Ron, I agree 100% Ron. I am elmering new hams and use the beacons as a good tool to explain the difference in signal strength with increase of power and relation to db's. Cant think of a better way to demonstrate. It gives credence to our explaining that they need to focus on the antenna system first, not an amp.
Bob K6UJ On Mar 22, 2013, at 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:[email protected] > > 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:[email protected] > > 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:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
