08-09-2014, 10:24 AM
Either way can work.
The DC potential of the 1st grid should be that pf the Cathode, so it can be coil to GND via cap and the grid biased by the resistor to Cathode, or coil via resistor to Cathode.
http://www.radiomuseum.org/tubes/tube_6a7.html
The DC potential of the 1st grid should be that pf the Cathode, so it can be coil to GND via cap and the grid biased by the resistor to Cathode, or coil via resistor to Cathode.
http://www.radiomuseum.org/tubes/tube_6a7.html