[Elecraft] K2 output power on 10 meters
Hi all, I have been tweaking on my K2 for the last several days trying to get the transmit power up to snuff on 10 meters. Right now, the best I can squeeze out is about 8.5 Watts. I'm in pretty good shape on 12 meters, about 10 Watts there, with max output of 14 Watts on 40m. I have rewound and elevated T2, adjusted the turns spacing on the low pass filter toroids L21 and L22, and re-peaked the bandpass filters. 8.5 Watts is as good as I can get. Is this typical for a K2? Is there something else I need to be looking at? Thanks in advance for any suggestions. 73, Mike, K4GU __ 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
Re: [Elecraft] K2 output power on 10 meters
U are more or less there. 73 Johnny vr2xmc Sent from my iPhone 4 Mike and Alicia Fanning 於 2010年12月31日 下午12:36 寫道： > Hi all, > I have been tweaking on my K2 for the last several days trying to get > the transmit power up to snuff on 10 meters. Right now, the best I > can squeeze out is about 8.5 Watts. I'm in pretty good shape on 12 > meters, about 10 Watts there, with max output of 14 Watts on 40m. I > have rewound and elevated T2, adjusted the turns spacing on the low > pass filter toroids L21 and L22, and re-peaked the bandpass filters. > 8.5 Watts is as good as I can get. Is this typical for a K2? Is > there something else I need to be looking at? > > Thanks in advance for any suggestions. > > 73, > Mike, K4GU > __ > 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
Re: [Elecraft] K2 output power on 10 meters
Mike, The K2 maximum output power on 10 meters varies due to component tolerances and care taken during construction. Since you have apparently done the normal things to improve it, and the power is still low, it may be time to consider component tolerances - primarily for the Q5 and Q6 stages. One easy way to bring up the 10 meter output power is to change Q6 to a transistor that typically has better high frequency performance. The 2SC2166 that is being shipped with new K2 kits seems to produce better output on 10 meters than some older K2s that I have worked on - I guess this is tolerance drift over time, but that is only a guess. Another way to increase the 10 meter output power is to change Q6 to a 2SC5739 which has better high frequency performance specification than the 2SC2166. If you do make this change, also change the value of R46 from 270 ohms to 330 ohms to keep the Q6 transistor at a cooler temperature. 73, Don W3FPR On 12/30/2010 11:36 PM, Mike and Alicia Fanning wrote: > Hi all, > I have been tweaking on my K2 for the last several days trying to get > the transmit power up to snuff on 10 meters. Right now, the best I > can squeeze out is about 8.5 Watts. I'm in pretty good shape on 12 > meters, about 10 Watts there, with max output of 14 Watts on 40m. I > have rewound and elevated T2, adjusted the turns spacing on the low > pass filter toroids L21 and L22, and re-peaked the bandpass filters. > 8.5 Watts is as good as I can get. Is this typical for a K2? Is > there something else I need to be looking at? > > Thanks in advance for any suggestions. > > 73, > Mike, K4GU > __ 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
