ctc12 clone beam current

[timmy]

the focus voltage in my sams states 4-4.5kv and all i get is just under 4kv but does go up alittle more after warming up and the pic is good.

[timmy]

from top to bottom the sams show the volts at the crt 290v
185v
620v
660
680v

[timmy]

should have a you tube dynamite party with this set the crt will be the best part of the show, lol, lol...

[Bill R]

Just happen to have a CTC12 chassis sitting in the living room floor. Imagine that. Here are a few pictures of the flyback area. What chassis is the silvertone and which sams is it in so I can pull it and look. The screen controls usually have B+Boost on one end and B+ on the other. So the screen voltage will be somewhere between the two.

[timmy]

the chassis is a ctc12 clone 528.61115 and it looks just like these pics you have posted. the sams i have is set 655 folder 2 .

[Username1]

With you two guys and the same chassis sitting in front of you, I think there is something
in the L 105, L106 might be bad but the Eff. circuit is working so I'm not 100% on that
anymore.... But I still can't rule out an honest mistake in wiring the Horiz Output windings
that take off for the B+ Boost.... You guys should compare connection points and see
if something can be tracked down..... C 115 and C 116 were checked..or replaced....?

Bill if you would be so good as to post a few shots of those connection points from the fly
to the Boost supply, back to the damper, maybe Timmy can see something maybe was missed....

With most of the adjustment coils still doing something, and the set producing a watchable
picture, it's gotta be something small, overlooked....

.

[timmy]

Originally Posted by Username1

With you two guys and the same chassis sitting in front of you, I think there is something
in the L 105, L106 might be bad but the Eff. circuit is working so I'm not 100% on that
anymore.... But I still can't rule out an honest mistake in wiring the Horiz Output windings
that take off for the B+ Boost.... You guys should compare connection points and see
if something can be tracked down..... C 115 and C 116 were checked..or replaced....?

Bill if you would be so good as to post a few shots of those connection points from the fly
to the Boost supply, back to the damper, maybe Timmy can see something maybe was missed....

With most of the adjustment coils still doing something, and the set producing a watchable
picture, it's gotta be something small, overlooked....

.

the pics that were posted i was able to compare all what i did to his chassis and its all correct. both the c 115 and 116 were changed. L105 and 106 both come off the damper and they are not burned or discolored in any way and besides i think if one was open i would have a more obvious problem.

[Username1]

Shorted, or partially - you are right they would not be open....

Sorry Timmy, it's just that overall, the Boost seems to be the thing that could be
out of place, and there is not much to it..... I would even at this point check to be
sure the numbers are correct for the flyback transformer... I would almost be ready
to swap parts one by one from an identical set till I found the problem....

.

[timmy]

even though i didnt clip one end of L105 and 106 and checked ohms they looked ok as far as being discolored and they were not so i left them alone. the flyback is a thordarson fly 273 and it is correct. i think ill take the chassis out at this point and look again for anything. if i had to check boost voltages with the chassis out could i keep the anode wire away from everything should i have to test.

[Username1]

Well, I'm thinking like this.... Chokes, and Capacitors help shape signals, the Boost is
too high-we think, So that leaves some signal out of phase, spike too high, etc, to make
a voltage too high at the screen grid controls, and HV reg- that one we have measured,
and we also see the effects..... So- this all leaves a hand full of parts that could be at fault,
or somehow way off in value, possibly switched etc. before you got it, since it's had this
problem when you got it.... I know you been looking at it for years, but it still leaves
the problem intact, so we're missing something.... Gotta check everything, even if you
take today off, leave it and do it another day.... I know answering questions like
"are you sure the fly is the right one?" is stupid.... But I Can't think of much else....

At this point I would have to be looking at circuit errors before you began replacing parts
and the errors may still be there because no one thought there could have been a
part in the wrong spot when you started this project....

.

[timmy]

Originally Posted by Username1

Well, I'm thinking like this.... Chokes, and Capacitors help shape signals, the Boost is
too high-we think, So that leaves some signal out of phase, spike too high, etc, to make
a voltage too high at the screen grid controls, and HV reg- that one we have measured,
and we also see the effects..... So- this all leaves a hand full of parts that could be at fault,
or somehow way off in value, possibly switched etc. before you got it, since it's had this
problem when you got it.... I know you been looking at it for years, but it still leaves
the problem intact, so we're missing something.... Gotta check everything, even if you
take today off, leave it and do it another day.... I know answering questions like
"are you sure the fly is the right one?" is stupid.... But I Can't think of much else....

At this point I would have to be looking at circuit errors before you began replacing parts
and the errors may still be there because no one thought there could have been a
part in the wrong spot when you started this project....

.

ok so i guess when i pull the chassis i will use the sams and go over the fly section wiring including again what i did. and at one time when i found the focus wired wrong i did look around for possible mistakes both by me and maybe from others in the past but i didnt find anymore so at this point i dont really know where to start looking besides the flyback area and somewhat beyond that. i do believe to some degree that the hv reg is working but rather something is preventing it from working properly. so i will check the kine pot ohms again just in case i didnt check that and maybe i concentrated on the hv pot but i have alot to check now and until i find something concrtete the chassis will probably remain out of the set. i dont know if the horiz hold control being turned all the way at the time i got the set going and me tweeking the coil on the vert board to correct that range on the hold control would have anything down the line to do with any of this.

[timmy]

i wonder if its possible i may have messed up in the ps capacitors when i recapped it. where do you think if you would have an educated guess as to what cap and voltages i could have messed up on that may give the effects its doing now. i am really grabbing at straws now, lol lol..... i realize now that i never tried this set when i got it i just tore it apart and began recapping and when i was done that was it so i could still be a fault here if i made a mistake, and in a way i hope i did and im able to find it and correct it. and if i did make a mistake in recapping i will never live it down, lol,lol...

[DaveWM]

you could check the B+ and see if its in the 400v range, that would clear the power supply.

when you say you found the focus coil wired "wrong" how was that determined?

did it look orig to the set?

still not clear on why the reg would be pulling ANY current at 19kv if it is that is wrong, would point to a bias issue between the flyback and the B+.

you need to understand how it works, at 19kv the shunt tube should be fully biased off, if its not there is a problem. At some point. Since the boost voltage is used in the grid circuit of the shunt, I would look there. for some reason I think you have term 1 and 2 reversed on the fly. that or something with how the focus coil is connected.

oh and dont just swap the 1 and 2 to see if I am right, just triple check the schematic to see if you have it right.

[Username1]

Well Timmy, there are LOTS of threads here that begin "I recapped this "" and now it
doesn't "" " Mostly those problems are caused by mass replacement, A possible misplaced
lead, wrong part, misread code, improper part, wrong tolerances, multiply any or two of
these things times 15 caps, and a lot of problems....

That aside, you received the set with problems... They remain even after all this time,
If it was miswired, and you didn't know it, or think of it, then it's still there....

It's just gunna take time and a little extra thinking....

I do not think it's the screen pots, not there... Flyback - good possibility. Parts around
it and damper - focus - good possibility....

.

[timmy]

terminal 1 and 2 on the fly that goes to the focus coil i just looked and those 2 terminals are reversed . i made the huge mistake as i didnt even pay attention to those numbers instead i put the coil back the way the old one was. so now the mistake was done by who ever put the provious fly in not only wired the focus recifier wrong which i found and corrected but also had those 2 terminals reversed and i didnt pick up on that until now. omg, could this be the whole problem here ?????