Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
Mark
A person would need to be looking a the schematic to identify components.
Can you adjust through the horizontal frequency range and it just doesn't lock? or are out of range? If out of range it's a horizontal oscillator problem. You mentioned adjusting the frequency coil. High resistors in the circuit can increase in value or open. Caps become leaky.
If it doesn't lock look at sync separator circuit. Resistor and capacitor network along with diodes, tube or solid state.
Norm
:Hi All
: Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
:Mark
:
: A person would need to be looking a the schematic to identify components.
:
: Can you adjust through the horizontal frequency range and it just doesn't lock? or are out of range? If out of range it's a horizontal oscillator problem. You mentioned adjusting the frequency coil. High resistors in the circuit can increase in value or open. Caps become leaky.
:
: If it doesn't lock look at sync separator circuit. Resistor and capacitor network along with diodes, tube or solid state.
:
:Norm
:Hi Norm
Adjusting through the range with the Horizontal Frequency Coil effects the image on the screen, but no lock is established. it does have an RC network component in the Sync Seperator circuit btween it and the Vertical Multiplier circuit, however the Horizontal Sync signal is taken off ahead of this network,from the sync seperator directly.
The resistors on the Horizontal Frequency Coil are all right on the money as far as tolerence, and the resistors in the sync seperator circuit are good as well, so I should be looking for a bad capacitor in the sync circuit or Horizontal Frequency Coil Circuit, if I understand you correctly.
Mark
::Hi All
:: Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
::Mark
Do you have sync separator diodes, a 6AL5 or small solid state rectifiers? If you can adjust around 15750 cycles then the sync must not be getting to the circuit.
Norm
::Hi Mark
::
:: A person would need to be looking a the schematic to identify components.
::
:: Can you adjust through the horizontal frequency range and it just doesn't lock? or are out of range? If out of range it's a horizontal oscillator problem. You mentioned adjusting the frequency coil. High resistors in the circuit can increase in value or open. Caps become leaky.
::
:: If it doesn't lock look at sync separator circuit. Resistor and capacitor network along with diodes, tube or solid state.
::
::Norm
::Hi Norm
: Adjusting through the range with the Horizontal Frequency Coil effects the image on the screen, but no lock is established. it does have an RC network component in the Sync Seperator circuit btween it and the Vertical Multiplier circuit, however the Horizontal Sync signal is taken off ahead of this network,from the sync seperator directly.
: The resistors on the Horizontal Frequency Coil are all right on the money as far as tolerence, and the resistors in the sync seperator circuit are good as well, so I should be looking for a bad capacitor in the sync circuit or Horizontal Frequency Coil Circuit, if I understand you correctly.
:Mark
:::Hi All
::: Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
:::Mark
:
: Do you have sync separator diodes, a 6AL5 or small solid state rectifiers? If you can adjust around 15750 cycles then the sync must not be getting to the circuit.
:
:Norm
:Hi Norm
No there are not any sync seperator diodes, only the video detector diode, and the sync seperator tube is a 12AU7.
Mark
:::Hi Mark
:::
::: A person would need to be looking a the schematic to identify components.
:::
::: Can you adjust through the horizontal frequency range and it just doesn't lock? or are out of range? If out of range it's a horizontal oscillator problem. You mentioned adjusting the frequency coil. High resistors in the circuit can increase in value or open. Caps become leaky.
:::
::: If it doesn't lock look at sync separator circuit. Resistor and capacitor network along with diodes, tube or solid state.
:::
:::Norm
:::Hi Norm
:: Adjusting through the range with the Horizontal Frequency Coil effects the image on the screen, but no lock is established. it does have an RC network component in the Sync Seperator circuit btween it and the Vertical Multiplier circuit, however the Horizontal Sync signal is taken off ahead of this network,from the sync seperator directly.
:: The resistors on the Horizontal Frequency Coil are all right on the money as far as tolerence, and the resistors in the sync seperator circuit are good as well, so I should be looking for a bad capacitor in the sync circuit or Horizontal Frequency Coil Circuit, if I understand you correctly.
::Mark
::::Hi All
:::: Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
::::Mark
Check around the sync seperator tube and the path where is goes to the horizontal oscillator.
