Mark, Also listed were oscillators, hi. Not sure if I would rely on a catalog especially Mouser for a definition. Sometimes one will find more than one item on a page, hi.
I do like Mouser. Good to see a company where small quantity can be found. I like Digi-Key little bit better. Interesting approach. 73, ron, n9ee/r >From: n9wys <[EMAIL PROTECTED]> >Date: 2007/10/24 Wed AM 11:15:25 CDT >To: [email protected] >Subject: RE: [Repeater-Builder] duplexer isolation and reciever noise budget > >OK - let me throw a little more gas on this fire... Just for giggles, I >went to Mouser Electronics, and selected their page for "Passive >Components". > >http://www.mouser.com/search/Refine.aspx?Ne=254016+1447464&N=1323038%2025427 >1&Ns=P_SField&RefType=Header > >Guess what?? Capacitors are listed there... as well as audio signal >transformers and EMI/RFI components. > >OK - flame suit on... "You may fire when ready, Gridley!" > >;-p > >Mark - N9WYS > >-----Original Message----- >From: [email protected] On Behalf Of Ron Wright > >Jeff, > >Beta is the current gain of a transistor, HFE and Hfe. No one would design >a transistor with a beta of less than one, but they do exist for transistors >can become defective. It is common for a new transistor to have a beta of >100, but after hours of use decrease to 20. A good design recognizes this >and adapts. They can also decrease to less than 1. Usually one replaces >them, but they are still acting as a transistor. An emitter follower will >have power gain only if the transistor has a beta, HFE or Hfe, greater than >1, but is active in any case. Having gain, voltage, current or power, does >not determine if a component is active. It is how the component reacts to >the energy. > >Yes diodes and transistor have junction capacitance, resistance, but get >their properties from entirely different means than passive devices such as >a resistor. Junction capacitance is a function of energy supplied to the >device. A capacitor does not change its properties based on energy >supplied, unless one exceeds its specs. A diode does. > >A transistor and diode change their properties based on the energy supplied. >This makes both active. > >As for the Quantum Mechnicancs this was over 40 years ago. One must know >high level calculus understanding the wave and heat flow equations to >follow. On one of my exams the instruction was to come up with the equation >for current flow in a diode. Only took about 3 pages. The 2nd question was >how much current was flowing with given parameters, holes, doping density, >and some others. If you got the first correct it was easy. If one goes >thru these derivations one can see a diode is a very active device. > >73, ron, n9ee/r > >>From: Jeff DePolo <[EMAIL PROTECTED]> >>Date: 2007/10/23 Tue PM 08:52:14 CDT >>To: [email protected] >>Subject: RE: RE: RE: RE: RE: RE: [Repeater-Builder] Re: duplexer isolation >and reciever n > >> >> >>> Sorry, but I totally disagree about a diode not being active. >>> If having to have gain then many devices such as a transistor >>> emitter follower with a beta of <1 would not be an active device. >> >>I assume you're using the term "beta" to really mean current gain of the >>stage. On my planet, an emitter-follower stage can't have a current gain >of >>< 1. Please draw me a schematic of an emitter-follower circuit that does. >> >>Or better yet, point me to a data sheet for a transistor that has a beta >>(hFE) spec of less than one. >> >>An emitter-follower is a current-gain stage. Assuming the voltage remains >>constant (or nearly so, minus the junction drop), but current increases, it >>provides POWER GAIN, which DOES make it an active stage. >> >>> Maybe if you had studied the equations with Quantum Mechanics >>> for a diode you might understand this. >> >>You don't need quantum mechanics to show that a diode is a passive device. >>But I'll indulge you; please explain how a diode (just a plain old silicon >>junction diode) qualifies as an active device using quantum mechanics. >> >>> A diode follows some >>> of the same equations as a transistor. >> >>So? A diode also "follows some of the same equations" as a capacitor, a >>resistor, an inductor, or even a fuse for that matter depending on how its >>used in a circuit. What's your point? >> >> --- Jeff > > Ron Wright, N9EE 727-376-6575 MICRO COMPUTER CONCEPTS Owner 146.64 repeater Tampa Bay, FL No tone, all are welcome.
