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 arch...@mail-archive.com
