On Tue, 04 May 2010 01:03:43 -0500, flipper wrote:

On Mon, 3 May 2010 23:02:27 -0500, "Tim Williams"
wrote:

"flipper" wrote in message
. ..
So you really don't think it matters whether one tries to drive the
gate through a 10 ohm or 100 megohm resistor?

I said cutoff frequency, which means voltage source. Do you have a 0 ohm
source at ~1GHz? No? Then you won't get to see fT. ;-)

Tim

I know we won't see it so I have no idea what the heck your tap dance
is for.

Gm/Co was a popular figure of merit for tubes used in video amps and
oscilloscopes. They took a hockey-stick turn upward when frame-grid
tubes were invented, just before semiconductors took over.

Mosfets have impressive Gm/Co values, at the cost of high input
capacitance.

John