Norm
::Mark
::
:: Do you have sync separator diodes, a 6AL5 or small solid state rectifiers? If you can adjust around 15750 cycles then the sync must not be getting to the circuit.
::
::Norm
::Hi Norm
: No there are not any sync seperator diodes, only the video detector diode, and the sync seperator tube is a 12AU7.
:Mark
::::Hi Mark
::::
:::: A person would need to be looking a the schematic to identify components.
::::
:::: Can you adjust through the horizontal frequency range and it just doesn't lock? or are out of range? If out of range it's a horizontal oscillator problem. You mentioned adjusting the frequency coil. High resistors in the circuit can increase in value or open. Caps become leaky.
::::
:::: If it doesn't lock look at sync separator circuit. Resistor and capacitor network along with diodes, tube or solid state.
::::
::::Norm
::::Hi Norm
::: Adjusting through the range with the Horizontal Frequency Coil effects the image on the screen, but no lock is established. it does have an RC network component in the Sync Seperator circuit btween it and the Vertical Multiplier circuit, however the Horizontal Sync signal is taken off ahead of this network,from the sync seperator directly.
::: The resistors on the Horizontal Frequency Coil are all right on the money as far as tolerence, and the resistors in the sync seperator circuit are good as well, so I should be looking for a bad capacitor in the sync circuit or Horizontal Frequency Coil Circuit, if I understand you correctly.
:::Mark
:::::Hi All
::::: Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
:::::Mark
:
: Check around the sync seperator tube and the path where is goes to the horizontal oscillator.
:
:Norm
:
:::Mark
:::HI Norm
WIll do, however the output of the sync seperator/Amp goes to the Horizontal AFC before the signal gets to the Horizontal Osc section, 1/2 of the tube is used for AFC where the Horizontal Hold control is tied in and the other half is the OSC section, will let you know if anything turns up, thanks!
Mark
::: Do you have sync separator diodes, a 6AL5 or small solid state rectifiers? If you can adjust around 15750 cycles then the sync must not be getting to the circuit.
:::
:::Norm
:::Hi Norm
:: No there are not any sync seperator diodes, only the video detector diode, and the sync seperator tube is a 12AU7.
::Mark
:::::Hi Mark
:::::
::::: A person would need to be looking a the schematic to identify components.
:::::
::::: Can you adjust through the horizontal frequency range and it just doesn't lock? or are out of range? If out of range it's a horizontal oscillator problem. You mentioned adjusting the frequency coil. High resistors in the circuit can increase in value or open. Caps become leaky.
:::::
::::: If it doesn't lock look at sync separator circuit. Resistor and capacitor network along with diodes, tube or solid state.
:::::
:::::Norm
:::::Hi Norm
:::: Adjusting through the range with the Horizontal Frequency Coil effects the image on the screen, but no lock is established. it does have an RC network component in the Sync Seperator circuit btween it and the Vertical Multiplier circuit, however the Horizontal Sync signal is taken off ahead of this network,from the sync seperator directly.
:::: The resistors on the Horizontal Frequency Coil are all right on the money as far as tolerence, and the resistors in the sync seperator circuit are good as well, so I should be looking for a bad capacitor in the sync circuit or Horizontal Frequency Coil Circuit, if I understand you correctly.
::::Mark
::::::Hi All
:::::: Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
::::::Mark
AAAAAAHHHHAAAAA... the unit which you referred to in the past...but couldn't come up with a chassis # at that time, has now been zeroed in on as circa 55-56-57.
Step one:
Physically locate C64 hoz sync coupling cap and unsolder it from its R56-R57 origin and reposition the floating lead such that it will be tensioned and make a pressing connective fit to the same point it was unsoldered from.
Step two:
Fire up the set and get the best picture that you can and adjust the B1 hoz free run osc adjustment on the rear of the chassis apron.
Analyze the pic and figure how many lines of hoz sync error that you have and adjust B1 until you get progressively wider and fewer lines.
If you are going the WRONG direction you will get even MORE and finer sloping lines !
If this does not even get close to ending up with a single pic...yet with it drifting slowly from side to side.... go to C64 cap and press it aside such that NO hoz sync at all will be coupled in. Try the same procedure and see if you can then get that single slowly hoz / laterally drifting picture with its black dividing blanking bar.
