6AS7G Grid Voltage ??

[Zero Cool]

If i have a 6AS7G with 150V plate voltage, how do i determine how many -V are required at the grid to fully turn it off?

 

[GordonW]

You just need to look at the plate curves. Here's a datasheet, with the plate curves, for the 6AS7GA (which is equivalent to what you have):

http://tubes.mkdw.net/sheets/093/6/6AS7GA.pdf

Looking at that curve... you just go across the bottom of the graph, to the plate voltage you want, and see which one of the grid bias curves is closest... this will give you the grid voltage.

For 150V B+, looks like it needs between 100 and 110v negative, to completely drive it down to cutoff...

Regards,
Gordon.

 

[Zero Cool]

Thank you! I just wanted a double check to see if what i thought i was learning and figuring out was in fact correct!


Thanks!