The first reference is audio only, no RF component, Ref 2 is questionable as the SSB analyzer lacks the low frequency dynamic range, at 1 Hz and below it should be more like 40dB/Hz , a 100 MHz crystal oscillator as a test would have ben better . But he is much more hones using AF=2, maybe slightly off, but not 1 as some use. About CEL :
FOR SSB noise not useful but at least it shows that AF and KF , both, are bias dependent, must forget this . SILVACO page 112 again is low frequency modeling, not applicable for RF, one need to know the AM/PM conversion. This is a real tough subject and most approaches are incorrectly, use curve fitting or test equipment with not enough dynamic range ... 73 de Ulrich , N1UL In a message dated 7/19/2015 10:36:10 A.M. Eastern Daylight Time, [email protected] writes: For a method to extract AF and KF try this: <http://joerg-berkner.de/Fachartikel/pdf/2000_AKB_Berkner_1f_noise.pdf> see also <http://scholarcommons.usf.edu/cgi/viewcontent.cgi?article=2270&context=etd> from page 55, on the parameter extraction for the BJTs usually AF is greater than 1, as you can see in this appnote from CEL: <http://www.cel.com/pdf/appnotes/an1026.pdf> A SILVACO appnote on how to model for SPICE2 for 1/f (from page 45): <http://www.silvaco.com/content/kbase/noise_modeling.pdf> On Sun, Jul 19, 2015 at 4:59 AM, John Miles <[email protected]> wrote: > >> -----Original Message----- >> From: time-nuts [mailto:[email protected]] On Behalf Of KA2WEU-- >> - via time-nuts >> Sent: Saturday, July 18, 2015 3:40 PM >> To: [email protected] >> Cc: [email protected]; [email protected] >> Subject: Re: [time-nuts] how to find low noise transistors >> >> BFG540 >> >> > > That's what I mean -- both BFG540 and BFG591 have been discontinued by NXP. Guess they don't sell enough of them these days. > > -- john, KE5FX > Miles Design LLC > > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there. _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
