The set is not oscillating. Started with the basic checks. Voltages, audio circuit checked good, put a good radio next to the Zenith and set it around 800kHz, set the zenith around 1250 and nothing. In fact nothing anywhere up and down the dial. It's just not oscillating. Checked all my wiring and pics and everything appears to be in its correct place. I've made mistakes before though. Just ask Edd who helped me with another Zenith. Same kind of problem but that set was oscillating. I had one wire in the wrong place. So I did check this one real good. It's put together the way it was when I got it but I don't know what all was done to it previously.
In the morning I'm going to try to determine which coil is which on the osc. and check them out. In the meantime if anyone has any ideas I would be glad to hear them.
Thanks,
Johnny
Johnny
:
:
I will stay tuned to your problem. I have a TO here with a similar problem. I suspect a wiring problem in mine.
I assume that the short wave works OK on your set. That is what I have here, SW is good, even great. Standard broadcast is dead.
Typically I find it is never the tube, it's the capacitor.
Best Regards,
Bill
When you get a radio that someone else has worked on and it's been what I call "Pretty Chopped Up", every wire that you have to replace don't just right it down on a note pad where it went point A to point B like I did with this one. Total complacency on my part. Maybe a little arrogance too.
Make sure that the wire you are removing coincides with the schematic location of that connection.
This set wasn't oscillating because a wire that is supposed to go from pin 4 of the 6A8 mixer to an 18K ohm resistor (R10) was actually going from pin 4 of the 7G7-1232 RF tube to the 18K resistor. I went back to my notes and my pics and it was wired wrong when I got it. I don't mind saying I've made a mistake. I've done it many times over the past 4 years of learning how to work on these sets.
Thanks for the help you gave,
Johnny
:
:::::::Hi all, Completely rebuilt this Zenith 10-S-669. New caps, resistors wiring etc. etc. Was a real mess when I got it. Don't know if it was normal to do back when but they left the old filter caps in the circuit and put new ones in parallel with the old ones. Cold solder joints. The works. Had to tear it down. Never tried attaching a URL here but the schematic is listed below.
:::::::http://www.nostalgiaair.org/PagesByModel/699/M0024699.pdf
:::::::All my voltages are good but I'm confused on the 6J5 osc. grid voltage. Schema calls out what looks like -10.5 volts but it depends on what band I'm on. BC band reads -.5 volts. All other voltages are within tolerance.
:::::::
:::::::The set is not oscillating. Started with the basic checks. Voltages, audio circuit checked good, put a good radio next to the Zenith and set it around 800kHz, set the zenith around 1250 and nothing. In fact nothing anywhere up and down the dial. It's just not oscillating. Checked all my wiring and pics and everything appears to be in its correct place. I've made mistakes before though. Just ask Edd who helped me with another Zenith. Same kind of problem but that set was oscillating. I had one wire in the wrong place. So I did check this one real good. It's put together the way it was when I got it but I don't know what all was done to it previously.
:::::::
:::::::In the morning I'm going to try to determine which coil is which on the osc. and check them out. In the meantime if anyone has any ideas I would be glad to hear them.
:::::::
:::::::Thanks,
:::::::Johnny
:::::::
::::::
::::::
::::::Put in a new 6J5.
::::::Johnnysan-
::::::
::::::Thanks for the idea but I tried two more 6J5's and it still doesn't oscillate.
:::::
:::::Johnny
::::::
::::::
:::::
::::
::::
::::Did you use new 6J5s? Check all the coils associated with the 6J5.
::::Johnnysan-
::::
::::All my cabinets are full of NOS tubes. As for checking all the coils associated with the 6J5, what coils? If you're looking at the schematic you should know that all those "coils" to the left of the 6J5 are the oscillator coil assembly. As stated earlier I'm checking the oscillator out this morning.
:::Johnny
::::
::::
:::
::
::Check the continuity of the oscillator coil and the physical lead from the plate to the next grid. Also double check the screen bypass cap. It might be connected wrong, (we all make mistakes). Also, R6 or R2 might be open. Make sure there aren't any shorts in the primary of the 1st IF.
::Terry
::
:More-
:I was on my way out the door this morning and couldn't
:finish my comment.
