View Single Post
  #1   Report Post  
Old August 9th 04, 09:35 PM
SBC
 
Posts: n/a
Default Ft for RF transistor

Thanks for all your help.

- Bruce Raymond/ND8I


"bviel" wrote in message
...
Searched my datasheets, HF-Low, (27Mhz), working frequentie.
Working frequentie is most the time 1/10 of the Ft, Ft is 270Mhz ?
Ft increases with higher Ic, draw more current en cool the transistor,
should make it working at higher frequenties !
Greetings Bas.
Whished a had the book you mentioned !
Not available in Europe, available by ARRL America, delivering time
half a year.


"SBC" schreef in bericht
. ..
Well, I picked up a couple of Mitsubishi 2SC2166s to play with.
I'm interested in using the transistor for HF or low VHF. I'm
only playing, so nothing I do is critical. I just want to see what
I can make the transistors do.

I'd like to design a circuit, model it, and then mock it up and see
how close I come with my model. The gotcha is that the datasheet
shows just about everything I think I need except for the gain-
bandwidth product (Ft). I'm doing my modeling based upon Wes
Hayward's Introduction to RF Design (absolutely wonderful book)
and EMRFD (not bad, either).

My first question - is this just a fool's errand? In other words,
is this transistor just typecast for CB finals and for some reason
it's not possible to use it for anything else?

My second question - assuming the answer to question #1 is
no, is there a reasonable way to estimate Ft from the other
data (such as Zin and Zout)? I'm generally suspicious of any
derived values, but in this case derived data would be better
than nothing. I'm assuming the Ft is probably somewhere
between 100-200 MHz, but that's just a guess.

Thanks for you help,
Bruce Raymond/ND8I