The circuit used is a sync separator followed by a multi-vibrator and horizontal sweep amplifier.

I have replaced a number of video coupling caps but no go.

Lou

T.

Lou

:Can you get it to do anything else?
:
:T.

Also, if you have checked your circuit over and over, and cannot find trouble (wrong values/connections), make sure that you didn't spray WD-40 in the horizontal sync control (or any other potentiometer associated with the horizontal...or any potentiometer, period, if you wish to obtain good results). If a potentiometer is dirty, you should either just clean it with contact cleaner, and allow it to dry thoroughly, or you should open the control and apply a thin film of di-electric grease to the carbon ONLY (recommended method). Spraying the entire control with WD-40 puts a wet oil film all over everything, and as carbon granules migrate, they get stuck in that film, and create leakage paths. However, in my experience, when my vertical control went haywire due to this, I had no control over the picture. Everything was random. You say that you have definite control of the picture, so your control is probably functioning normally. Disconnect it and test it for proper operation, though, and also test it for leakage between the terminals and the case. Unless the schematic specifies a connection between the terminals and the case, there should be none. Do this for all potentiometers in the horizontal circuit.

If the picture is the wrong size (as well as sync'ed 1/2 frame off), then your horiztontal oscillator doesn't have enough amlitude (width circuitry...may simply be mis-adjusted, though width adjustments can affect horizontal centering), and possibly the wrong frequency. The picture is more likely to be garbled up at the wrong frequency, though at a higher frequency that is double the normal scanning frequency, you can obtain a synchronized picture that is perhaps a frame off, and is definitely narrower (wider if the frequency is 1/2 the normal rate). If the picture is of the correct size, but is 1/2 frame off, then most likely your sync circuitry isn't passing the correct information, because the horizontal oscillator will still be able to produce the correct frequency on its own, but it won't be able to synchronize with the vertical scan properly, and so the picture will be shifted.

Hope this helps a bit. I'm by no means a television expert, but I've worked with my DeWald BT-100 (RCA 630TS), as well as some other televisions, enough to kind of have a grasp of how things work. I also have some ITI Institute correspondence class books that explain television circuitry pretty well. It's amazingly simple and yet amazingly complicated all at the same time. It is interesting what kind of information is present in the video signal, and how it all works so perfectly....even more so because we still use the 1939 technology to this day.

T.

I will check the internal horizontal lock adjustment. Could be that someone turned it too far.

However, it looks like the picture is out of phase, not double-frame ( ie with the center of the frames in the center of the raster).

Lou

:If the picture is 1/2 a frame off, then either your oscillator is oscillating at the wrong frequency, or your sync separator isn't passing the sync signal properly. Horizontal scanning occurs at a much higher frequency than vertical, so the separator should be using a very small value capacitor, as well as some shunting resistors (or chokes) to pass only the high frequencies. If you altered the values of the capacitors or resistors at all, they may pass the wrong frequencies.
:
:Also, if you have checked your circuit over and over, and cannot find trouble (wrong values/connections), make sure that you didn't spray WD-40 in the horizontal sync control (or any other potentiometer associated with the horizontal...or any potentiometer, period, if you wish to obtain good results). If a potentiometer is dirty, you should either just clean it with contact cleaner, and allow it to dry thoroughly, or you should open the control and apply a thin film of di-electric grease to the carbon ONLY (recommended method). Spraying the entire control with WD-40 puts a wet oil film all over everything, and as carbon granules migrate, they get stuck in that film, and create leakage paths. However, in my experience, when my vertical control went haywire due to this, I had no control over the picture. Everything was random. You say that you have definite control of the picture, so your control is probably functioning normally. Disconnect it and test it for proper operation, though, and also test it for leakage between the terminals and the case. Unless the schematic specifies a connection between the terminals and the case, there should be none. Do this for all potentiometers in the horizontal circuit.
:
:If the picture is the wrong size (as well as sync'ed 1/2 frame off), then your horiztontal oscillator doesn't have enough amlitude (width circuitry...may simply be mis-adjusted, though width adjustments can affect horizontal centering), and possibly the wrong frequency. The picture is more likely to be garbled up at the wrong frequency, though at a higher frequency that is double the normal scanning frequency, you can obtain a synchronized picture that is perhaps a frame off, and is definitely narrower (wider if the frequency is 1/2 the normal rate). If the picture is of the correct size, but is 1/2 frame off, then most likely your sync circuitry isn't passing the correct information, because the horizontal oscillator will still be able to produce the correct frequency on its own, but it won't be able to synchronize with the vertical scan properly, and so the picture will be shifted.
:
:Hope this helps a bit. I'm by no means a television expert, but I've worked with my DeWald BT-100 (RCA 630TS), as well as some other televisions, enough to kind of have a grasp of how things work. I also have some ITI Institute correspondence class books that explain television circuitry pretty well. It's amazingly simple and yet amazingly complicated all at the same time. It is interesting what kind of information is present in the video signal, and how it all works so perfectly....even more so because we still use the 1939 technology to this day.
:
:T.

T.

