slyvania roundie

[DaveWM]

any info on a REA21FKP22? is it just your garden variety roundie, thats a new number to me.

[miniman82]

The 21FKP is electrically the same as all the others, data sheet says grey bonded faceplate just like 21FJP.

http://tubedata.tubes.se/sheets/168/2/21CYP22.pdf

[Glenz75]

Great progress on the set Looking good, always nice to sort out all those niggly things with these old Tv's gives a feeling of satisfaction

[compucat]

The convergence neck components look just like those used in Zenith sets. I expect the crt neck components are interchangeable between brands as long as the picture tube is the same. That is a great picture by the way.

[DaveWM]

thanks, its getting there. I need to fuss with the B&K 1076 and work on the vert and horz lineairity.

The lines seem to spread out a bit on the very top and the horz is not very good, does not show up with out the test pattern.

I will prob scope the grid of the 6GF7 (vert output) and take a look a the waveform, but its so subtle I dont think I will see anything there.

will try a few tube subs there and see if it clears up. I have checked most of the resistors and caps (not the 680pf in the feed back) Everything looks good, no jitters etc... replaced the only resistor in the vert cire that drifed more than 10% a precision 2.2 meg.

it does not have an auto degausser, I have a kit that I may try installing, every time I move it it needs to be degaussed.

[DaveWM]

still fighting that darn tendancy towards line pairing...

[DaveWM]

fooled with it some more, tried some new vert tubes (6GF7), no change. every now and then I can get it to not pair up, but most of the time it does (messing with the vert hold, but its not a very reliable way to get it).

I couple of things noticed. I need to very nearly max out the lin adj (on this set its the one that feeds the plate from the boost, I know on some sets its called the vert height, I dont know why they cant make up their minds on this) to get the linearity as good as I can get it. Also I noticed its a tad jumpy, you can really notice it when there is some text near the top of the screen. I dont know if this "jumpy" vert is tied into the "jumpy" line pairing but it seems like it could be.

While I did test the various caps in the circuit with my old school cap tester the 2kv .0086 cap from the plate of the output side of the multivibrator could not be tested at rated voltage (tester only goes to 450v). there is also some little 680pf disc caps that I am not sure of the function.

I never did scope the grid output from the integrater the way the sams said to (bright down, tube out) to look for excessive horz hash.

I think I mentioned before the last tough dog line pairing issue I had was on a B&W maggie, it was from the yoke, some how it was getting horz back thru vert out transformer and back into the vert osc. I only found it by comparing a working set to the bad set and seeing all the hash on the bad set secondary.

I have another CTC-16 (this is a clone) so I could do the same, or just try a different yoke (I have an NOS). Its really a pita as the rest of the pic looks fine.

I dont know if the boost voltage could be causing this (if it had hash on it from a bad cap). I think I checked it, but not sure. again I could prob scope the it and see, again not being experienced in this I would need to look at a working set to see what it should look like...