:I have an RCA 66X11 with the same problem, no oscillator. I've been messing with it off and on and FINALLY got around to re-capping it yesterday. I'm going back in, (forceps nurse), tonight or tomorrow. I've checked the continuity on all of the coils and the 12J7 tube checks good. Unfortunately I don't have another in stock, but it's a simple triode. Voltage checks and the signal gen next.Terry
:
|
:::::::::Hi all, Completely rebuilt this Zenith 10-S-669. New caps, resistors wiring etc. etc. Was a real mess when I got it. Don't know if it was normal to do back when but they left the old filter caps in the circuit and put new ones in parallel with the old ones. Cold solder joints. The works. Had to tear it down. Never tried attaching a URL here but the schematic is listed below. :::::::: ::::Check the continuity of the oscillator coil and the physical lead from the plate to the next grid. Also double check the screen bypass cap. It might be connected wrong, (we all make mistakes). Also, R6 or R2 might be open. Make sure there aren't any shorts in the primary of the 1st IF. :Usually it's the simple things. I tell all newbies to make drawings of what they do, and what they're going to do. If I have to replace a part that requires orientation, like an osc coil or RF can, I take photos.
:::Problem solved. Let this be a lesson to folks that might be even newer to this then I am.
::
::When you get a radio that someone else has worked on and it's been what I call "Pretty Chopped Up", every wire that you have to replace don't just right it down on a note pad where it went point A to point B like I did with this one. Total complacency on my part. Maybe a little arrogance too.
::
::Make sure that the wire you are removing coincides with the schematic location of that connection.
::
::This set wasn't oscillating because a wire that is supposed to go from pin 4 of the 6A8 mixer to an 18K ohm resistor (R10) was actually going from pin 4 of the 7G7-1232 RF tube to the 18K resistor. I went back to my notes and my pics and it was wired wrong when I got it. I don't mind saying I've made a mistake. I've done it many times over the past 4 years of learning how to work on these sets.
::
::Thanks for the help you gave,
::Johnny
:::
:::::::::http://www.nostalgiaair.org/PagesByModel/699/M0024699.pdf
:::::::::All my voltages are good but I'm confused on the 6J5 osc. grid voltage. Schema calls out what looks like -10.5 volts but it depends on what band I'm on. BC band reads -.5 volts. All other voltages are within tolerance.
:::::::::
:::::::::The set is not oscillating. Started with the basic checks. Voltages, audio circuit checked good, put a good radio next to the Zenith and set it around 800kHz, set the zenith around 1250 and nothing. In fact nothing anywhere up and down the dial. It's just not oscillating. Checked all my wiring and pics and everything appears to be in its correct place. I've made mistakes before though. Just ask Edd who helped me with another Zenith. Same kind of problem but that set was oscillating. I had one wire in the wrong place. So I did check this one real good. It's put together the way it was when I got it but I don't know what all was done to it previously.
:::::::::
:::::::::In the morning I'm going to try to determine which coil is which on the osc. and check them out. In the meantime if anyone has any ideas I would be glad to hear them.
:::::::::
:::::::::Thanks,
:::::::::Johnny
:::::::::
::::::::
::::::::Put in a new 6J5.
::::::::Johnnysan-
::::::::
::::::::Thanks for the idea but I tried two more 6J5's and it still doesn't oscillate.
:::::::
:::::::Johnny
::::::::
::::::::
:::::::
::::::
::::::
::::::Did you use new 6J5s? Check all the coils associated with the 6J5.
::::::Johnnysan-
::::::
::::::All my cabinets are full of NOS tubes. As for checking all the coils associated with the 6J5, what coils? If you're looking at the schematic you should know that all those "coils" to the left of the 6J5 are the oscillator coil assembly. As stated earlier I'm checking the oscillator out this morning.
:::::Johnny
::::::
::::::
:::::
::::
::::Terry
::::
:::More-
:::I was on my way out the door this morning and couldn't
:::finish my comment.
:::I have an RCA 66X11 with the same problem, no oscillator. I've been messing with it off and on and FINALLY got around to re-capping it yesterday. I'm going back in, (forceps nurse), tonight or tomorrow. I've checked the continuity on all of the coils and the 12J7 tube checks good. Unfortunately I don't have another in stock, but it's a simple triode. Voltage checks and the signal gen next.Terry
:::
::
:
:Congratulations. There's nothing like the feeling when you find the problem, especially a difficult one. Okay, maybe sex but I've forgotten what that's like, so I'm going with this.
:Ha ha
:Good job-
:Terry
:
Thanks Edd!
Johnny
:
:
:
:
:
:
:
:
:
:
:
:
:
:Sir Johnny . . . . .
:
:
:Would you believe . . . that just at this instant I was getting ready to pull up the old marked up schematic of
:our last concerned Z for similar referencing of its mark-ups.
:
:
:That, along with my suspects or inquiries on voltage variants.
:
:
:Now . . .not to be . . . seems it was a like miswire of a previous repair . . . a la deja vu.
:
:
:
:
:Catching miswires and parts misconnect errors:
:
:
:
:
:I can STRONGLY suggest the use a procedure that I evolved into its final refinement and has proved faultless and infallable for me.