:Thanks Tom
:
:I will check the internal horizontal lock adjustment. Could be that someone turned it too far.
:
:However, it looks like the picture is out of phase, not double-frame ( ie with the center of the frames in the center of the raster).
:
:Lou
:
::If the picture is 1/2 a frame off, then either your oscillator is oscillating at the wrong frequency, or your sync separator isn't passing the sync signal properly. Horizontal scanning occurs at a much higher frequency than vertical, so the separator should be using a very small value capacitor, as well as some shunting resistors (or chokes) to pass only the high frequencies. If you altered the values of the capacitors or resistors at all, they may pass the wrong frequencies.
::
::Also, if you have checked your circuit over and over, and cannot find trouble (wrong values/connections), make sure that you didn't spray WD-40 in the horizontal sync control (or any other potentiometer associated with the horizontal...or any potentiometer, period, if you wish to obtain good results). If a potentiometer is dirty, you should either just clean it with contact cleaner, and allow it to dry thoroughly, or you should open the control and apply a thin film of di-electric grease to the carbon ONLY (recommended method). Spraying the entire control with WD-40 puts a wet oil film all over everything, and as carbon granules migrate, they get stuck in that film, and create leakage paths. However, in my experience, when my vertical control went haywire due to this, I had no control over the picture. Everything was random. You say that you have definite control of the picture, so your control is probably functioning normally. Disconnect it and test it for proper operation, though, and also test it for leakage between the terminals and the case. Unless the schematic specifies a connection between the terminals and the case, there should be none. Do this for all potentiometers in the horizontal circuit.
::
::If the picture is the wrong size (as well as sync'ed 1/2 frame off), then your horiztontal oscillator doesn't have enough amlitude (width circuitry...may simply be mis-adjusted, though width adjustments can affect horizontal centering), and possibly the wrong frequency. The picture is more likely to be garbled up at the wrong frequency, though at a higher frequency that is double the normal scanning frequency, you can obtain a synchronized picture that is perhaps a frame off, and is definitely narrower (wider if the frequency is 1/2 the normal rate). If the picture is of the correct size, but is 1/2 frame off, then most likely your sync circuitry isn't passing the correct information, because the horizontal oscillator will still be able to produce the correct frequency on its own, but it won't be able to synchronize with the vertical scan properly, and so the picture will be shifted.
::
::Hope this helps a bit. I'm by no means a television expert, but I've worked with my DeWald BT-100 (RCA 630TS), as well as some other televisions, enough to kind of have a grasp of how things work. I also have some ITI Institute correspondence class books that explain television circuitry pretty well. It's amazingly simple and yet amazingly complicated all at the same time. It is interesting what kind of information is present in the video signal, and how it all works so perfectly....even more so because we still use the 1939 technology to this day.
::
::T.

I read all three of your replies as definitely being coincident with the problem being Hoz circuit related and not the vertical.

We know that the sync separator aspect is working, in the respect that there is more brute force sync pulse “coercion” required to lock

in the vertical circuit, as compared to the hoz circuit.


I am not going to be able to access the info on that very specific Ray chassis for about another week or two. But you might fill in on some specs

in the interim.

With that unit being circa ’48, was it using a 6SN7 /or/ 12AU7 family tube for the HOZ MSMV, and was a 6H6 /or/ 6AL5 at its front end for an

AFC phase comparator? A very common / like / identical problem about ~5 years forward in design was the failure / imbalance of a set of

selenium phase detector diodes used for that function.

I would query you as to the design of the sets hoz ckt, in the respect of it probably being of the design of having a coarse / serviceman/ tunable

LC tank circuit in the osc plate circuitry with an additional short range /customer/ hoz hold control as an adjustable pot located in the 1st grid

circuitry of the oscillator circuitry.

With your mention of the Hoz blanking bar being visible, can you observe same, and confirm if the bar will swing both sides of center with
adjustment of the hoz hold, and it may require use of the coils slug to get the full range required for this test. At one point the single bar should

flop over and make two large sloping lines, and with further tuning, three should present themselves. This will be increasingly cumulative, as each variant of
60~in difference from the zero frequency of 15,734 is passed. That will be enough now, so reverse your tuning to get back to the initial single

hoz blanking bar and tune to get the pic to fall out of sync in the other freq direction, with the pictures lines flopping over in a 90 deg difference

in angle.

If that can be accomplished, the hoz circuitry has all of the range required of it, and there is merely a shortcoming in the incoming hoz sync

pulse, its phase angle or the sampled hoz osc signal that it is to be compared against in the phase detector section.

To zero in on that I need info from the schematics I mentioned.

In the interim check plate load resistors in the hoz osc ckt for having heated up and changed value or for high value resistors in the osc grid
circuitry having increased in value or leaky capacitors.

73's de Edd

: Lou is there a blanking bar (a black band) in the pic? Is it in a vertical or horizontal direction? If the vertical frequency is way off the pic may lock but you may see a Horizontal bar in the pic. That would be the vertical blanking bar. If the bar is vertical in direction then that is a horizontal sync problem. Sometimes severe misalignment of the vertical height and linearity controls will result in the vertical to lock somewhere mid pic and not at the top where it is suppose to.
:
:
::Thanks Tom
::
::I will check the internal horizontal lock adjustment. Could be that someone turned it too far.
::
::However, it looks like the picture is out of phase, not double-frame ( ie with the center of the frames in the center of the raster).
::
::Lou
::
:::If the picture is 1/2 a frame off, then either your oscillator is oscillating at the wrong frequency, or your sync separator isn't passing the sync signal properly. Horizontal scanning occurs at a much higher frequency than vertical, so the separator should be using a very small value capacitor, as well as some shunting resistors (or chokes) to pass only the high frequencies. If you altered the values of the capacitors or resistors at all, they may pass the wrong frequencies.
:::
:::Also, if you have checked your circuit over and over, and cannot find trouble (wrong values/connections), make sure that you didn't spray WD-40 in the horizontal sync control (or any other potentiometer associated with the horizontal...or any potentiometer, period, if you wish to obtain good results). If a potentiometer is dirty, you should either just clean it with contact cleaner, and allow it to dry thoroughly, or you should open the control and apply a thin film of di-electric grease to the carbon ONLY (recommended method). Spraying the entire control with WD-40 puts a wet oil film all over everything, and as carbon granules migrate, they get stuck in that film, and create leakage paths. However, in my experience, when my vertical control went haywire due to this, I had no control over the picture. Everything was random. You say that you have definite control of the picture, so your control is probably functioning normally. Disconnect it and test it for proper operation, though, and also test it for leakage between the terminals and the case. Unless the schematic specifies a connection between the terminals and the case, there should be none. Do this for all potentiometers in the horizontal circuit.
:::
:::If the picture is the wrong size (as well as sync'ed 1/2 frame off), then your horiztontal oscillator doesn't have enough amlitude (width circuitry...may simply be mis-adjusted, though width adjustments can affect horizontal centering), and possibly the wrong frequency. The picture is more likely to be garbled up at the wrong frequency, though at a higher frequency that is double the normal scanning frequency, you can obtain a synchronized picture that is perhaps a frame off, and is definitely narrower (wider if the frequency is 1/2 the normal rate). If the picture is of the correct size, but is 1/2 frame off, then most likely your sync circuitry isn't passing the correct information, because the horizontal oscillator will still be able to produce the correct frequency on its own, but it won't be able to synchronize with the vertical scan properly, and so the picture will be shifted.
:::
:::Hope this helps a bit. I'm by no means a television expert, but I've worked with my DeWald BT-100 (RCA 630TS), as well as some other televisions, enough to kind of have a grasp of how things work. I also have some ITI Institute correspondence class books that explain television circuitry pretty well. It's amazingly simple and yet amazingly complicated all at the same time. It is interesting what kind of information is present in the video signal, and how it all works so perfectly....even more so because we still use the 1939 technology to this day.
:::
:::T.

