My 630

[Geist]

Hi All;
I have put in the two Resistors, And with both a Bulb and Variac, I have tried the unit.. The Output from the Transformer is fine, but I get really Low voltage, DC out.. From the Resistor Divider, So, I have Checked the voltage on the Rectifier tubes, still low.. Filaments show 3.4 Volts, after taking the Bulb out it was up to 4.7 volts.. So, next, I will Dis-connect the wire from pin 8 and see what the Rectifiers put out by themselves, If it is still Low, then I know it is my Tubes.. And not Bad load, somewhere else.. But, If it is Higher, then, something in the Cap or Load or the diviver section then something is most likely wired wrong..
THANK YOU Marty

[Geist]

Hi All;
At 60 volts input and with the Bulb in place, I get 160 volts Dc Output on pin 8 of the Rectifier.. I have only one Rectifier tube in Place.. I will test each Rectifier individually.. This Proves that something is Bad, Somewhere down the line, from the Rectifier..
THANK YOU Marty

[old_coot88]

Originally Posted by Geist

Hi All;
I have put in the two Resistors, And with both a Bulb and Variac, I have tried the unit.. The Output from the Transformer is fine, but I get really Low voltage, DC out.. From the Resistor Divider, So, I have Checked the voltage on the Rectifier tubes, still low.. Filaments show 3.4 Volts, after taking the Bulb out it was up to 4.7 volts..

With the Bulb out and full line voltage on the primary, what voltage are you seeing on the 6.3V heater supply? Is it signifigantly plus or minus a nominal 6.3 VAC?

...So, next, I will Dis-connect the wire from pin 8 and see what the Rectifiers put out by themselves,

Leave the first filter cap in-circuit so your meter will see pure DC. Or else it will read the averaged-out value of the supply (ie., it will read low). This is assuming you're using an analog meter. A digital meter will go nuts on unfiltered ripple voltage.

If it is still Low, then I know it is my Tubes.. And not Bad load, somewhere else.. But, If it is Higher, then, something in the Cap or Load or the diviver section then something is most likely wired wrong..
THANK YOU Marty

With no load, it will probably read signifigantly higher than nominal. But be sure the first filter cap is rated for the higher voltage.
As an alternative to leaving the first filter cap in-circuit, you could jumper in a cap temporarily. Anywhere upward 10 mf or so would be plenty (with adequate voltage rating).

[Geist]

Hi All;
Old Coot, Thanks for the input.. I have tried all three rectifier tubes by themselves.. At 60 volts plus Bulb input to the transformer, I get about 160 volts from the Rectifier tubes, each checked by itself.. This is with a DMM and no Cap.. There are no other tubes in the Set.. Don't want to create other unwanted problems.. So, next, I will do as you have suggested, Tieing on one cap and so forth at a time, until I find what is pulling things low.. But, this way, at least I know that it is not the Rectifier tube that was causing the problem.. Thanks for your help and suggestions.. More updates, as I work my way thru things.. In answer to your Heater voltage The 5U4 is a 5 Volt tube, and so my readings of 3.4 volts and 4.7 volts were for the Rectifier Tubes, not for the other Heaters, ever though I had in the past check the other Heater voltages before I plugged in the Rectifiers, and they were OK..
THANK YOU Marty

[Geist]

Hi All;
Just a note, I am sure Glad that I used BOTH the Bulb and the Variac for my initial power up, I think it might have saved my Transformers butt as well as mine.. Since the Bulb was glowing brightly, yet not in later tests with just the Rectifier.. Which also shows it had too much load or short..
THANK YOU Marty

[old_coot88]

Originally Posted by Geist

Hi All;
Just a note, I am sure Glad that I used BOTH the Bulb and the Variac for my initial power up, I think it might have saved my Transformers butt as well as mine.. Since the Bulb was glowing brightly, yet not in later tests with just the Rectifier.. Which also shows it had too much load or short..
THANK YOU Marty

What wattage was the Bulb you were using? If it was low wattage (25 or 40 watt) it probably lit fairly bright from the heater load of all the tubes.
Typically, a 'dim bulb' setup will use bulbs of different wattages (something like 25, 40, 75, 100 and maybe 150). A high wattage bulb will barely glow (if at all) at normal current draw whereas lower wattage bulbs will glow brighter at normal draw.

[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.