:
:
:At NASA I wasn't involved with mere involved schematics . . . but voluminous 48" x 24" TOMES of data of the most complex electronics designs in the Universe.
:
:
:Now, be that the actual schematics, wiring / routing diagrams or even the electro-mechanics.
:
:
:I had my own personally assigned drafting team for support, and they could / were initially making my copies of any schemas to my requested sizings.
:
:
:In the earlier days, they were using what were called "blue lines", somewhat c****y, but were the state of the art in drawing enlargments at that time.
:
:
:THEN the Xerox came on line producing drawing enlargements, which was as good as one would want.
:
:
:Also, some knock off company , which I can't remember the name of, but their forte was instant enlarged copies of photographic work or microfiche dupings into giant enlargements.
:
:
:Now say I had a complex schematic, I would get it duped on up to a size where a transistor would be be ~ a 1/4 inch circle or a vacuum tube would be a 1/2--3/4 in circle, all in accordance to the whole schematics total sizing /complexity.
:
:
:That sheet then received a clear plastic covering, with the perimeter edging, being secured with draftsmans masking tape. ( That materiel won't do a number on pull off, away from the paper . . 1 day or 1 month later.)
:
:
:John Q. Public, nowadays, could use the blue painting tape.
:
:
:In my case the "clear plastic sheet" was draftmans mylar sheet, but for John Q. Public needing that LARGE of a sheet size.
:
:
:I see a clear sheeting [Clopane ?sp ] on a 4 ft wide roll , you just specify the wanteded length; to be found at Wally World with 3 options on sheet thicknesses. (I also remember seeing that product at some fabric stores and general hobby stores.)
:
:
:Lately, my drawings and schemas or PCB board layouts are usually small enough to fit on a common sheet of paper, in which case I can use a common clear plastic sheet protector sleeve, or a photograph albums sheet has a bit larger size of page with its two clear acetate flyleafs.
:
:
:Now how you use this procedure is to get your schema / drawing covered in the plastic sheet and then start on the schematic and compare to the finding on the chassis and your checking out of a components two or so connections or a wire run.
:
:
:You are checking for:
:
:
:1 . . .the proper connection of the physical part as being compared against the schematic
:
:
:2 . . .the proper part and its proper value
:
:
:If those are then in agreement I take a Blue Micro Sharpie ( Why Blue ?***) and then place cursive micro interlooped circles covering up the wire path and the component.
:
:
:Then you choose another path and complete it, until that micro portion of the schematic is left illegible.
:
:
:Then, you will have eventually COMPLETELY checked out that unit, showing up as a blue massed drawing.
:
:
:This procedure also assures you have not erred when leaving the job, be it 5 min later or a week + later.
:
:
:That which you " blued " out, had been tested / confirmed previously
:
:
:
:
:Two marking assists:
:
:
:
:If an error is made in marking , a Q-tip moistened in denatured alcohol and then blotted to a "damp" wetness will then let you roll it around to dissolve / carry away any erroneous Sharpies mismarking upon the plastic covering.
:
:
:Ever since the OSHA / Guv'mint Panic Police banned the use of xylene as the solvent in Sharpies, they haven't been worth a " bleep".
:
:
:*** Black used to be my dominant color of choice, but with their alcohol based solvent used now, the Blue dye performs the best of their 15 or so colors offered, with Red at #2 and Black( not as distinct now, more like a weaker blue/dark grey) at #3 places.
:
:
:
:
:Thassit . . . .
:
:
:
:
:
:Schematic / Drawing Copies:
:
:
:I am quite impressed with the sizing capabilities on the newer oversized printers at Copymax, centers which seem to be right beside Officemax stores, as well as the other competitions store name ?, which tend to be inside a corner of the store..
:
:
:I ws initially remembering the Zerox copiers which would take our normal page size and blow it up, and often saw contractors getting their architectural drawings produced / duped in that manner, but, with those big ones being up in the multi-bucks.($4-5.00 ? each )
:
:
:THEN I saw some go-go girl getting a digital cameras photo, being blown on up to 12x18 in in B/W . . . loooooking goooood !
:
:
:Sooooo the next time I went in, I had taken with me, a bit map of a schematic which I had prepared and stored on flash drive.
:
:
:The operator set it up and was going to make it the same size that we now are seeing the giant SAMUELS schematics, that fold out initially from 4 large pages, with data being on all sides.
:
:
:Well, he then let loose with the initial copy and it was 1/4 sized, the next copy was 1/3 sized, and by my looking over his sholder , I was seeing his error and offered procedural keyboard assistance in sizing and the neglected, required cropping, to then come out with it spitting out a perfect 1 inch bordered print.
