On Thu, 22 Jul 2004 10:32:55 GMT, Robert Baer
wrote:

At RF, the base spreading resistance can be large when compared with
the calculated emitter resistance; this makes a serious contribution to
input noise and the NF of the stage.

Sorry guys, I did *mean* to include BSR in series with the B/E
junction resistance, so any reference I made to this junction
resistance should be taken to mean the total of the two together.

So the particular version of the model one uses can be rather poor in
determining real-life NF.

NF isn't a consideration in this instance; please ignore it.
And I am well aware of the pi-model. I just want to know if I have it
right that Ebers-Moll will work accurately into UHF provided one
allows for the feedback capacitance and emitter junction capacitance
shunting the input signal around BSR+EBR and thereby reducing the
signal voltage developed across them. Do I have this right?

Thanks,

Paul
--

"What is now proved was once only imagin'd." - William Blake, 1793.