Here is a circuit description.

For the record, I can lock the picture vertically correctly, but horizontally, the picture framing ( not the raw sweep - it is centered) is 1/2 a frame off.

The circuit is a sync clipper ( sync separator, 12AU7) followed by a 12SN7 - 1/2 is a "HOR. MULT" and 1/2 is a "HOR AMP". There is only ONE adjustable coil on the chassis for horizontal lock. This works, with the picture locking at 1/2 a frame and the horizontal hold control also works.

One clue - there is an RC network at the input to the HOR MULT that appears to not be there ( i.e. the circuit is not built "to print"). Instead, so far it appears that the series coupling cap into the grid of this tube is tied back to the plate of the sync clipper- in other words two resistors ( one to ground) are missing , and they have coupled back before the series cap that feeds both horizontal and vertical sections. HOWEVER, so far I have assumed that this combination worked, since it appears to have been built that way. ALSO, the 18K load resistor on the grid of the HOR. MULT is 2K .vs 18K in the documentation. I am not sure who is right, not having been there!!!

HOWEVER, in the interim, I will check all the resistors in the HOR circuit. All caps are the mica type, so should be OK??

I would be willing to fax a copy of the schematic to anyone interested - this one is a real poser for me.

Thanks
Lou:
:
:
:
:
:I read all three of your replies as definitely being coincident with the problem being Hoz circuit related and not the vertical.
:
:We know that the sync separator aspect is working, in the respect that there is more brute force sync pulse “coercion” required to lock
:
:in the vertical circuit, as compared to the hoz circuit.
:
:
:I am not going to be able to access the info on that very specific Ray chassis for about another week or two. But you might fill in on some specs
:
: in the interim.
:
:With that unit being circa ’48, was it using a 6SN7 /or/ 12AU7 family tube for the HOZ MSMV, and was a 6H6 /or/ 6AL5 at its front end for an
:
:AFC phase comparator? A very common / like / identical problem about ~5 years forward in design was the failure / imbalance of a set of
:
:selenium phase detector diodes used for that function.
:
:I would query you as to the design of the sets hoz ckt, in the respect of it probably being of the design of having a coarse / serviceman/ tunable
:
:LC tank circuit in the osc plate circuitry with an additional short range /customer/ hoz hold control as an adjustable pot located in the 1st grid
:
:circuitry of the oscillator circuitry.
:
:With your mention of the Hoz blanking bar being visible, can you observe same, and confirm if the bar will swing both sides of center with
: adjustment of the hoz hold, and it may require use of the coils slug to get the full range required for this test. At one point the single bar should
:
:flop over and make two large sloping lines, and with further tuning, three should present themselves. This will be increasingly cumulative, as each variant of
: 60~in difference from the zero frequency of 15,734 is passed. That will be enough now, so reverse your tuning to get back to the initial single
:
:hoz blanking bar and tune to get the pic to fall out of sync in the other freq direction, with the pictures lines flopping over in a 90 deg difference
:
:in angle.
:
:If that can be accomplished, the hoz circuitry has all of the range required of it, and there is merely a shortcoming in the incoming hoz sync
:
:pulse, its phase angle or the sampled hoz osc signal that it is to be compared against in the phase detector section.
:
:To zero in on that I need info from the schematics I mentioned.
:
:
:
:In the interim check plate load resistors in the hoz osc ckt for having heated up and changed value or for high value resistors in the osc grid
: circuitry having increased in value or leaky capacitors.
:
:
:
:73's de Edd
:
:
:
:
:
:
:
:: Lou is there a blanking bar (a black band) in the pic? Is it in a vertical or horizontal direction? If the vertical frequency is way off the pic may lock but you may see a Horizontal bar in the pic. That would be the vertical blanking bar. If the bar is vertical in direction then that is a horizontal sync problem. Sometimes severe misalignment of the vertical height and linearity controls will result in the vertical to lock somewhere mid pic and not at the top where it is suppose to.
::
::
:::Thanks Tom
:::
:::I will check the internal horizontal lock adjustment. Could be that someone turned it too far.
:::
:::However, it looks like the picture is out of phase, not double-frame ( ie with the center of the frames in the center of the raster).
:::
:::Lou
:::
::::If the picture is 1/2 a frame off, then either your oscillator is oscillating at the wrong frequency, or your sync separator isn't passing the sync signal properly. Horizontal scanning occurs at a much higher frequency than vertical, so the separator should be using a very small value capacitor, as well as some shunting resistors (or chokes) to pass only the high frequencies. If you altered the values of the capacitors or resistors at all, they may pass the wrong frequencies.
::::
::::Also, if you have checked your circuit over and over, and cannot find trouble (wrong values/connections), make sure that you didn't spray WD-40 in the horizontal sync control (or any other potentiometer associated with the horizontal...or any potentiometer, period, if you wish to obtain good results). If a potentiometer is dirty, you should either just clean it with contact cleaner, and allow it to dry thoroughly, or you should open the control and apply a thin film of di-electric grease to the carbon ONLY (recommended method). Spraying the entire control with WD-40 puts a wet oil film all over everything, and as carbon granules migrate, they get stuck in that film, and create leakage paths. However, in my experience, when my vertical control went haywire due to this, I had no control over the picture. Everything was random. You say that you have definite control of the picture, so your control is probably functioning normally. Disconnect it and test it for proper operation, though, and also test it for leakage between the terminals and the case. Unless the schematic specifies a connection between the terminals and the case, there should be none. Do this for all potentiometers in the horizontal circuit.
::::
::::If the picture is the wrong size (as well as sync'ed 1/2 frame off), then your horiztontal oscillator doesn't have enough amlitude (width circuitry...may simply be mis-adjusted, though width adjustments can affect horizontal centering), and possibly the wrong frequency. The picture is more likely to be garbled up at the wrong frequency, though at a higher frequency that is double the normal scanning frequency, you can obtain a synchronized picture that is perhaps a frame off, and is definitely narrower (wider if the frequency is 1/2 the normal rate). If the picture is of the correct size, but is 1/2 frame off, then most likely your sync circuitry isn't passing the correct information, because the horizontal oscillator will still be able to produce the correct frequency on its own, but it won't be able to synchronize with the vertical scan properly, and so the picture will be shifted.
::::
::::Hope this helps a bit. I'm by no means a television expert, but I've worked with my DeWald BT-100 (RCA 630TS), as well as some other televisions, enough to kind of have a grasp of how things work. I also have some ITI Institute correspondence class books that explain television circuitry pretty well. It's amazingly simple and yet amazingly complicated all at the same time. It is interesting what kind of information is present in the video signal, and how it all works so perfectly....even more so because we still use the 1939 technology to this day.
::::
::::T.