If so... leave the B1 setting as close to a hoz synchronized pic as is possible and then move over to the vert hold and see if in one direction of its adjustment you can get a pic that slowly rolls down...or in turning it in its other direction,a pic that snaps up vertically.
By this point, the separate analysis should have confirmed if you are merely experiencing a hoz osc error, and with it possibly even being beyond the capture range of its companion AFC circuitry...OR... if you also could not get the vert to lock in....albeit looking past the conjunct hoz sync problem being present....it looks like you are having a sync problem.
Feed back time...to see which will be the next step.
Info query....have you "diddled" the companion B2 coil to the back side of the osc coil form, and is it an internal / floating slotted or internal hex ferrite slug OR the same slotted end , brass screw driven slug construction as B1 but being located on the extreme back side of the same coil form ?
Relevant "Tech-in-imus- Ref-er-encimus" is right........'chere
73's de Edd
::Mark
::
:: Check around the sync seperator tube and the path where is goes to the horizontal oscillator.
::
::Norm
::
::::Mark
::::HI Norm
: WIll do, however the output of the sync seperator/Amp goes to the Horizontal AFC before the signal gets to the Horizontal Osc section, 1/2 of the tube is used for AFC where the Horizontal Hold control is tied in and the other half is the OSC section, will let you know if anything turns up, thanks!
:Mark
:::: Do you have sync separator diodes, a 6AL5 or small solid state rectifiers? If you can adjust around 15750 cycles then the sync must not be getting to the circuit.
::::
::::Norm
::::Hi Norm
::: No there are not any sync seperator diodes, only the video detector diode, and the sync seperator tube is a 12AU7.
:::Mark
::::::Hi Mark
::::::
:::::: A person would need to be looking a the schematic to identify components.
::::::
:::::: Can you adjust through the horizontal frequency range and it just doesn't lock? or are out of range? If out of range it's a horizontal oscillator problem. You mentioned adjusting the frequency coil. High resistors in the circuit can increase in value or open. Caps become leaky.
::::::
:::::: If it doesn't lock look at sync separator circuit. Resistor and capacitor network along with diodes, tube or solid state.
::::::
::::::Norm
::::::Hi Norm
::::: Adjusting through the range with the Horizontal Frequency Coil effects the image on the screen, but no lock is established. it does have an RC network component in the Sync Seperator circuit btween it and the Vertical Multiplier circuit, however the Horizontal Sync signal is taken off ahead of this network,from the sync seperator directly.
::::: The resistors on the Horizontal Frequency Coil are all right on the money as far as tolerence, and the resistors in the sync seperator circuit are good as well, so I should be looking for a bad capacitor in the sync circuit or Horizontal Frequency Coil Circuit, if I understand you correctly.
:::::Mark
:::::::Hi All
::::::: Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
:::::::Mark
:
:
:
:AAAAAAHHHHAAAAA... the unit which you referred to in the past...but couldn't come up with a chassis # at that time, has now been zeroed in on as circa 55-56-57.
:
:
:
:Step one:
:
:Physically locate C64 hoz sync coupling cap and unsolder it from its R56-R57 origin and reposition the floating lead such that it will be tensioned and make a pressing connective fit to the same point it was unsoldered from.
:
:
:
:Step two:
:
:Fire up the set and get the best picture that you can and adjust the B1 hoz free run osc adjustment on the rear of the chassis apron.
:Analyze the pic and figure how many lines of hoz sync error that you have and adjust B1 until you get progressively wider and fewer lines.
:If you are going the WRONG direction you will get even MORE and finer sloping lines !
:
:If this does not even get close to ending up with a single pic...yet with it drifting slowly from side to side.... go to C64 cap and press it aside such that NO hoz sync at all will be coupled in. Try the same procedure and see if you can then get that single slowly hoz / laterally drifting picture with its black dividing blanking bar.
:If so... leave the B1 setting as close to a hoz synchronized pic as is possible and then move over to the vert hold and see if in one direction of its adjustment you can get a pic that slowly rolls down...or in turning it in its other direction,a pic that snaps up vertically.
:
:
:
:By this point, the separate analysis should have confirmed if you are merely experiencing a hoz osc error, and with it possibly even being beyond the capture range of its companion AFC circuitry...OR... if you also could not get the vert to lock in....albeit looking past the conjunct hoz sync problem being present....it looks like you are having a sync problem.
