Many of us would feel a psychological edge if we pushed an amplifier such as the KPA500 from its rated 500 W to, say, 625 W. It sounds like so much more, doesn't it? It sure makes us feel better to think that we're louder on the other end.
But first, on your S-meter take a look at the width of one S-unit, which is commonly held to be 6 dB. Now imagine that single S-unit divided into six equal parts, each of them 1 dB. If you have an analog S-meter the needle is probably wider than one of these parts. Do you think you could hear a difference if a signal increased (or decreased) by one of these skinny little 1 dB increments? Well, the increase from 500 to 625 Watts is a little bit *less* than one of these increments. Furthermore, especially if you're on phone, the increase in in-band intermod that results from pushing any amp may actually subtract a little bit of intelligibility from your SSB signal. I don't know what the dB equivalent of this "intelligibility loss" would be... but what if it's like 0.5 dB? It's simply not worth it. If you ever want to calculate for yourself the dB change from an increase or decrease in power one place you can find the equations (as well as a link to an on-line calculator) is here: http://www.radio-electronics.com/info/formulae/decibels/decibel-formulae-equation.php . Someone will say, "But when your signal's right under the noise floor on 160 CW, that extra 0.9691 dB might help." I agree in advance-- to save you the trouble of having to point out that rare situation. For the rest of us, the conservatively rated output of the KPA500 should be just fine. Al W6LX ______________________________________________________________ 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