I do not have my time constant formula memorized, so I cannot tell you what capacitor and resistor values give you what frequencies, but resistors shunted to 'ground' (across the signal) would tend to shunt out the lower frequencies, and keep the bypass capacitor passing only high frequencies (horizontal sync pulses are small in wave length). In my RCA 630TS books it explains in detail the horizontal blanking bar, and what to look for to see if the proper information is present. However, the sync is taken AFTER the last video IF stage (video is not taken from the sync circuitry), so seeing the information present in the blanking bar only says that the information made it through the video circuitry...not through the sync circuitry. Still, if your video circuitry isn't passing the correct bandwidth of frequencies, sync information can be lost (incorrect bandwidth is more likely to affect horizontal picture resolution first, before it affects items much lower in frequency, such as the horizontal sync pulse). In that case the oscillators would not sync even if the sync circuitry was performing well. You should still be able to properly frame the picture by hand, though. If that is not possible, there probably is trouble in the oscillator circuit. You might consider disconnecting the sync output from the oscillator (or try pulling the sync tubes). If the sync circuit is somehow feeding the wrong information to the oscillator, the oscillator might not be able to do what you want it to.

T.

:
:
:I do not have my time constant formula memorized, so I cannot tell you what capacitor and resistor values give you what frequencies, but resistors shunted to 'ground' (across the signal) would tend to shunt out the lower frequencies, and keep the bypass capacitor passing only high frequencies (horizontal sync pulses are small in wave length). In my RCA 630TS books it explains in detail the horizontal blanking bar, and what to look for to see if the proper information is present. However, the sync is taken AFTER the last video IF stage (video is not taken from the sync circuitry), so seeing the information present in the blanking bar only says that the information made it through the video circuitry...not through the sync circuitry. Still, if your video circuitry isn't passing the correct bandwidth of frequencies, sync information can be lost (incorrect bandwidth is more likely to affect horizontal picture resolution first, before it affects items much lower in frequency, such as the horizontal sync pulse). In that case the oscillators would not sync even if the sync circuitry was performing well. You should still be able to properly frame the picture by hand, though. If that is not possible, there probably is trouble in the oscillator circuit. You might consider disconnecting the sync output from the oscillator (or try pulling the sync tubes). If the sync circuit is somehow feeding the wrong information to the oscillator, the oscillator might not be able to do what you want it to.
:
:T.

The first thing that I notice after examining this circa ‘47 creation is that the bean counters must have initially sat down and met with R&D

and initiated the fact that if this new little infant…called TELLY-VISION …really took off, that they were going to be in some real deep

doo-doo….. what with a hunna and ‘lebenteen thousand 50B5’s, 50L6’s, 12AU6’s and 35Z5’s still in the warehouse….soooooo…...
look what they did to remedy that situation .


With your mentioning that the hoz would flop over both ways about 3 bars, tells us that the hoz osc can free run on both directions of about ~100
cycles above or below the required center frequency of 15,734 ~. I was initially questioning that you might have only been able to tune off
frequency a hoz bar or two in one direction….…. but not being able to quite reach up to the center frequency, in the other direction.

Plus we know that there is no fault with the separation of the vert sync-pulses, as well as that some degree of stripped hoz sync pulses ARE reaching

to the 1st grid of the hoz multivibrator tube. Otherwise, there would be just a side-slipping hoz picture when lock in was attempted with the hoz control.

So, it looks like your fault would be attributable to the phase angle that the sync pulse is being introduced to the 1st grid of the hoz MSMV tube.
The whole time period of a hoz saw sweep is in the order of ~62 microseconds and the hoz sync pulse needs to be within ~1/2 of a microseconds coincidence.

There is a link to a large schema with the bulk of the TV circuitry on it…exclusively… the areas of interest… plus… there is a small thumbnail on this page for referencing .
Your point of interest will be the markup at the first grid of the hoz mult triode, check those supplied values to what is shown n the schema, with no
47 pf , or 3.3k or 4.7 k or 180k having been erroneously installed by a previous servicer, where those designated values are shown. Also, if not replaced already, the yellow referenced electrolytics are critical with C7 needing a low ESR value to give a sharp hoz sync pulse, yet it is not so critical on the 60~ vert sync pulse already being successfully created.
The C3 assures that an optimum level Hoz saw waveform is created at V16A and is fed on to the following driver circuitry.


Larger schema…….. LINK ....Mag it on up

Standing by for findings….

73's de Edd

:
::
::
::I do not have my time constant formula memorized, so I cannot tell you what capacitor and resistor values give you what frequencies, but resistors shunted to 'ground' (across the signal) would tend to shunt out the lower frequencies, and keep the bypass capacitor passing only high frequencies (horizontal sync pulses are small in wave length). In my RCA 630TS books it explains in detail the horizontal blanking bar, and what to look for to see if the proper information is present. However, the sync is taken AFTER the last video IF stage (video is not taken from the sync circuitry), so seeing the information present in the blanking bar only says that the information made it through the video circuitry...not through the sync circuitry. Still, if your video circuitry isn't passing the correct bandwidth of frequencies, sync information can be lost (incorrect bandwidth is more likely to affect horizontal picture resolution first, before it affects items much lower in frequency, such as the horizontal sync pulse). In that case the oscillators would not sync even if the sync circuitry was performing well. You should still be able to properly frame the picture by hand, though. If that is not possible, there probably is trouble in the oscillator circuit. You might consider disconnecting the sync output from the oscillator (or try pulling the sync tubes). If the sync circuit is somehow feeding the wrong information to the oscillator, the oscillator might not be able to do what you want it to.
::
::T.

Thanks for the reply!!

I have already replaced the two electrolytics.

However...

C100 ( in the rectangle ) is tied back to the plate of the 12AU7 tube - the two resistors ( one to ground) do not exist in the chassis and the hor osc tube grid bias resistor is a much lower value - 12K I believe.

I will scope in out. I AM confused as to why this circuit looks like it was modified and/or installed a very long time ago ( resistors look the same vintage).
Would the manufacturer have made some circuit change??

Thanks
Lou
:
:
:
:
:
:The first thing that I notice after examining this circa ‘47 creation is that the bean counters must have initially sat down and met with R&D
:
:and initiated the fact that if this new little infant…called TELLY-VISION …really took off, that they were going to be in some real deep
:
:doo-doo….. what with a hunna and ‘lebenteen thousand 50B5’s, 50L6’s, 12AU6’s and 35Z5’s still in the warehouse….soooooo…...
:look what they did to remedy that situation .
:
:
:With your mentioning that the hoz would flop over both ways about 3 bars, tells us that the hoz osc can free run on both directions of about ~100
:cycles above or below the required center frequency of 15,734 ~. I was initially questioning that you might have only been able to tune off
: frequency a hoz bar or two in one direction….…. but not being able to quite reach up to the center frequency, in the other direction.
:
:Plus we know that there is no fault with the separation of the vert sync-pulses, as well as that some degree of stripped hoz sync pulses ARE reaching
:
: to the 1st grid of the hoz multivibrator tube. Otherwise, there would be just a side-slipping hoz picture when lock in was attempted with the hoz control.
:
:So, it looks like your fault would be attributable to the phase angle that the sync pulse is being introduced to the 1st grid of the hoz MSMV tube.
: The whole time period of a hoz saw sweep is in the order of ~62 microseconds and the hoz sync pulse needs to be within ~1/2 of a microseconds coincidence.
:
:There is a link to a large schema with the bulk of the TV circuitry on it…exclusively… the areas of interest… plus… there is a small thumbnail on this page for referencing .
:Your point of interest will be the markup at the first grid of the hoz mult triode, check those supplied values to what is shown n the schema, with no
:47 pf , or 3.3k or 4.7 k or 180k having been erroneously installed by a previous servicer, where those designated values are shown. Also, if not replaced already, the yellow referenced electrolytics are critical with C7 needing a low ESR value to give a sharp hoz sync pulse, yet it is not so critical on the 60~ vert sync pulse already being successfully created.
:The C3 assures that an optimum level Hoz saw waveform is created at V16A and is fed on to the following driver circuitry.
:
:
:Larger schema…….. LINK ....Mag it on up
:
:
:
:
:
:
:
:Standing by for findings….
:
:
:
:
:
:73's de Edd
:
:
:
:
:
:
:
::
:::
:::
:::I do not have my time constant formula memorized, so I cannot tell you what capacitor and resistor values give you what frequencies, but resistors shunted to 'ground' (across the signal) would tend to shunt out the lower frequencies, and keep the bypass capacitor passing only high frequencies (horizontal sync pulses are small in wave length). In my RCA 630TS books it explains in detail the horizontal blanking bar, and what to look for to see if the proper information is present. However, the sync is taken AFTER the last video IF stage (video is not taken from the sync circuitry), so seeing the information present in the blanking bar only says that the information made it through the video circuitry...not through the sync circuitry. Still, if your video circuitry isn't passing the correct bandwidth of frequencies, sync information can be lost (incorrect bandwidth is more likely to affect horizontal picture resolution first, before it affects items much lower in frequency, such as the horizontal sync pulse). In that case the oscillators would not sync even if the sync circuitry was performing well. You should still be able to properly frame the picture by hand, though. If that is not possible, there probably is trouble in the oscillator circuit. You might consider disconnecting the sync output from the oscillator (or try pulling the sync tubes). If the sync circuit is somehow feeding the wrong information to the oscillator, the oscillator might not be able to do what you want it to.
:::
:::T.

Thanks for the reply!!

I have already replaced the two electrolytics.

However...

C100 ( in the rectangle ) is tied back to the plate of the 12AU6 tube - the two resistors ( one to ground) do not exist in the chassis and the hor osc tube grid bias resistor is a much lower value - 12K I believe.

I will scope in out. I AM confused as to why this circuit looks like it was modified and/or installed a very long time ago ( resistors look the same vintage).
Would the manufacturer have made some circuit change??

Thanks
Lou
:
:
:
:
:
:The first thing that I notice after examining this circa ‘47 creation is that the bean counters must have initially sat down and met with R&D
:
:and initiated the fact that if this new little infant…called TELLY-VISION …really took off, that they were going to be in some real deep
:
:doo-doo….. what with a hunna and ‘lebenteen thousand 50B5’s, 50L6’s, 12AU6’s and 35Z5’s still in the warehouse….soooooo…...
:look what they did to remedy that situation .
:
:
:With your mentioning that the hoz would flop over both ways about 3 bars, tells us that the hoz osc can free run on both directions of about ~100
:cycles above or below the required center frequency of 15,734 ~. I was initially questioning that you might have only been able to tune off
: frequency a hoz bar or two in one direction….…. but not being able to quite reach up to the center frequency, in the other direction.
:
:Plus we know that there is no fault with the separation of the vert sync-pulses, as well as that some degree of stripped hoz sync pulses ARE reaching
:
: to the 1st grid of the hoz multivibrator tube. Otherwise, there would be just a side-slipping hoz picture when lock in was attempted with the hoz control.
:
:So, it looks like your fault would be attributable to the phase angle that the sync pulse is being introduced to the 1st grid of the hoz MSMV tube.
: The whole time period of a hoz saw sweep is in the order of ~62 microseconds and the hoz sync pulse needs to be within ~1/2 of a microseconds coincidence.
:
:There is a link to a large schema with the bulk of the TV circuitry on it…exclusively… the areas of interest… plus… there is a small thumbnail on this page for referencing .
:Your point of interest will be the markup at the first grid of the hoz mult triode, check those supplied values to what is shown n the schema, with no
:47 pf , or 3.3k or 4.7 k or 180k having been erroneously installed by a previous servicer, where those designated values are shown. Also, if not replaced already, the yellow referenced electrolytics are critical with C7 needing a low ESR value to give a sharp hoz sync pulse, yet it is not so critical on the 60~ vert sync pulse already being successfully created.
:The C3 assures that an optimum level Hoz saw waveform is created at V16A and is fed on to the following driver circuitry.
:
:
:Larger schema…….. LINK ....Mag it on up
:
:
:
:
:
:
:
:Standing by for findings….
:
:
:
:
:
:73's de Edd
:
:
:
:
:
:
:
::
:::
:::
:::I do not have my time constant formula memorized, so I cannot tell you what capacitor and resistor values give you what frequencies, but resistors shunted to 'ground' (across the signal) would tend to shunt out the lower frequencies, and keep the bypass capacitor passing only high frequencies (horizontal sync pulses are small in wave length). In my RCA 630TS books it explains in detail the horizontal blanking bar, and what to look for to see if the proper information is present. However, the sync is taken AFTER the last video IF stage (video is not taken from the sync circuitry), so seeing the information present in the blanking bar only says that the information made it through the video circuitry...not through the sync circuitry. Still, if your video circuitry isn't passing the correct bandwidth of frequencies, sync information can be lost (incorrect bandwidth is more likely to affect horizontal picture resolution first, before it affects items much lower in frequency, such as the horizontal sync pulse). In that case the oscillators would not sync even if the sync circuitry was performing well. You should still be able to properly frame the picture by hand, though. If that is not possible, there probably is trouble in the oscillator circuit. You might consider disconnecting the sync output from the oscillator (or try pulling the sync tubes). If the sync circuit is somehow feeding the wrong information to the oscillator, the oscillator might not be able to do what you want it to.
:::
:::T.

I think that is what is throwing me off - that the circuit does NOT look like the published schematic, AND it looks like the parts in the circuit are just as old as the ones installed elsewhere!!!!

Sorry for being Mr. Confused!!

Lou

:Edd
:
:Thanks for the reply!!
:
:I have already replaced the two electrolytics.
:
:However...
:
:C100 ( in the rectangle ) is tied back to the plate of the 12AU6 tube - the two resistors ( one to ground) do not exist in the chassis and the hor osc tube grid bias resistor is a much lower value - 12K I believe.
:
:I will scope in out. I AM confused as to why this circuit looks like it was modified and/or installed a very long time ago ( resistors look the same vintage).
:Would the manufacturer have made some circuit change??
:
:
:Thanks
:Lou
::
::
::
::
::
::The first thing that I notice after examining this circa ‘47 creation is that the bean counters must have initially sat down and met with R&D
::
::and initiated the fact that if this new little infant…called TELLY-VISION …really took off, that they were going to be in some real deep
::
::doo-doo….. what with a hunna and ‘lebenteen thousand 50B5’s, 50L6’s, 12AU6’s and 35Z5’s still in the warehouse….soooooo…...
::look what they did to remedy that situation .
::
::
::With your mentioning that the hoz would flop over both ways about 3 bars, tells us that the hoz osc can free run on both directions of about ~100
::cycles above or below the required center frequency of 15,734 ~. I was initially questioning that you might have only been able to tune off
:: frequency a hoz bar or two in one direction….…. but not being able to quite reach up to the center frequency, in the other direction.
::
::Plus we know that there is no fault with the separation of the vert sync-pulses, as well as that some degree of stripped hoz sync pulses ARE reaching
::
:: to the 1st grid of the hoz multivibrator tube. Otherwise, there would be just a side-slipping hoz picture when lock in was attempted with the hoz control.
::
::So, it looks like your fault would be attributable to the phase angle that the sync pulse is being introduced to the 1st grid of the hoz MSMV tube.
:: The whole time period of a hoz saw sweep is in the order of ~62 microseconds and the hoz sync pulse needs to be within ~1/2 of a microseconds coincidence.
::
::There is a link to a large schema with the bulk of the TV circuitry on it…exclusively… the areas of interest… plus… there is a small thumbnail on this page for referencing .
::Your point of interest will be the markup at the first grid of the hoz mult triode, check those supplied values to what is shown n the schema, with no
::47 pf , or 3.3k or 4.7 k or 180k having been erroneously installed by a previous servicer, where those designated values are shown. Also, if not replaced already, the yellow referenced electrolytics are critical with C7 needing a low ESR value to give a sharp hoz sync pulse, yet it is not so critical on the 60~ vert sync pulse already being successfully created.
::The C3 assures that an optimum level Hoz saw waveform is created at V16A and is fed on to the following driver circuitry.
::
::
::Larger schema…….. LINK ....Mag it on up
::
::
::
::
::
::
::
::Standing by for findings….
::
::
::
::
::
::73's de Edd
::
::
::
::
::
::
::
:::
::::
::::
::::I do not have my time constant formula memorized, so I cannot tell you what capacitor and resistor values give you what frequencies, but resistors shunted to 'ground' (across the signal) would tend to shunt out the lower frequencies, and keep the bypass capacitor passing only high frequencies (horizontal sync pulses are small in wave length). In my RCA 630TS books it explains in detail the horizontal blanking bar, and what to look for to see if the proper information is present. However, the sync is taken AFTER the last video IF stage (video is not taken from the sync circuitry), so seeing the information present in the blanking bar only says that the information made it through the video circuitry...not through the sync circuitry. Still, if your video circuitry isn't passing the correct bandwidth of frequencies, sync information can be lost (incorrect bandwidth is more likely to affect horizontal picture resolution first, before it affects items much lower in frequency, such as the horizontal sync pulse). In that case the oscillators would not sync even if the sync circuitry was performing well. You should still be able to properly frame the picture by hand, though. If that is not possible, there probably is trouble in the oscillator circuit. You might consider disconnecting the sync output from the oscillator (or try pulling the sync tubes). If the sync circuit is somehow feeding the wrong information to the oscillator, the oscillator might not be able to do what you want it to.
::::
::::T.

OK on the electrolytics.

Now, by all means, move on down to the hoz integrating network that I had highlighted within the magenta box and build one up by solder tacking those
few …4 ..RC components together and inserting in circuit as is shown.

