Hi Yes, you can also look at it as “damping” or" de-Q-ing”. You trade off a bit of isolation for stability. Put another way, the resistor will take the isolation of the stage down a bit.
Another practical point on the stage - you want the base bypass as close to the end of that resistor as you can get it. You want the resistor right up against the base. Inductance in the base lead is a really bad thing in this case. Bob > On Jul 2, 2016, at 1:00 PM, Attila Kinali <att...@kinali.ch> wrote: > > On Fri, 1 Jul 2016 12:28:44 -0400 > Bob Camp <kb...@n1k.org> wrote: > >> Real cascode circuits can be built with RF transistors. They also can be >> simulated. >> Simulating them with the “standard” models is a PIA. The issue is that the >> inductance >> of the package is not de-embedded from the test “socket” as carefully as it >> might be. >> There is also the somewhat non-intuitive need to stick a low value resistor >> in the base. >> Done properly, they are very reproducible and reasonably insensitive to >> load. > > Thanks! That resistor in the base did the trick! > Am I right in the assumption that the resistor gives the transistor > some negative feedback and thus prevents it from oscillating? > > > Attila Kinali > > -- > Malek's Law: > Any simple idea will be worded in the most complicated way. > _______________________________________________ > time-nuts mailing list -- time-nuts@febo.com > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