:
:Feed back time...to see which will be the next step.
:
:Info query....have you "diddled" the companion B2 coil to the back side of the osc coil form, and is it an internal / floating slotted or internal hex ferrite slug OR the same slotted end , brass screw driven slug construction as B1 but being located on the extreme back side of the same coil form ?
:Hi Edd
From the steps you state, and the image I get on the screen, it appears to be pointing towards a Sync problem.
Mark
:
:
:Relevant "Tech-in-imus- Ref-er-encimus" is right........'chere
:
:
:
:
:73's de Edd
:
:
:
:
:
:
:
:::Mark
:::
::: Check around the sync seperator tube and the path where is goes to the horizontal oscillator.
:::
:::Norm
:::
:::::Mark
:::::HI Norm
:: WIll do, however the output of the sync seperator/Amp goes to the Horizontal AFC before the signal gets to the Horizontal Osc section, 1/2 of the tube is used for AFC where the Horizontal Hold control is tied in and the other half is the OSC section, will let you know if anything turns up, thanks!
::Mark
::::: Do you have sync separator diodes, a 6AL5 or small solid state rectifiers? If you can adjust around 15750 cycles then the sync must not be getting to the circuit.
:::::
:::::Norm
:::::Hi Norm
:::: No there are not any sync seperator diodes, only the video detector diode, and the sync seperator tube is a 12AU7.
::::Mark
:::::::Hi Mark
:::::::
::::::: A person would need to be looking a the schematic to identify components.
:::::::
::::::: Can you adjust through the horizontal frequency range and it just doesn't lock? or are out of range? If out of range it's a horizontal oscillator problem. You mentioned adjusting the frequency coil. High resistors in the circuit can increase in value or open. Caps become leaky.
:::::::
::::::: If it doesn't lock look at sync separator circuit. Resistor and capacitor network along with diodes, tube or solid state.
:::::::
:::::::Norm
:::::::Hi Norm
:::::: Adjusting through the range with the Horizontal Frequency Coil effects the image on the screen, but no lock is established. it does have an RC network component in the Sync Seperator circuit btween it and the Vertical Multiplier circuit, however the Horizontal Sync signal is taken off ahead of this network,from the sync seperator directly.
:::::: The resistors on the Horizontal Frequency Coil are all right on the money as far as tolerence, and the resistors in the sync seperator circuit are good as well, so I should be looking for a bad capacitor in the sync circuit or Horizontal Frequency Coil Circuit, if I understand you correctly.
::::::Mark
::::::::Hi All
:::::::: Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
::::::::Mark
A further evaluation of circuitry utilization and its basic design reveals the unit is not incorporating a mehanical AGC control, thereby , no associative possibility of your problem merely being a grossly misadjustment of same, such that your resultant developed sync output is clipped or severely distorted.
Soooo referring to the new schema with the sync flow markeed up:
Initially confirm that the video peaking coils have not had a galvanic or corrosive effect to their wire termini to the resistors that they are wound upon such that connectivity is broken and there is a 1 meg load presented to the circuitry vice the low value resistance of the parallel inductor.
Then note the (green channel referenced) common flow path of the tapped off video down to the C57 cap that couples into the sync sep V8-A section . At that point the selective biasing of that stage is differentiating between the unwanted video information and the distinct and repetetive vert and hoz syn pulses married within the video information. Dedicated R/C networks further block out the video and reinforce the sync elements as the signal flow works over to the V8-B sync amp section. At its plate section the amplified combo of vert and hoz sync info is routed out and sent over to a low Z path to the right... to the vert sync input point of the K1 vertical integrator, where a further cleaning up of that string of 60~ pulses is accomplished.
Additionally, at the sync amps plate, there is a downward routing of the hoz sync pulse train thru a hi z loop and down eventually to the C64 coupling cap into the hoz AFC comparator circuitry with its string of 15,734 ~ hoz pulses .
What you mentioned was your meticulous trimming in of the hoz and vertical adjustments and was unable to attain NEITHER vert or hoz sync, which would be viewed as a totally free drifting of a sole picture, in any and all directons. Right ? With the qualifying condition that you COULD attain only one complete picture frame floating about. If so.... that is definitive of your two oscillators (V and H ) being capable of tuning to their required frequencies, but merely lacking the repetetive and corrresponding sync nudges of correction to hold them to the required stable frequencies of operation.
Whereas, if there was some degree of sync being present , the pic would show some stability of left to right movement or up and down movement .
You would now want to try another 12AU7....should one be available or could be borrowed from an old tube generation audio amp..guitar amp...radio etc. A test purposes sub could also be a 12AX7, 12AT7, 12AV7.
After that take a Hi-z.....minumal loading effect ..... VTVM, DVM, FET-VM and check and compare the plate and grid voltages on the sync tube , as is supplied on the accompanying schematic, as well as checking for plate resistors, grid resistors and condensers (ceramic types usually trouble free...old paper style ...check 'em ) associated with those stages. Confirm the raw B+ supply voltages to those sections.
ZUJ'ing for feedback...
Tech referencing .........Schematicus deux....[ X ]
![[ X ]](http://img235.imageshack.us/img235/2725/olympicschematicusdeuxdz7.jpg){kind=link}
73's de Edd
::
::
::
::
::AAAAAAHHHHAAAAA... the unit which you referred to in the past...but couldn't come up with a chassis # at that time, has now been zeroed in on as circa 55-56-57.
::
::
::
::Step one:
::
::Physically locate C64 hoz sync coupling cap and unsolder it from its R56-R57 origin and reposition the floating lead such that it will be tensioned and make a pressing connective fit to the same point it was unsoldered from.
::
::
::
::Step two:
::
::Fire up the set and get the best picture that you can and adjust the B1 hoz free run osc adjustment on the rear of the chassis apron.
::Analyze the pic and figure how many lines of hoz sync error that you have and adjust B1 until you get progressively wider and fewer lines.
::If you are going the WRONG direction you will get even MORE and finer sloping lines !
::
::If this does not even get close to ending up with a single pic...yet with it drifting slowly from side to side.... go to C64 cap and press it aside such that NO hoz sync at all will be coupled in. Try the same procedure and see if you can then get that single slowly hoz / laterally drifting picture with its black dividing blanking bar.
::If so... leave the B1 setting as close to a hoz synchronized pic as is possible and then move over to the vert hold and see if in one direction of its adjustment you can get a pic that slowly rolls down...or in turning it in its other direction,a pic that snaps up vertically.
::
::
::
::By this point, the separate analysis should have confirmed if you are merely experiencing a hoz osc error, and with it possibly even being beyond the capture range of its companion AFC circuitry...OR... if you also could not get the vert to lock in....albeit looking past the conjunct hoz sync problem being present....it looks like you are having a sync problem.
::
::Feed back time...to see which will be the next step.
::
::Info query....have you "diddled" the companion B2 coil to the back side of the osc coil form, and is it an internal / floating slotted or internal hex ferrite slug OR the same slotted end , brass screw driven slug construction as B1 but being located on the extreme back side of the same coil form ?
::Hi Edd
: From the steps you state, and the image I get on the screen, it appears to be pointing towards a Sync problem.
:Mark
::
::
::Relevant "Tech-in-imus- Ref-er-encimus" is right........'chere
::
::
::
::
::73's de Edd
::
::
::
::
::
::
::
::::Mark
::::
:::: Check around the sync seperator tube and the path where is goes to the horizontal oscillator.
::::
::::Norm
::::
::::::Mark
::::::HI Norm
::: WIll do, however the output of the sync seperator/Amp goes to the Horizontal AFC before the signal gets to the Horizontal Osc section, 1/2 of the tube is used for AFC where the Horizontal Hold control is tied in and the other half is the OSC section, will let you know if anything turns up, thanks!
:::Mark
:::::: Do you have sync separator diodes, a 6AL5 or small solid state rectifiers? If you can adjust around 15750 cycles then the sync must not be getting to the circuit.
::::::
::::::Norm
::::::Hi Norm
::::: No there are not any sync seperator diodes, only the video detector diode, and the sync seperator tube is a 12AU7.
:::::Mark
::::::::Hi Mark
::::::::
:::::::: A person would need to be looking a the schematic to identify components.
::::::::
:::::::: Can you adjust through the horizontal frequency range and it just doesn't lock? or are out of range? If out of range it's a horizontal oscillator problem. You mentioned adjusting the frequency coil. High resistors in the circuit can increase in value or open. Caps become leaky.
::::::::
:::::::: If it doesn't lock look at sync separator circuit. Resistor and capacitor network along with diodes, tube or solid state.
::::::::
::::::::Norm
::::::::Hi Norm
::::::: Adjusting through the range with the Horizontal Frequency Coil effects the image on the screen, but no lock is established. it does have an RC network component in the Sync Seperator circuit btween it and the Vertical Multiplier circuit, however the Horizontal Sync signal is taken off ahead of this network,from the sync seperator directly.
::::::: The resistors on the Horizontal Frequency Coil are all right on the money as far as tolerence, and the resistors in the sync seperator circuit are good as well, so I should be looking for a bad capacitor in the sync circuit or Horizontal Frequency Coil Circuit, if I understand you correctly.
:::::::Mark
:::::::::Hi All
::::::::: Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
:::::::::Mark
:
:
:
:
:
:A further evaluation of circuitry utilization and its basic design reveals the unit is not incorporating a mehanical AGC control, thereby , no associative possibility of your problem merely being a grossly misadjustment of same, such that your resultant developed sync output is clipped or severely distorted.
:
:Soooo referring to the new schema with the sync flow markeed up:
:Initially confirm that the video peaking coils have not had a galvanic or corrosive effect to their wire termini to the resistors that they are wound upon such that connectivity is broken and there is a 1 meg load presented to the circuitry vice the low value resistance of the parallel inductor.
:
:
:Then note the (green channel referenced) common flow path of the tapped off video down to the C57 cap that couples into the sync sep V8-A section . At that point the selective biasing of that stage is differentiating between the unwanted video information and the distinct and repetetive vert and hoz syn pulses married within the video information. Dedicated R/C networks further block out the video and reinforce the sync elements as the signal flow works over to the V8-B sync amp section. At its plate section the amplified combo of vert and hoz sync info is routed out and sent over to a low Z path to the right... to the vert sync input point of the K1 vertical integrator, where a further cleaning up of that string of 60~ pulses is accomplished.
:Additionally, at the sync amps plate, there is a downward routing of the hoz sync pulse train thru a hi z loop and down eventually to the C64 coupling cap into the hoz AFC comparator circuitry with its string of 15,734 ~ hoz pulses .
:
:
:What you mentioned was your meticulous trimming in of the hoz and vertical adjustments and was unable to attain NEITHER vert or hoz sync, which would be viewed as a totally free drifting of a sole picture, in any and all directons. Right ? With the qualifying condition that you COULD attain only one complete picture frame floating about. If so.... that is definitive of your two oscillators (V and H ) being capable of tuning to their required frequencies, but merely lacking the repetetive and corrresponding sync nudges of correction to hold them to the required stable frequencies of operation.
:Whereas, if there was some degree of sync being present , the pic would show some stability of left to right movement or up and down movement .
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:You would now want to try another 12AU7....should one be available or could be borrowed from an old tube generation audio amp..guitar amp...radio etc. A test purposes sub could also be a 12AX7, 12AT7, 12AV7.
:After that take a Hi-z.....minumal loading effect ..... VTVM, DVM, FET-VM and check and compare the plate and grid voltages on the sync tube , as is supplied on the accompanying schematic, as well as checking for plate resistors, grid resistors and condensers (ceramic types usually trouble free...old paper style ...check 'em ) associated with those stages. Confirm the raw B+ supply voltages to those sections.
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:ZUJ'ing for feedback...
:Hi Edd
Sorry I have not gotten back too you sooner, been very busy lately, I thank you for the info, however I'm afraid I'm going to have to put this one on the back burner for awhile and save it for a cold winter day project, just have too many things going on right now, thanks again and I'll keep you updated.
Mark
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:Tech referencing .........Schematicus deux....[ X ]
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:73's de Edd
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:::AAAAAAHHHHAAAAA... the unit which you referred to in the past...but couldn't come up with a chassis # at that time, has now been zeroed in on as circa 55-56-57.
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:::Step one:
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:::Physically locate C64 hoz sync coupling cap and unsolder it from its R56-R57 origin and reposition the floating lead such that it will be tensioned and make a pressing connective fit to the same point it was unsoldered from.