:
:
:It was supposed to have cost ~ 80cents . . . but by him having been flustered . . . he insisted on a minimal billed item charge of 23 cents, plus a profuse flowing of thanks for the procedural tips.
:
:
:Now, who was I to refuse?
:
:
:
:73's de Edd
:
:
:
:
:
:
:
:
:
:
:
:
:
::::Problem solved. Let this be a lesson to folks that might be even newer to this then I am.
:::
:::When you get a radio that someone else has worked on and it's been what I call "Pretty Chopped Up", every wire that you have to replace don't just right it down on a note pad where it went point A to point B like I did with this one. Total complacency on my part. Maybe a little arrogance too.
:::
:::Make sure that the wire you are removing coincides with the schematic location of that connection.
:::
:::This set wasn't oscillating because a wire that is supposed to go from pin 4 of the 6A8 mixer to an 18K ohm resistor (R10) was actually going from pin 4 of the 7G7-1232 RF tube to the 18K resistor. I went back to my notes and my pics and it was wired wrong when I got it. I don't mind saying I've made a mistake. I've done it many times over the past 4 years of learning how to work on these sets.
:::
:::Thanks for the help you gave,
:::Johnny
::::
:
:
:
::::::::::Hi all, Completely rebuilt this Zenith 10-S-669. New caps, resistors wiring etc. etc. Was a real mess when I got it. Don't know if it was normal to do back when but they left the old filter caps in the circuit and put new ones in parallel with the old ones. Cold solder joints. The works. Had to tear it down. Never tried attaching a URL here but the schematic is listed below.
::::::::::http://www.nostalgiaair.org/PagesByModel/699/M0024699.pdf
::::::::::All my voltages are good but I'm confused on the 6J5 osc. grid voltage. Schema calls out what looks like -10.5 volts but it depends on what band I'm on. BC band reads -.5 volts. All other voltages are within tolerance.
::::::::::
::::::::::The set is not oscillating. Started with the basic checks. Voltages, audio circuit checked good, put a good radio next to the Zenith and set it around 800kHz, set the zenith around 1250 and nothing. In fact nothing anywhere up and down the dial. It's just not oscillating. Checked all my wiring and pics and everything appears to be in its correct place. I've made mistakes before though. Just ask Edd who helped me with another Zenith. Same kind of problem but that set was oscillating. I had one wire in the wrong place. So I did check this one real good. It's put together the way it was when I got it but I don't know what all was done to it previously.
::::::::::
::::::::::In the morning I'm going to try to determine which coil is which on the osc. and check them out. In the meantime if anyone has any ideas I would be glad to hear them.
::::::::::
::::::::::Thanks,
::::::::::Johnny
::::::::::
:::::::::
:
:
:::::::::
:::::::::Put in a new 6J5.
:::::::::Johnnysan-
:::::::::
:
:
:::::::::Thanks for the idea but I tried two more 6J5's and it still doesn't oscillate.
::::::::
::::::::Johnny
:::::::::
:::::::::
::::::::
:::::::
:
:
:::::::
:::::::Did you use new 6J5s? Check all the coils associated with the 6J5.
:::::::Johnnysan-
:::::::
:
:
:::::::All my cabinets are full of NOS tubes. As for checking all the coils associated with the 6J5, what coils? If you're looking at the schematic you should know that all those "coils" to the left of the 6J5 are the oscillator coil assembly. As stated earlier I'm checking the oscillator out this morning.
::::::Johnny
:::::::
:::::::
::::::
:::::
:
:
:
:::::Check the continuity of the oscillator coil and the physical lead from the plate to the next grid. Also double check the screen bypass cap. It might be connected wrong, (we all make mistakes). Also, R6 or R2 might be open. Make sure there aren't any shorts in the primary of the 1st IF.
:::::Terry
:
:
:::::
::::More-
::::I was on my way out the door this morning and couldn't
::::finish my comment.
::::I have an RCA 66X11 with the same problem, no oscillator. I've been messing with it off and on and FINALLY got around to re-capping it yesterday. I'm going back in, (forceps nurse), tonight or tomorrow. I've checked the continuity on all of the coils and the 12J7 tube checks good. Unfortunately I don't have another in stock, but it's a simple triode. Voltage checks and the signal gen next.Terry
::::
:::
::
:
:
:
::Usually it's the simple things. I tell all newbies to make drawings of what they do, and what they're going to do. If I have to replace a part that requires orientation, like an osc coil or RF can, I take photos.
::Congratulations. There's nothing like the feeling when you find the problem, especially a difficult one. Okay, maybe sex but I've forgotten what that's like, so I'm going with this.
::Ha ha
::Good job-
::Terry
::
:
:
: