Hello to all. I am recovering a television set principle or zenith of end 50 of the 60. This taking to me of head, because no longer, vereis, the image encoje in the inferior part of the screen, folding itself and being left the black screen in the part inferior.(recien fitted, but despues of a good stopped short while, almost covers everything) Pense in the vertical exit, I have watched all componenetes of this part, and mayoria leaves altered, but they have been cambiandos by other new ones But the unico that I have obtained is that the synchronisms are stable, and not that when queria saltaba.Los oscilogramas estan well, at least the figures that appear in the oscilloscope they are those that the scheme draws, but if to verify his Yet previous, pense in short between turns of the deflectoras, changing connections of these, but then the compression aparedece in the superior part of the screen, with sure the inverted image rejecting asi the idea of these coils in question. Also I have watched the ohms of the tranasformador exit picture, dandome the exact reading that indicates the scheme. So single I have left two things to watch, and am, uns component strangers which they seem condensing and in the scheme they paint like resistance, that as a pureba have been replaced by condensers, appearing an image but plegada.y the other, the final valve of exit picture, that from a first moment was put in the tester, giving a low reading, without leaving the green thing, (sin to arrive almost at the yellow part of the comprobador)pero clearing it. this valve is a 6EA7 and under i point of view, if she will be really low, the image encogeria by both sides, (arriba and down) I do not have another one, if tubiere, already had changed it to see. Please, to give your advice me, Sera this valve the cause? and if no, that podria to be? A greeting, Antonio.

Que Paaaaaaaaaaaaaasssssssssa?
OK, kicking into my Spanish-Gringo conversion mode…… I interpret that you are trying to restore a 50-60’s vintage Zenith TV. And its giving you one BIG headache. You are experiencing vertical fold over at the bottom of the screen and an under swept bottom of the picture. You are thinking the problem is in the vertical output section. You have changed just about all of the parts in that section with the only improvement being a well synced pic , but still with the deficient vertical deflection. You were also thinking of the possibility of shorts within one half of the vertical deflection yokes top and bottom coils , so you switched the drive to the coils but the problem showed up at the top of the picture. Therefore with a switching of the effect to the top half, the yoke would not be a valid suspect.You have ohmmed out the vert output transformer and it seems within spec’s as well as scope readings being in agreement with the schematic. You are unsure of two components that you have left.( the R-C vertical integrator couplates, with one in the osc feedback loop and another that couples the vert sync into the vert osc circuit.
You were suspect of your vertical 6EA7 vertical tube with its just marginally good reading , but also thinking that if it was really weak that it would progressively shrink up the picture equally both at the top and bottom of the picture.I think that you said that you didn’t have another…or possibly had one but don’t have a third? So do we really think that the tube could be the fault?

Now the main question to research from is, what is the model and chassis number of the Zenith??

73’s de Edd

_____________________________________________________

:Hello to all. I am recovering a television set principle or zenith of end 50 of the 60. This taking to me of head, because no longer, vereis, the image encoje in the inferior part of the screen, folding itself and being left the black screen in the part inferior.(recien fitted, but despues of a good stopped short while, almost covers everything) Pense in the vertical exit, I have watched all componenetes of this part, and mayoria leaves altered, but they have been cambiandos by other new ones But the unico that I have obtained is that the synchronisms are stable, and not that when queria saltaba.Los oscilogramas estan well, at least the figures that appear in the oscilloscope they are those that the scheme draws, but if to verify his Yet previous, pense in short between turns of the deflectoras, changing connections of these, but then the compression aparedece in the superior part of the screen, with sure the inverted image rejecting asi the idea of these coils in question. Also I have watched the ohms of the tranasformador exit picture, dandome the exact reading that indicates the scheme. So single I have left two things to watch, and am, uns component strangers which they seem condensing and in the scheme they paint like resistance, that as a pureba have been replaced by condensers, appearing an image but plegada.y the other, the final valve of exit picture, that from a first moment was put in the tester, giving a low reading, without leaving the green thing, (sin to arrive almost at the yellow part of the comprobador)pero clearing it. this valve is a 6EA7 and under i point of view, if she will be really low, the image encogeria by both sides, (arriba and down) I do not have another one, if tubiere, already had changed it to see. Please, to give your advice me, Sera this valve the cause? and if no, that podria to be? A greeting, Antonio.

