Excellent point about seeing 3 times more stars with a gain of 1 magnitude (although 1 magnitude is 2.5 times brighter, so a little more than 3 dB). Also an excellent point about 1 dB yielding meaningful results in contest score even if no difference is discernible in an individual contact. I would add that if there is an opportunity to get small improvements in several areas, taking the attitude of looking at impact of a single improvement on a single contact can likewise lead to missing the big picture. Few of us can afford going for the last 0.5 dB in every part of a home station. I know I can't, but doing so is a lot more practical for a portable station. And getting the results of such a pursuit may be much more important for the portable station. Here is how I look at my portable capability. While it is part of the ham hobby, the portable HF radio is an essential piece of safety equipment for hiking expeditions. (OK, I could get a satellite device, but I don't like to pay the yearly fees.) When the need for an emergency call comes, I won't be in a good location, and the time of day won't match the conditions. My HF radio may not in fact be able to reach anyone at all, at least not immediately. But when I make decisions about portable gear, I want to be able to say that I did my best, meaning I went for all those individual 1 dB improvements that I could, within weight constraints. Together they will make a difference, and the 7 dB of going from 2 W in my KX1 to 10 W in a KX3 looks like a no-brainer. (I understand that the KX3 will be able to achieve 10 W using the built-in batteries.) A 30 W amp with built-in rechargeable batteries would certainly be interesting to look at too, but may not fit in my packing weight limits.
73, Erik K7TV >It is pretty widely accepted in contesting that an improvement in >*either* receive or transmit capability of 1 dB will yield a useful increase in the number of QSOs over a 48-hour contest, >even if it has an indiscernible effect on 99.5 percent of your contacts. > >73, Pete N4ZR > >The World Contest Station Database, updated daily at www.conteststations.com The Reverse Beacon Network at >http://reversebeacon.net, blog at reversebeacon.blogspot.com, spots at telnet.reversebeacon.net, port 7000 On 6/7/2011 8:23 AM, drewko wrote: > There is another way of looking at it-- how many additional contacts > would potentially be available by utilizing an increase of just 3db? > > I don't know the answer but there is a somewhat analogous situation in > astronomy having to do with the brightness of stars. They are also > measured on a logarithmic scale, called magnitude, each magnitude > representing twice or half the brightness level of the following or > preceding magnitude. A difference of one magnitude does not appear > very large to the eye, yet the ability to see one magnitude fainter > can yield three times as many stars. I imagine some similar effect > might pertain to radio waves. > > BTW, I'm not asking for more power in the KX3; would be quite content > with 10 watts, same as my K3. > > 73, > Drew > AF2Z > ______________________________________________________________ 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
