[Amps] RF power transistor curve trace question

Steve Thompson g8gsq at fs2.com
Wed Jun 17 04:21:59 PDT 2009


> 2. I do not know about transistor ballasting. Is there a standard way to 
> measure it? Are there standard values? What value would be sufficient to 
> operate in class AB?
> 

A method I used when on the manufacturing side was to put a 
defined current (typically a few 100s mA) through the b-e junction 
then measure the c-e voltage with a DVM. To all intents and 
purposes the voltage you measure is that across the emitter 
resistor so, knowing the current, you can calculate Re. Expect 
values in the low tenths of ohms.

Steve


More information about the Amps mailing list