Hello Edd. pardon by my badly understanding of the English. thanks for your answer. O.K., you say it well, I have a failure in vertical in a television set zenith F-2737- model I have replaced all the components of vertical, (resistance and condensers) but not a capacitor stranger of three connections and that in the designated scheme this with K2, and I have not changed the tube, that this to a 60% of its yield. In my country, Spain, does not know this capacitor, and they advise to me that it replaces by a combination of resistor and capacitor, as shows the diagram.

http://img160.imageshack.us/my.php?image=zenithedit8ul.jpg

When doing this substitution, the image arrives at the inferior end, but now it appears badly a synchronism of vertical. That component stranger is this? in he can ***reflx mng “87”. Request me expliqueis and me aconsejeis, I have restuarado numerous old television sets but all European, and not conocia this American typical component. in this diereccion podeis to follow it in a Spanish forum.

http://elvalvulas.com/forum/viewtopic.php?t=2763

greetings from Spain (Europe) Here a friend yours, Antonio

Ayyy Antonio, Espana !...creo de Mejico.
Those Zenith K1 and K2 are "couplates" made by Centralab and Sprague in the US and are a series resistor with shunting capacitors to the side.They resemble a disc ceramic capacitor and with the 87-4 and 87-5 designations are marked with a splash of yellow/4 or green/5 paint on their sides for color coding.
As far as the full sweep , I would check to see if replacing the electrolytic capacitor at the cathode of the output tube would improve the sweep problem. Also check to see if the boost supply voltage at the pin 2 of the LOPT transfor mer is up to the ~640 volt range. Notice that there is a capacitor that connects over to the main B+ line and if there is any leakage in that capacitor it will pull down the boost voltage and cause vertical problems.Your schema shows part of the circuit of one of the vertical couplates at the bottom of the page but all of its equivalent values do not show . It looks as if only one resistor and one capacitor is used, while I remember it being a capacitor to ground, a series resistor and another capacitor to ground. If you are duplicating the couplate in the series feed back loop in the grid to plate of the vert circuit, that would cause your frequency to be off if the correct values were not substituted in when making a discrete duplicate of the couplate.
Ahora....despues cinquenta anos de estudiarlo...en la lengua de Espana.

Eso el "Zenith" K1 y K2 es "couplates" hechos por Centralab y Sprague en los E.E.U.U. y es un resistor de la serie con los condensadores de desvío al side.They se asemeja a un condensador de cerámica del disco y con las 87-4 y 87-5 designaciones están marcados con un chapoteo de la pintura yellow/4 o green/5 en sus lados para la codificación de color. Hasta el barrido completo, comprobaría para ver si substituir el condensador electrolítico en el cátodo del tubo de la salida mejoraría el problema del barrido. También compruebe para ver si el voltaje de fuente del alza en el perno 2 del mer del transfor de LOPT está hasta la gama de voltio ~640. Note que hay un condensador que conecta encima con la línea principal de B+ y si hay alguna salida en que el condensador él tirará hacia abajo el voltaje del alza y causará la pieza vertical de las demostraciones del esquema de problems.Your del circuito de uno de los couplates verticales en el fondo de la página pero todos sus valores equivalentes no demuestren. Mira como si solamente un resistor y un condensador se utilice, mientras que lo recuerdo ser un condensador a moler, un resistor de la serie y otro condensador para moler. Si usted está duplicando el couplate en la serie retroactúe el lazo en la rejilla a la placa del circuito del vert, de que haría su frecuencia ser apagado si los valores correctos no fueron substituidos adentro al hacer un duplicado discreto del couplate.

73's de Edd

Edd thanks for your explanation of this reactance K1 and K2. I have found the tension to booster low, just by 550V and not 600V, after finding capacitor C59 with flights, has raised 577V but the image follows compressed in vertical. I have acquired a new tube 6EA7 to clear doubts, but it will take in receiving it. I have many but European, in the vertical section I work with PCL85, PCL805 I am sure that the failure this in the zone of horizontal. I request your opinions and advice please. A greeting, Antonio.