miniman82
08-06-2017, 03:21 PM
I'm man enough to admit when I'm licked, so here goes. Been working on this clone for a while now, but still can't figure out the horizontal circuit. Most of it seems to follow the original 630 schematic till you get to the damper and flyback, then all hell breaks loose. The fly is not what you normally find in a 630 chassis, it's been swapped out for something else so it could drive a 21" picture tube. The number on the fly is 235T1, which still seems to be an RCA part number but it's a fly for a wider deflection angle and also higher anode voltage set.
How it's wired makes absolutely no sense, so I'm stuck without a schematic. I mean there's wires from the fly that tie into the 6W4 damper heater (WTF?), capacitively coupled horizontal deflection but then there's no means of centering the picture since there doesn't seem to be a centering pot, the thing is a real rubix cube.
Right now I have the correct drive waveform going to the 6CD6 grid, around 120v P-P, the grid bias seems close to what it should be (cathode is 40v over the grid), but I can't get more than 1.2kv out of it no matter what I do. Post recap I did have to futz with the value of a timing cap on the horizontal oscillator to get the required 15,750hz, but other than that it would appear things are doing what they are supposed to do- aside from the fact that there's next to no anode voltage.
Only thing I can figure is either the fly is toast or something is miswired somewhere.
So if you've seen a schematic for a 630 chassis using a non-standard flyback shoot it my way. Otherwise my color wheel set will go on the back burner till I can figure this thing out.
How it's wired makes absolutely no sense, so I'm stuck without a schematic. I mean there's wires from the fly that tie into the 6W4 damper heater (WTF?), capacitively coupled horizontal deflection but then there's no means of centering the picture since there doesn't seem to be a centering pot, the thing is a real rubix cube.
Right now I have the correct drive waveform going to the 6CD6 grid, around 120v P-P, the grid bias seems close to what it should be (cathode is 40v over the grid), but I can't get more than 1.2kv out of it no matter what I do. Post recap I did have to futz with the value of a timing cap on the horizontal oscillator to get the required 15,750hz, but other than that it would appear things are doing what they are supposed to do- aside from the fact that there's next to no anode voltage.
Only thing I can figure is either the fly is toast or something is miswired somewhere.
So if you've seen a schematic for a 630 chassis using a non-standard flyback shoot it my way. Otherwise my color wheel set will go on the back burner till I can figure this thing out.