According to Wikipedia a transistor is not active. Here they state active devices as suppling power and passive as not.
"""In control systems and circuit network theory, a passive component or circuit is one that consumes energy, but does not produce energy. Under this methodology, voltage and current sources are considered active, while transistors, resistors, tunnel diodes, glow tubes, capacitors, and other dissipative and energy-neutral components are considered passive.""" Then later they say: """ Here, devices like diodes would be considered active, and only very simple devices like capacitors, inductors, and resistors are considered passive. In some cases, the term "linear element" may be a more appropriate term than "passive device." In other cases, "solid state device" may be a more appropriate term than "active device."""" The search was under "active component" They do a good job in their explanations. They take different situations and uses of components and state as being active or passive. Every engineer I've worked with, and I've worked with a bunch from BS to PHDs, consider a diode as an active device. 73, ron, n9ee/r >From: [EMAIL PROTECTED] >Date: 2007/10/24 Wed PM 10:45:20 CDT >To: Repeater-Builder@yahoogroups.com >Subject: Re: RE: RE: RE: RE: RE: RE: [Repeater-Builder] Re: duplexer >isolation and reciev > >At 10/24/2007 19:26, you wrote: > >>I would consider anything that uses a semi-condutor material to be >>active, Silicon and Germanium transistors included. > >According to Wikipedia, a passive device is a device that is not capable of >power gain. If it is capable of power gain, it is an active device. > >If needed, I can probably dig up some definition in an IEEE reference that >essentially says the same thing. > >Bob NO6B > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.