Would not this imply a maximum efficiency of 50% ? P-T
On 1 August 2014 00:40, Matt VK2RQ <[email protected]> wrote: > I think we have hit the posting limit for this topic, so I'll just finish > with this remark: the maximum power transfer between a power amplifier and > its load will occur when the source and load impedances are complex > conjugates (this can be seen using the voltage divider equation and some > differential calculus). In the case of a purely resistive load, this > reduces down to the source and load resistances being equal. > > 73, > Matt VK2RQ > > > On 1 Aug 2014, at 8:24 am, Per-Tore Aasestrand <[email protected]> wrote: > > > > Hi list, > > > > Isn't an RF transmitter or PA actually more like a current generator? Its > > internal resistance is kept low in order to reduce internally dissipated > > power, with consequent reduction in efficiency. It is usually designed to > > work efficiently into 50 ohms. > > > > It is important to know the difference between these two statements: > > (A) The transmitter has a 50 ohm output impedance. > > (B) The transmitter is designed to work into a 50 ohm load > > > > A transmitter will be able to put its rated power into a 50 ohm load, but > > this says nothing about its output impedance. That is why I don't think > > conjugate matching will be appropriate. > > > > (Hope this is not getting too much OT now) > > > > Per-Tore / LA7NO > > ______________________________________________________________ > > Elecraft mailing list > > Home: http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/mmfaq.htm > > Post: mailto:[email protected] > > > > This list hosted by: http://www.qsl.net > > Please help support this email list: http://www.qsl.net/donate.html > > Message delivered to [email protected] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]