I can’t see the hoz sampling sourcing being taken from the high level present at the V13 / 12AU6 plate at all, but on down the line as is shown in the schema, that feeds downward from between the .05 and the 4.7K res junction feeding into the vert circuitry.With only an 180K and 220 K on that plate circuitry of V13

Thassit…

Larger schema…….. LINK

Standing by for findings….

73's de Edd

::PPS
:
:I think that is what is throwing me off - that the circuit does NOT look like the published schematic, AND it looks like the parts in the circuit are just as old as the ones installed elsewhere!!!!
:
:Sorry for being Mr. Confused!!
:
:Lou
:
::Edd
::
::Thanks for the reply!!
::
::I have already replaced the two electrolytics.
::
::However...
::
::C100 ( in the rectangle ) is tied back to the plate of the 12AU6 tube - the two resistors ( one to ground) do not exist in the chassis and the hor osc tube grid bias resistor is a much lower value - 12K I believe.
::
::I will scope in out. I AM confused as to why this circuit looks like it was modified and/or installed a very long time ago ( resistors look the same vintage).
::Would the manufacturer have made some circuit change??
::
::
::Thanks
::Lou
:::
:::
:::
:::
:::
:::The first thing that I notice after examining this circa ‘47 creation is that the bean counters must have initially sat down and met with R&D
:::
:::and initiated the fact that if this new little infant…called TELLY-VISION …really took off, that they were going to be in some real deep
:::
:::doo-doo….. what with a hunna and ‘lebenteen thousand 50B5’s, 50L6’s, 12AU6’s and 35Z5’s still in the warehouse….soooooo…...
:::look what they did to remedy that situation .
:::
:::
:::With your mentioning that the hoz would flop over both ways about 3 bars, tells us that the hoz osc can free run on both directions of about ~100
:::cycles above or below the required center frequency of 15,734 ~. I was initially questioning that you might have only been able to tune off
::: frequency a hoz bar or two in one direction….…. but not being able to quite reach up to the center frequency, in the other direction.
:::
:::Plus we know that there is no fault with the separation of the vert sync-pulses, as well as that some degree of stripped hoz sync pulses ARE reaching
:::
::: to the 1st grid of the hoz multivibrator tube. Otherwise, there would be just a side-slipping hoz picture when lock in was attempted with the hoz control.
:::
:::So, it looks like your fault would be attributable to the phase angle that the sync pulse is being introduced to the 1st grid of the hoz MSMV tube.
::: The whole time period of a hoz saw sweep is in the order of ~62 microseconds and the hoz sync pulse needs to be within ~1/2 of a microseconds coincidence.
:::
:::There is a link to a large schema with the bulk of the TV circuitry on it…exclusively… the areas of interest… plus… there is a small thumbnail on this page for referencing .
:::Your point of interest will be the markup at the first grid of the hoz mult triode, check those supplied values to what is shown n the schema, with no
:::47 pf , or 3.3k or 4.7 k or 180k having been erroneously installed by a previous servicer, where those designated values are shown. Also, if not replaced already, the yellow referenced electrolytics are critical with C7 needing a low ESR value to give a sharp hoz sync pulse, yet it is not so critical on the 60~ vert sync pulse already being successfully created.
:::The C3 assures that an optimum level Hoz saw waveform is created at V16A and is fed on to the following driver circuitry.
:::
:::
:::Larger schema…….. LINK ....Mag it on up
:::
:::
:::
:::
:::
:::
:::
:::Standing by for findings….
:::
:::
:::
:::
:::
:::73's de Edd
:::
:::
:::
:::
:::
:::
:::
::::
:::::
:::::
:::::I do not have my time constant formula memorized, so I cannot tell you what capacitor and resistor values give you what frequencies, but resistors shunted to 'ground' (across the signal) would tend to shunt out the lower frequencies, and keep the bypass capacitor passing only high frequencies (horizontal sync pulses are small in wave length). In my RCA 630TS books it explains in detail the horizontal blanking bar, and what to look for to see if the proper information is present. However, the sync is taken AFTER the last video IF stage (video is not taken from the sync circuitry), so seeing the information present in the blanking bar only says that the information made it through the video circuitry...not through the sync circuitry. Still, if your video circuitry isn't passing the correct bandwidth of frequencies, sync information can be lost (incorrect bandwidth is more likely to affect horizontal picture resolution first, before it affects items much lower in frequency, such as the horizontal sync pulse). In that case the oscillators would not sync even if the sync circuitry was performing well. You should still be able to properly frame the picture by hand, though. If that is not possible, there probably is trouble in the oscillator circuit. You might consider disconnecting the sync output from the oscillator (or try pulling the sync tubes). If the sync circuit is somehow feeding the wrong information to the oscillator, the oscillator might not be able to do what you want it to.
:::::
:::::T.

Awfully nice of you to provide all this support.

I have ordered a 12AL5 tube from Antique Electronics Supply. The emission on the old one was just too bad ( i.e. almost none!!).

After I install this diode and prove that the circuit is not functioning because someone hacked it up a long , long time ago, I will rebuild it with the circuit in the schematic ( the input network you mentioned and circled).

