My CTC-16XL Project.

[Yamamaya42]

example, if i check a 560k res (10% tol ) and it checks at 617k, just outside of the 10% do I let it slide? or replace to be on the safe side?

using this site to tell me the max high / low for the tol for 10% and 20%

https://www.allaboutcircuits.com/too...de-calculator/

so far, if has been close to the high or low side of failing i am replacing.

[old_tv_nut]

Your meter could easily be off much more than the difference between 616 and 617, so you should accept it as OK.

[Rocket]

Originally Posted by Yamamaya42

example, if i check a 560k res (10% tol ) and it checks at 617k, just outside of the 10% do I let it slide? or replace to be on the safe side?

using this site to tell me the max high / low for the tol for 10% and 20%

https://www.allaboutcircuits.com/too...de-calculator/

so far, if has been close to the high or low side of failing i am replacing.

Ive been wondering the same thing as well. and so far if I come across one that is close or at the max, I figured it has drifted up this much may as well get it now than when it does drift out more causing a problem.

man I like that link btw! I've been doing color codes and tolerance by hand gah! lol

[Yamamaya42]

Originally Posted by Rocket

Ive been wondering the same thing as well. and so far if I come across one that is close or at the max, I figured it has drifted up this much may as well get it now than when it does drift out more causing a problem.

man I like that link btw! I've been doing color codes and tolerance by hand gah! lol

I'm thinking the same, After all, I got this box of brand new 2% resistors, and I DO measure them before I put them in.

I have 2 new digital meters, ( cheap ) I only got the 2nd one because the 1st did not have autorange and only went up as high as 20m, new one goes up to 200m.
Checking a removed resistor measures almost the same on both meters, ( less than 1-2% difference )
Also, when I take the removed resistors (after I replace them ) to work an tested with the high $$$ fluke, which is required to get calibrated every year, I get virtually the same results.
So, given that the set is over 50 years old, and that most resistors are of 10% or 20% how critical of an eye should on on for checking them to be on target?

[Electronic M]

If they are barely inside tolerance I leave them if the circuit works and change them if it doesn't... especially if it is something tuned that I rather try retuning by resistor than alignment...

[Yamamaya42]

Another out of the blue question, I have noticed that on the SAMS for the CTC-16xl, there is also a cathode current listing for the vert output, (38ma) , much like the listing for the horz, but can find no reference for testing it, is this something that does not even have to be looked at? As in its not as important as horz cathode current test and setup?

[Electronic M]

The vertical output transformers in most RCA roundy colors tend to be very robust and I can't recall any account of a restorer finding a bad one...VS flybacks that tend to be an above average failure point on RCAs....
If it we're a Zenith 25MC chassis or there about I say the fly you barely have to worry about but the vertical you want to watch.

In RCAs I regard the vertical current spec as a diagnostic tool for vertical problems rather than a needed adjustment...also if it is wrong you would either have to change components or adjust controls to points that may not give correct very sweep.

There's nothing wrong with checking the vertical in your set if you feel inclined.

[Yamamaya42]

I was just curious, like Rocket, I too am having problems getting full Vert height, but I have not really addressed that yet, I will after I can get color working through the IF.
I have just only NOW replaced the ugly c4 (50uf) that was on the sweep pcb, now under the pcb, cause I was working in the area as I was checking the AGC/ SYNC SEP area.

[Rocket]

Originally Posted by Electronic M

If they are barely inside tolerance I leave them if the circuit works and change them if it doesn't... especially if it is something tuned that I rather try retuning by resistor than alignment...

I wonder if that's what I did

[Yamamaya42]

Originally Posted by Rocket

I wonder if that's what I did

my fear is that once that I go through the IF board and check the resistors. that I will still have a IF problem...
and have no setup to align it with
As mentioned, I have no idea what was done to it before I got it T_T

[Rocket]

yeah, I fear I may need to do an alignment also. I have not done one on a TV before and I don't have a sweep gen as well.

and speaking of that, I was going to ask you if your IF section has the shield on the underside? thought of it when I seen mine and was not sure if you were missing the bottom as well

[Yamamaya42]

Originally Posted by Rocket

yeah, I fear I may need to do an alignment also. I have not done one on a TV before and I don't have a sweep gen as well.

and speaking of that, I was going to ask you if your IF section has the shield on the underside? thought of it when I seen mine and was not sure if you were missing the bottom as well

Yes, I DO have that one, which I have removed for the time being , was not easy... took a LOT of heat!

[Rocket]

Well that is some good news : D maybe they didn't mess around too much in there then

[Yamamaya42]

Originally Posted by Rocket

Well that is some good news : D maybe they didn't mess around too much in there then

well, if they messed with the coils, which are tuned from the top, who knows what kind of a mess they made :/

[Rocket]

Originally Posted by Yamamaya42

well, if they messed with the coils, which are tuned from the top, who knows what kind of a mess they made :/

yeah forgot the coils indeed :/