My 630

[Geist]

Hi All;
Old Coot, I have been using a 40 Watt Bulb, But remember I stated I had only two tubes Plugged in Both 5U4's, and at present only One 5U4 is plugged in, I am working my way down the Cap and Choke coil and Cap line.. I am waitng for my Iron to warm up to take out another wire, so I only have Cap Choke and Cap hooked in..
THANK YOU Marty

[old_coot88]

Is there any chance one of the replacement electrolytics could've got installed backwards?
I been looking at the schematic posted by Vts1134 in another thread in another forum. Is this the same schematic you're using? If so, it incorrectly shows C220C with its negative side to ground and its positive side to the negative 100V supply rail. I.e., it's shown backward.
If connected as shown in the schematic, it would definitely be a problem.

[Geist]

Hi All;
Old Coot, Yes, it is the same Schematic.. I cannot take that Cap apart, again it would destroy it.. But, I can unwire that one from ground and install an external Cap.. All three Caps in that Can are wired with common Negative connection..
THANK YOU Marty

[Geist]

Hi All;
All I have at present is one Electrolytic Cap that is 350 Volt at 10 MFD.. It calls for a 150 Volt at 80 MFD.. I could try the 10 MFD just to see If it makes any difference.. While disconnecting the one in the Can.. I am going to look at the old Can and see IF it has that one cap internally wired Backward in reference to the others..
THANK YOU Marty

[Geist]

Hi All;
Old Coot, I just looked at the Can and it has (as near as I can tell) the negative as the common point.. I also, Just looked at the Sams and It also shows that the + (positive) side of that cap going to Ground..
On another Cap the (C225) on the Riders, When C225A is connected to Cap C221B, then the voltage goes LOW, about 45 volts at 120 volt input to the transformer, But when C225 is not connected to C221B, the the Voltage is about 230 volts, still slightly low, by 70 Volts, but that could just be my Rectifier, since they are all old Tubes.. So when C225 is connected either what is connected on the other side of it or the other Cap, Is pulling things down.. I have yet to disconnect the rest of the wires from C225 to see IF it has any affect on the Voltage Dropping..
THANK YOU Marty

[old_coot88]

Originally Posted by Geist

..Yes, it is the same Schematic.. I cannot take that Cap apart, again it would destroy it.. But, I can unwire that one from ground and install an external Cap.. All three Caps in that Can are wired with common Negative connection..

If all three are wired with common negative, that would be correct. AND the common negative should be 'floating' above ground since it is the negative supply rail (or buss). It is floating and not shorted to ground, isn't it? Looks like it should show around 500-600 ohms to ground, with a bit of variation when you turn the focus control.

I just looked at the Can and it has (as near as I can tell) the negative as the common point.. I also, Just looked at the Sams and It also shows that the + (positive) side of that cap going to Ground..

Good. Then Sams has it correct.

On another Cap the (C225) on the Riders, When C225A is connected to Cap C221B, then the voltage goes LOW, about 45 volts at 120 volt input to the transformer, But when C225 is not connected to C221B, the the Voltage is about 230 volts, still slightly low, by 70 Volts, but that could just be my Rectifier, since they are all old Tubes.. So when C225 is connected either what is connected on the other side of it or the other Cap, Is pulling things down.. I have yet to disconnect the rest of the wires from C225 to see IF it has any affect on the Voltage Dropping..

Have you checked the Horz centering and Vert centering controls? Both should be 20 ohms according to the schematic. An open element in either one could really screw things up since they're both in series in the B+ chain feeding out to the 275V buss.

Um.. You are taking your voltage reading at the 275V source, right?

And another thought.. is the center tap of the power xfmr's HV winding connected to the common-negative 100V buss? In re-reading your thread, you mentioned some strangely low B+ readings coming out of the 5U4s. An unconnected or mis-connected center tap could do this.

[Geist]

Hi all;
Old Coot, I guess I am a little mixed up from your previous postings.. I take it that my Cap is OK, and NOT wired Backwards.. From what you have last written..
At present when I am measuring my voltages I have been measuring from Pin 8 of the 5U4 and not from the 275 Volt tap at present.. My DMM is attached to Chassis Ground on one side and pin 8 on the other side.. Since it is connected to something that is causing it to show a low value..
You, may be right in that it could be either Centering pot..
Tomorrow I plan on unhooking all the connections to the negative side and the other cap positive side, to see if the problem still exists, these seem to be the connections to the Centering pots.. Then connecting the other wires on till I find the Culprit that is bringing the whole system down.. This is before it even gets to the 275 Volt tap and so it still could be something that the Tap is tied to and not the centering pots.. So, I have alot of places to check..
And, Yes, the Center tap on the Transformer is connected to C221 Common can side, which is above and Isolated from ground..