So why do I need an amplifier? I can just double my power by detuning my antenna tuner!
Vic K2VCO /4X6GP > On Jan 13, 2015, at 6:54 AM, Walter Underwood <wun...@wunderwood.org> wrote: > > All power ends in a load. > > Forward and reverse power measures standing waves, but all those waves go > into some kind of load. Nearly all of it, if you are lucky, goes to the > antenna. The rest goes to heat. Forward and reverse is just a way to measure > standing waves. It does not mean the some percentage of “reverse power” is > disappearing into your power amplifier. > > If you are running legal limit into forward power, you are quite likely > running illegal power into the the antenna. > > I was happy to get a C+ in my fields and waves class at Rice, but I do > understand this stuff. > > wunder > K6WRU > CM87wj > http://observer.wunderwood.org/ > >> On Jan 12, 2015, at 8:32 PM, Vic Rosenthal <k2vco....@gmail.com> wrote: >> >> I'm talking about forward minus reflected power. If you neglect losses, that >> is how much power gets to the antenna to be radiated. A wattmeter that >> measures forward power will be misleading if the SWR is high. My antenna has >> an SWR of about 2.5:1 on 40 m. When the transmitter delivers 100 watts to >> the line, there is about 120 watts forward and 20 watts reflected. I want a >> mode in which the wattmeter reads 100 watts in this situation. >> >> Maybe 'delivered' is a bad choice of word. I mean something like 'power >> delivered by the transmitter'. Obviously it would take magic to know how >> much power gets to the antenna after losses! >> >> Vic K2VCO /4X6GP >> >>> On Jan 13, 2015, at 12:08 AM, Phil Hystad <phys...@mac.com> wrote: >>> >>> Vic, >>> >>> What do you mean by "delivered power"? I presume you mean delivered to the >>> antenna (aka antenna system) but are you thinking power input to the W2 >>> minus all the losses. By all losses I mean all losses on transmission line >>> due to just plane old cable loss and higher losses due to higher SWR plus >>> any loss in tuner or other devices between W2 and the aether. >>> >>> Because, due to conservation of energy, that RF energy either goes out into >>> Electromagnetic waves (radiated) or it ends up as heat-loss somewhere in >>> the system. >>> >>> And, given all that, I don't think any RF/SWR power meter on the market can >>> measure "delivered power". >>> >>> Or, are you talking about something else. >>> >>> 73, phil, K7PEH >>> >>> >>>> On Jan 12, 2015, at 11:31 AM, Vic Rosenthal 4X6GP/K2VCO >>>> <k2vco....@gmail.com> wrote: >>>> >>>> I definitely want an LP100A, but I HAVE a W2, and while it is not as >>>> accurate, I still would like to see the delivered power! >>>> >>>>>> On 12 Jan 2015 21:12, Jim Brown wrote: >>>>>> On Mon,1/12/2015 7:56 AM, Vic Rosenthal 4X6GP/K2VCO wrote: >>>>>> I would like the W2 wattmeter to be able to display "delivered" power, >>>>>> that is, forward power minus reflected power. >>>>> >>>>> You want N8LP's excellent LP-100A. I had lusted after one for quite a >>>>> while, and bought W6OSP's unit after he died for about half price. The >>>>> LP-100A supports two couplers, which can be deployed on the outputs of >>>>> both transmitters in an SO2R setup, or on input and output of a power >>>>> amp. The LP-100A measures the complex Z at the coupler, so it can >>>>> measure the input Z of the amplifier under dynamic conditions. >>>>> >>>>> Now that I can measure power more accurately, I am able to run a dB or >>>>> more closer to legal limit when I want to for contesting. >>>>> >>>>> 73, Jim K9YC >>>> >>>> -- >>>> 73, >>>> Vic, 4X6GP/K2VCO >>>> Rehovot, Israel >>>> http://www.qsl.net/k2vco/ >>>> ______________________________________________________________ >>>> Elecraft mailing list >>>> Home: http://mailman.qth.net/mailman/listinfo/elecraft >>>> Help: http://mailman.qth.net/mmfaq.htm >>>> Post: mailto:Elecraft@mailman.qth.net >>>> >>>> This list hosted by: http://www.qsl.net >>>> Please help support this email list: http://www.qsl.net/donate.html >>>> Message delivered to phys...@mac.com >>> >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:Elecraft@mailman.qth.net >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to wun...@wunderwood.org > > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:Elecraft@mailman.qth.net > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to k2vco....@gmail.com ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
