03-24-2019, 04:01 PM
>I notice that for some reason, they ground one side of the filament voltage winding
Couple of fine points. In a vacuum tube w/o a cathode the thingy that lights up is called the filament. If the tube has a cathode the thingy that lights up is called a heater.
Old skool sets that use filament or directly heated tube you will rarely find one side the filament grounded. What you will find is the filament winding will have a ct and at this point the ct acts as the cathode connection. Sometimes the ct is grounded but more often than not the ct is connected to a bias source.
On tube w/a cathode aka indirectly heated tubes, the reason for the one side being grounded is simple. It saves time and wire when construction.
GL
Couple of fine points. In a vacuum tube w/o a cathode the thingy that lights up is called the filament. If the tube has a cathode the thingy that lights up is called a heater.
Old skool sets that use filament or directly heated tube you will rarely find one side the filament grounded. What you will find is the filament winding will have a ct and at this point the ct acts as the cathode connection. Sometimes the ct is grounded but more often than not the ct is connected to a bias source.
On tube w/a cathode aka indirectly heated tubes, the reason for the one side being grounded is simple. It saves time and wire when construction.
GL
When my pals were reading comic books
I was down in the basement in my dad's
workshop. Perusing his Sam's Photofoacts
Vol 1-50 admiring the old set and trying to
figure out what all those squiggly meant.
Circa 1966
Now I think I've got it!
Terry
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