The RFsensing on the K3 is a real trick. The frst 'dit' may suffer a mild truncation on band change, but this only happens if you don't press a band button prior to transmitting.
Low power band changing does occur with 1W on CW. Tested it just now with a band change from 10M to 15M Maybe this is of help? Gary On 12 May 2011 08:41, Gary Gregory <[email protected]> wrote: > Joe, > > Just to clarify, the last measurements were on 28.447.44 (a clear frequency > here at the moment), SWR is 1.1:1, tri-band yagi. > > > On 12 May 2011 08:40, Gary Gregory <[email protected]> wrote: > >> Joe, >> >> 325W @ 15W drive >> 410W @ 20W drive >> 490W @ 25W drive >> 510W @ 26W drive >> 530W @ 27W drive >> 560W @ 28W drive >> 580W @ 29W drive >> 600W @ 30W drive >> 630W @ 31W drive >> 650W @ 32W drive >> 675W @ 35W drive >> 690W @ 37W drive >> 700W @ 40W drive >> >> Is this still about right for your calculations..... >> >> Gary >> >> >> On 12 May 2011 08:18, Joe Subich, W4TV <[email protected]> wrote: >> >>> >>> Adding gain calculation ... >>> >>> >>> > 2W = 30W 11.8 dB >>> > 2.5W = 40W 12.0 dB >>> > 3w = 50w 12.2 dB >>> > 3.5w = 60w 12.3 dB >>> > 4w = 70w 12.4 dB >>> > 4.5w = 75w 12.2 dB >>> > 5w = 80w 12.0 dB >>> > 5.5w = 90w 12.1 dB >>> > 6w = 100w 12.2 dB >>> > 6.5w = 110w 12.3 dB >>> > 7w = 120w 12.3 dB >>> > 7.5w = 130w 12.4 dB >>> > 8w = 150w 12.7 dB >>> > 8.5w = 160w 12.7 dB >>> > 9w = 170w 12.8 dB >>> > 9.5w = 180w 12.8 dB >>> > 10w = 190w 12.8 dB >>> > 11w = 200w 12.6 dB >>> > 12w = 225w 12.7 dB >>> >>> The numbers look about right including the decreased gain at low level >>> (as expected). Using 12.6/12.7 dB would indicate 33W drive for 600W >>> out. 40W drive for 600W output would indicate ~1 dB of compression. >>> >>> 73, >>> >>> ... Joe, W4TV >>> >>> On 5/11/2011 5:28 PM, Gary Gregory wrote: >>> > Stan, >>> > >>> > Allow some variation to antenna variations also. >>> > >>> > This on 15M, swr is 1.0:1 >>> > >>> > 2W = 30W out >>> > 2.5W = 40W >>> > 3w = 50w >>> > 3.5w = 60w >>> > 4w = 70w >>> > 4.5w = 75w out >>> > 5w = 80w >>> > 5.5w = 90w >>> > 6w = 100w >>> > 6.5w = 110w >>> > 7w = 120w >>> > 7.5w = 130w >>> > 8w = 150w >>> > 8.5w = 160w >>> > 9w = 170w >>> > 9.5w = 180w >>> > 10w = 190w >>> > 11w = 200w >>> > 12w = 225w >>> > >>> > NOTE to ALL: This was not done with lab equipment or even a dummy load. >>> This >>> > was measured using a K3 and a tri-band yagi and a cw tone. >>> > >>> > Gary >>> > >>> > On 12 May 2011 07:13, Al Lorona<[email protected]> wrote: >>> > >>> >> It's very easy to measure the 1-tone gain compression characteristics >>> of an >>> >> amplifier. The desired result is a graph of Pout vs. Pin, with Pin on >>> the >>> >> horizontal axis and Pout on the vertical. >>> >> >>> >> So what one needs to do is set Pin to the amp, and measure Pout into a >>> >> dummy >>> >> load. If you do this for several values of Pin, you'll be able to plot >>> all >>> >> of >>> >> those measured points on the graph. It will look like a pretty >>> straight >>> >> line >>> >> toward the lower Pin values, then it will flatten out (become more >>> >> horizontal) >>> >> as Pin (and Pout) get higher. >>> >> >>> >> The slope of the line is the gain of the amplifier. >>> >> >>> >> Very often the Pin values are 1 dB apart. One dB is about a 25% >>> increase in >>> >> power. Meaning that if you are measuring Pin in Watts, then you can >>> set Pin >>> >> to >>> >> roughly the following values: >>> >> >>> >> 1, 1.5, 2, 3, 4, 5, 7, 10, 13 Watts, etc., >>> >> >>> >> and measure the Pout at each value. The values should be converted to >>> dBm >>> >> before >>> >> plotting. That's all there is to it. >>> >> >>> >> This is all done in CW mode. If you want to go further, you can go >>> into SSB >>> >> mode >>> >> and apply two tones to the amp (which a K3 has the ability to do) and >>> then >>> >> look >>> >> at the output of both the K3 and the KPA500 with a spectrum >>> analyzer... but >>> >> I'll >>> >> leave that explanation for another day... or it can be found on the >>> web. >>> >> >>> >> Al W6LX >>> >> ______________________________________________________________ >>> >> 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 >>> >> >> >> >> -- >> >> VK4FD - Motorhome Mobile >> Elecraft Equipment >> K3 #679, KPA-500 #018 >> Living the dream!!! >> >> > > > -- > > VK4FD - Motorhome Mobile > Elecraft Equipment > K3 #679, KPA-500 #018 > Living the dream!!! > > -- VK4FD - Motorhome Mobile Elecraft Equipment K3 #679, KPA-500 #018 Living the dream!!! ______________________________________________________________ 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
