Yes, Dave, it is exactly what I experienced. Sent from my iPhone 4
David Gilbert <xda...@cis-broadband.com> 於 2013年3月23日 下午2:42 寫道： > > I guess I wasn't particularly clear, or maybe I just didn't say it often > enough. If you are competing against other hams, such as calling CQ in a > contest or calling DX from within a pileup, EVERY db counts no matter how > good the propagation is. An amplifier will often win the day for you even if > you can hear the other guy while he's running QRP. > > The same situation exists if it is noisy on the other end of the path, where > as little as two db will make the difference between clear copy and no copy. > Check the files on my website if you don't agree. The problem is ... the > noise level on the other end may be significantly different than the noise > level on your end. Just because you can hear him doesn't mean he can hear > you. > > More importantly, propagation doesn't open up to the same path loss each day > ... some days 5 watts gets the job done and some days even 1500 won't cut it. > And just because you can hear F5XXX running 5 watts doesn't mean that you > can hear PA3YYY unless he's running 1500 watts. > > My point is that EVERYTHING is situational and generalizations don't do > newcomers many favors. > > Dave AB7E > > > > > On 3/22/2013 8:34 PM, Ron D'Eau Claire wrote: >> Yes. An amp that takes you up 10:1 in power, e.g. 20 watts to 200 watts or >> 100 watts to 1,000 watts, makes a 10 dB difference in signal -- just a bit >> over one S-unit. >> >> I pointed out the beacon resource as a good example of how often that extra >> power is not needed on H.F., especially for narrow bandwidth modes. >> Otherwise we would not have QRP enthusiasts using simple verticals with DXCC >> awards. >> >> I liked the idea that new Hams can listen to the beacons themselves and >> decide whether the power difference is all that important. >> >> 73, Ron AC7AC >> >> >> -----Original Message----- >> That's a good resource but it doesn't tell the whole story. An amplifier >> will give you around 10 db improvement in signal on the other end. That's >> more than the difference between a dipole and a five element monobander. As >> little as 3 or 4 db will make a significant difference when competing >> against others in a pileup, and of course as little as 2 db can make the >> difference between no copy and clear copy if your signal is right at the >> noise level. >> >> http://www.ab7e.com/weak_signal/mdd.html >> >> Hams have turned their noses up at amplifiers for decades, but the reality >> is that an amplifier and a decent vertical is often a more cost effective >> way to put out a good signal than is low power to a tower and big antenna >> ... especially if you live in a low noise area where you don't need lots of >> discrimination to hear DX (and even then there are compact receive loops >> that make possible alternatives). >> >> Dave AB7En 3/22/2013 12:49 PM, Ron D'Eau Claire wrote: >>> For the newer hams, here's an interesting resource that will >>> demonstrate to you what a DX signal sounds like at 100 watts, 10 >>> watts, 1 watt and 0.1 watt. All you have to do it tune into the beacon >>> frequency of 14.100, 18.110, 21.150, 24.930, 28.200 using CW mode and >>> listen. The beacon stations in 18 countries take turns sending call >>> signs and 4 dashes, each dash in descending power level. You might be >>> amazed at how often you can hear 10 watts or less clearly from half >>> way >> around the world when the band is open. >>> When the band is not open, a kilowatt doesn't get through. >>> >>> A complete list of the stations, locations and the transmission >>> sequence is >>> at: >>> >>> http://www.ncdxf.org/beacon/beaconSchedule.html >>> >>> IIRC, all of the stations use a simple 1/4 wave vertical antenna. >>> >>> I'm not saying that an amplifier isn't useful, but this helps put the >>> advantage of having one in perspective. >>> >>> 73, Ron AC7AC >> ______________________________________________________________ >> 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 >> >> ______________________________________________________________ >> 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 > > ______________________________________________________________ > 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 ______________________________________________________________ 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
