Stabilizing drift? I need some help...

[Dragonfly]

Threads like this are the reason I keep coming back !LOTS of great info here...

Thank you !

AC

[johngreene]

I noticed that as well...and 90% of the literature also has 4 volts on grid 2...If I end up going the power supply route, I may end up playing with that as well since it increases the gain considerably.  I was just trying to maximize battery life, but batteries just might not be an option. 

That's because at 4 volts, grid 2 is out of the picture. So any Grid 1 parameters are made with Grid 2 fully 'on'.

--john

[zachomega]

That actually makes perfect sense.  I don't know why I couldn't see that before.  Now Sir H.C. self cascoding thing makes sense too.   

You guys have been amazingly helpful! 

-Zach Omega

I noticed that as well...and 90% of the literature also has 4 volts on grid 2...If I end up going the power supply route, I may end up playing with that as well since it increases the gain considerably.  I was just trying to maximize battery life, but batteries just might not be an option. 

That's because at 4 volts, grid 2 is out of the picture. So any Grid 1 parameters are made with Grid 2 fully 'on'.

--john

[Sir H C]

I used to work with this PhD who was a device physicist (designed transistors for ICs).  His pride and joy was a dual gate FET he made for a process no one cared about.  It was sad but funny.

[dschwartz]

Hi zachomega:

i have some dual gate mosfets lying around, but i dont know what to do with them...do you have the schematic of the device youre making, or at least a concept schematic?, i´ve found some RF schematics, but all those antennas and coils get me very confused...

i hope you have and share any schematic using this device as a simple amplifier...thanks!!!!

[zachomega]

Well without seeing the data sheets for your transistors, I can't say for certain what will and won't work.  In my case, simply a 1k drain resistor, 1 meg gate resistor, and having the gate 2 and source tied together and grounded through a 100 ohm resistor seemed to work.  Still have to try it (the original pedal) again on a power supply and check for the voltages going all over the place. 

-Zach Omega

Hi zachomega:

i have some dual gate mosfets lying around, but i dont know what to do with them...do you have the schematic of the device youre making, or at least a concept schematic?, i´ve found some RF schematics, but all those antennas and coils get me very confused...

i hope you have and share any schematic using this device as a simple amplifier...thanks!!!!