Confusion about a 5Y3GT rectifier

[mossmamc]

I'm looking at the data sheet for my rectifier tube and something is confusing me. It says it has a filament voltage of 5V but it says that it is direct heated and it only uses 4 pins. I thought this meant that you hooked up the high voltage AC to two pins and you got DC on the other two. Where does the filament voltage enter into it?

[llwhtt]

The high voltage AC goes to pins 4 and 6. The filament voltage goes to pins 2 and 8. The filament or heater IS the cathode. Output DC is usually taken off of pin 8.

Craig

[mossmamc]

Originally Posted by llwhtt

The high voltage AC goes to pins 4 and 6. The filament voltage goes to pins 2 and 8. The filament or heater IS the cathode. Output DC is usually taken off of pin 8.

Craig

Ok, so my high voltage line coming from the rectifier would be between pin eight and a common ground. Is this correct?

[Doz]

Tube Power Supplies

Scroll down to the schematic by "Capacitor only with no load"

[llwhtt]

That's correct. Pin 8 will go to your first filter capacitor, choke, fuse, or whatever your power supply requires. On a directly heated rectifier 5Y3, 5U4, etc the B+ can be taken from either pin 2 or pin 8, however if you were to use an indirectly heated rectifier such as a 5AR4/GZ34 the heater connections are still pins 2 & 8 but the cathode is connected to pin 8. So wire your output to pin 8 and you be able to use all of the common rectifiers. Using pin 2 on a 5AR4/GZ34 as the output will still work but usually not done.

Craig

[Eli Duttman]

An additional point, directly heated rectifiers, like the 5Y3 and 5U4, yield the best possible hum performance by taking the B+ from a center tap on the 5 VAC winding. However, types with cathode sleeves, like the 5AR4, yield the best hum performance by taking the B+ from pin 8, where the sleeve is connected.