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:::Step two:
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:::Fire up the set and get the best picture that you can and adjust the B1 hoz free run osc adjustment on the rear of the chassis apron.
:::Analyze the pic and figure how many lines of hoz sync error that you have and adjust B1 until you get progressively wider and fewer lines.
:::If you are going the WRONG direction you will get even MORE and finer sloping lines !
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:::If this does not even get close to ending up with a single pic...yet with it drifting slowly from side to side.... go to C64 cap and press it aside such that NO hoz sync at all will be coupled in. Try the same procedure and see if you can then get that single slowly hoz / laterally drifting picture with its black dividing blanking bar.
:::If so... leave the B1 setting as close to a hoz synchronized pic as is possible and then move over to the vert hold and see if in one direction of its adjustment you can get a pic that slowly rolls down...or in turning it in its other direction,a pic that snaps up vertically.
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:::By this point, the separate analysis should have confirmed if you are merely experiencing a hoz osc error, and with it possibly even being beyond the capture range of its companion AFC circuitry...OR... if you also could not get the vert to lock in....albeit looking past the conjunct hoz sync problem being present....it looks like you are having a sync problem.
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:::Feed back time...to see which will be the next step.
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:::Info query....have you "diddled" the companion B2 coil to the back side of the osc coil form, and is it an internal / floating slotted or internal hex ferrite slug OR the same slotted end , brass screw driven slug construction as B1 but being located on the extreme back side of the same coil form ?
:::Hi Edd
:: From the steps you state, and the image I get on the screen, it appears to be pointing towards a Sync problem.
::Mark
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:::Relevant "Tech-in-imus- Ref-er-encimus" is right........'chere
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:::73's de Edd
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:::::Mark
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::::: Check around the sync seperator tube and the path where is goes to the horizontal oscillator.
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:::::Norm
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:::::::Mark
:::::::HI Norm
:::: WIll do, however the output of the sync seperator/Amp goes to the Horizontal AFC before the signal gets to the Horizontal Osc section, 1/2 of the tube is used for AFC where the Horizontal Hold control is tied in and the other half is the OSC section, will let you know if anything turns up, thanks!
::::Mark
::::::: Do you have sync separator diodes, a 6AL5 or small solid state rectifiers? If you can adjust around 15750 cycles then the sync must not be getting to the circuit.
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:::::::Norm
:::::::Hi Norm
:::::: No there are not any sync seperator diodes, only the video detector diode, and the sync seperator tube is a 12AU7.
::::::Mark
:::::::::Hi Mark
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::::::::: A person would need to be looking a the schematic to identify components.
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::::::::: Can you adjust through the horizontal frequency range and it just doesn't lock? or are out of range? If out of range it's a horizontal oscillator problem. You mentioned adjusting the frequency coil. High resistors in the circuit can increase in value or open. Caps become leaky.
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::::::::: If it doesn't lock look at sync separator circuit. Resistor and capacitor network along with diodes, tube or solid state.
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:::::::::Norm
:::::::::Hi Norm
:::::::: Adjusting through the range with the Horizontal Frequency Coil effects the image on the screen, but no lock is established. it does have an RC network component in the Sync Seperator circuit btween it and the Vertical Multiplier circuit, however the Horizontal Sync signal is taken off ahead of this network,from the sync seperator directly.
:::::::: The resistors on the Horizontal Frequency Coil are all right on the money as far as tolerence, and the resistors in the sync seperator circuit are good as well, so I should be looking for a bad capacitor in the sync circuit or Horizontal Frequency Coil Circuit, if I understand you correctly.
::::::::Mark
::::::::::Hi All
:::::::::: Well yet another project, unfortunately not going so good. I have been working on restoring this model TV, its done, I have correct high voltage, raster good sound, picking up all the channels, only problem is I can not get the horizontal sync, in other words I have the classic unsyncronized video pattern on the screen, I realize there must be a problem in the sync circuits somewhere, as far as what particular component I do not know, I'm thinking a capacitor bad somewhere in this area, perhaps someone could point out which capacitors in particular I should be concerned with, I have tried adjusting the Horizontal Frequency Control as per the SAMS Schematic Procedure, but with no luck, any help would greatly be appreciated.
::::::::::Mark