Thanks Again
Lou:
:
:
:
:
:OK on the electrolytics.
:
:Now, by all means, move on down to the hoz integrating network that I had highlighted within the magenta box and build one up by solder tacking those
: few …4 ..RC components together and inserting in circuit as is shown.
:
: I can’t see the hoz sampling sourcing being taken from the high level present at the V13 / 12AU6 plate at all, but on down the line as is shown in the schema, that feeds downward from between the .05 and the 4.7K res junction feeding into the vert circuitry.With only an 180K and 220 K on that plate circuitry of V13
:
:Thassit…
:
:
:
:Larger schema…….. LINK
:
:
:
:
:
:Standing by for findings….
:
:
:
:
:
:73's de Edd
:
:
:
:
:
:
:
:
:::PPS
::
::I think that is what is throwing me off - that the circuit does NOT look like the published schematic, AND it looks like the parts in the circuit are just as old as the ones installed elsewhere!!!!
::
::Sorry for being Mr. Confused!!
::
::Lou
::
:::Edd
:::
:::Thanks for the reply!!
:::
:::I have already replaced the two electrolytics.
:::
:::However...
:::
:::C100 ( in the rectangle ) is tied back to the plate of the 12AU6 tube - the two resistors ( one to ground) do not exist in the chassis and the hor osc tube grid bias resistor is a much lower value - 12K I believe.
:::
:::I will scope in out. I AM confused as to why this circuit looks like it was modified and/or installed a very long time ago ( resistors look the same vintage).
:::Would the manufacturer have made some circuit change??
:::
:::
:::Thanks
:::Lou
::::
::::
::::
::::
::::
::::The first thing that I notice after examining this circa ‘47 creation is that the bean counters must have initially sat down and met with R&D
::::
::::and initiated the fact that if this new little infant…called TELLY-VISION …really took off, that they were going to be in some real deep
::::
::::doo-doo….. what with a hunna and ‘lebenteen thousand 50B5’s, 50L6’s, 12AU6’s and 35Z5’s still in the warehouse….soooooo…...
::::look what they did to remedy that situation .
::::
::::
::::With your mentioning that the hoz would flop over both ways about 3 bars, tells us that the hoz osc can free run on both directions of about ~100
::::cycles above or below the required center frequency of 15,734 ~. I was initially questioning that you might have only been able to tune off
:::: frequency a hoz bar or two in one direction….…. but not being able to quite reach up to the center frequency, in the other direction.
::::
::::Plus we know that there is no fault with the separation of the vert sync-pulses, as well as that some degree of stripped hoz sync pulses ARE reaching
::::
:::: to the 1st grid of the hoz multivibrator tube. Otherwise, there would be just a side-slipping hoz picture when lock in was attempted with the hoz control.
::::
::::So, it looks like your fault would be attributable to the phase angle that the sync pulse is being introduced to the 1st grid of the hoz MSMV tube.
:::: The whole time period of a hoz saw sweep is in the order of ~62 microseconds and the hoz sync pulse needs to be within ~1/2 of a microseconds coincidence.
::::
::::There is a link to a large schema with the bulk of the TV circuitry on it…exclusively… the areas of interest… plus… there is a small thumbnail on this page for referencing .
::::Your point of interest will be the markup at the first grid of the hoz mult triode, check those supplied values to what is shown n the schema, with no
::::47 pf , or 3.3k or 4.7 k or 180k having been erroneously installed by a previous servicer, where those designated values are shown. Also, if not replaced already, the yellow referenced electrolytics are critical with C7 needing a low ESR value to give a sharp hoz sync pulse, yet it is not so critical on the 60~ vert sync pulse already being successfully created.
::::The C3 assures that an optimum level Hoz saw waveform is created at V16A and is fed on to the following driver circuitry.
::::
::::
::::Larger schema…….. LINK ....Mag it on up
::::
::::
::::
::::
::::
::::
::::
::::Standing by for findings….
::::
::::
::::
::::
::::
::::73's de Edd
::::
::::
::::
::::
::::
::::
::::
:::::
::::::
::::::
::::::I do not have my time constant formula memorized, so I cannot tell you what capacitor and resistor values give you what frequencies, but resistors shunted to 'ground' (across the signal) would tend to shunt out the lower frequencies, and keep the bypass capacitor passing only high frequencies (horizontal sync pulses are small in wave length). In my RCA 630TS books it explains in detail the horizontal blanking bar, and what to look for to see if the proper information is present. However, the sync is taken AFTER the last video IF stage (video is not taken from the sync circuitry), so seeing the information present in the blanking bar only says that the information made it through the video circuitry...not through the sync circuitry. Still, if your video circuitry isn't passing the correct bandwidth of frequencies, sync information can be lost (incorrect bandwidth is more likely to affect horizontal picture resolution first, before it affects items much lower in frequency, such as the horizontal sync pulse). In that case the oscillators would not sync even if the sync circuitry was performing well. You should still be able to properly frame the picture by hand, though. If that is not possible, there probably is trouble in the oscillator circuit. You might consider disconnecting the sync output from the oscillator (or try pulling the sync tubes). If the sync circuit is somehow feeding the wrong information to the oscillator, the oscillator might not be able to do what you want it to.
::::::
::::::T.

The sync. separator circuitry usually consists of broad frequency filters, much like a tone control network, and is most likely not capable of a phase shift, especially of this nature, so the problem more likely lies in the horizontal detector, oscillator, or amplifier circuitry. If this is a magnetically deflected set, faults in the deflection coils or any paralleling resistors are more likely to cause linearity issues than an otherwise perfect picture that's a 1/2 frame off horizontally.

T.

I noticed you said you replaced a number of coupling caps.. Due to the age of this unit, you have to replace ALL of the paper caps. I have found that 99% of the caps I replaced in this unit were BAD. In fact, my TV works great today BUT I STILL have one or two leftover paper caps in the vertical section that make my picture drift a little vertically after a while. I may replace them in the future.

Also. I can synthesize the 1/2 frame effect by the setting of my horizontal hold control on the front panel.You CAN get 1/2 a frame off OR complete synchronization over say 1/2 a turn on the control.

Incidentally, this sat has a special place in my guest room.

PS I am amazed that you can pull up an old query like this!!

Lou T.

::Would anyone know the reason why my Raytheon TV picture synchronizes 1/2 a frame off?
::
::The circuit used is a sync separator followed by a multi-vibrator and horizontal sweep amplifier.
::
::I have replaced a number of video coupling caps but no go.
::
::Lou
:

I SAID I replaced a number of caps _ I eventually replaced all of them. I hope you did too!!!

Lou
:Don: PS
:
:I noticed you said you replaced a number of coupling caps.. Due to the age of this unit, you have to replace ALL of the paper caps. I have found that 99% of the caps I replaced in this unit were BAD. In fact, my TV works great today BUT I STILL have one or two leftover paper caps in the vertical section that make my picture drift a little vertically after a while. I may replace them in the future.
:
:Also. I can synthesize the 1/2 frame effect by the setting of my horizontal hold control on the front panel.You CAN get 1/2 a frame off OR complete synchronization over say 1/2 a turn on the control.
:
:Incidentally, this sat has a special place in my guest room.
:
:PS I am amazed that you can pull up an old query like this!!
:
:Lou T.
:
:::Would anyone know the reason why my Raytheon TV picture synchronizes 1/2 a frame off?
:::
:::The circuit used is a sync separator followed by a multi-vibrator and horizontal sweep amplifier.
:::
:::I have replaced a number of video coupling caps but no go.
:::
:::Lou
::
:
: