Edd :::::::: :::::::: :::::::: ::::::::

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:::::::::Hello,
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:::::::::I am working on the same radio and I have the following symptoms: (info in this thread has been very helpful, thanks)
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:::::::::1. I get FM but the low end is all cracked up , all bass sounds terrible. that's best I can describe it.
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:::::::::I measured the point between R39(1K) & the 50Uf cap( pin 9 of EL84) , I got ~180V with EL84 in the socket. I got ~280V with the EL84 out of the socket. Voltage is about the same on pin 7 of the EL84
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:::::::::Voltage on C70 is ~220v & >300V with EL84 in & out respectively
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:::::::::I measured all the passive components in the area adn didn't find anything out of ordinary.
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:::::::::With EL84 out, I measure R39 to be 1K
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:::::::::Any suggestion ?
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:::::::::Ron
::::::::::Sir,
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::::::::::Quite a bit of information and I am trying to understand/digest it. Though your last instruction as test one section at a time to isolate culprit, though it is slow process but certainly teaches a lot.
::::::::::I may find dicolored or burnt item. My freind is not coming close to this baby, he had never seen tube radio and little jolt he got from residue +voltage made him wonder about tube radio. I have located a gentleman who likes to tinker with tube radio and I may ask for his help. This is the first time I am looking at schematic after 30+ years and I am quite rusty. I do appreciate you taking time to study the problem, marking up schematic and providing suggestions. I am gonna slow from now on and see what I find. Though 300plus +V on pin 7 bothers me, and that unkown brown power resistor next to R39.
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::::::::::Thanks, Vinod
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:::::::::::Sir Vinod . . . .
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:::::::::::Soooo. . . . . it looks like the END result in the problem was the final opening of that R39 resistor, but that being ONLY because there was an overloading presented to it by circuitry on down the supply line being fed from it.
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:::::::::::I have now ”mortified” the initial working schema, in the extending of the Sub B+ path on past its having initially stopped at the Fuscia arrow’s end. . . . .its extension line is now black bordered.
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:::::::::::The very first consideration would be the second section of the C70 electrolytic, but its best to set that aside since you have detected a clue ELSEWHERE on the chassis, apart from that caps area.
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:::::::::::Following down the line we first see the route up to the R31 resistor, which can not be the problem at that high of a resistive value. . .other dead ends will be marked off in that same manner.
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:::::::::::Moving to the left, we see an initial possibility in R18 if the C46 on its other side is shorted, or is there is some other “short” on past that resistor.
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:::::::::::The next path to R17 is a dead end, then you have the same consideration with R13 if it is having a shorted C36 on past it or the same situation as the prior R18.
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:::::::::::Then there are 2 more dead ends off to the left corner and then you drop straight down to find feed thru capacitor C12, now in my mind, it is the most likely so far in its actually shorting thru and arcing to ground, I have seen them arcing and leaving black carbonization around them.
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:::::::::::Then of course there is R5. . .2K on past it. . .that it feeds, but I really don’t suspect R5.
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:::::::::::A possible quick test for that area would be to band switch the unit OUT OF FM mode, to see if the fallacy still exists with the R39 overheating, if no problem then, continue the search in the FM tuner at the bottom left corner , with that feed thru cap and the 2K resistor and circuitry on past them.
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:::::::::::I would think that you would now be able to zero in on the culprit, by virtue of it being discolored, or burnt,if being a resistor.
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:::::::::::Or additionally, you could use metering , placed in its ohmmeter function in measuring from that buss to ground then shed off connections one at a time, until the overloading component is pinpointed .
:::::::::::Suspect components have been boxed and highlighted. . . . .Standing by. . . . .
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::::::::::73's de Edd
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Sorry, that didn't work, hopefully this will- I just wanted to welcome you into the hobby of repairing old radios. I just got back into it myself and I'm having a ball. Not only that but, obviously, you've teamed up with some very knowledgable people. I bought most of my test equipt. on eBay- a LOT of Heathkit. I didn't read every post, but tool #1- get yourself a good isolation transformer. I got one on eBay for about $40. I have that inline with a variable transformer, and I hook every radio up to them. Rule #1- whenever you take a radio out of the case, put a piece of cardboard on the speaker. Trust me! Good luck and I hope we help each other out. Terry
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