Hello Group, I would like to learn more about the design and priniciples of solid state RF linear amplifier. The PSU inside KPA500 is linear and non-regulated. In my case, under no load condition, the HV is about 73v but is about 53v under full load. The HV is changing according to the power output. Then, how can the linearity of the amplifier be maintained? I studied (or used in the past) some of the linear amplifiers in the market. Some of them are having regulated HV and some of them not. What is the design criteria of choosing regulated or non-regulated HV? Some of the reflector members are so kind to provide me with test reports of KPA500. I tried to compare KPA500 with the ARRL reports of other linear amplfiers. Surprisingly, the IMD of SPE 1ka-Expert is the best among the solid state amplifers and better than KPA500. However, SPE only uses 6 x MRF150 to produce some 900w output. Apparently, the MRF150 are quite pushed to the extreme. How can SPE achieve such a low IMD in accordance with ARRL report? SPE also uses linear and non-regulated PSU. One the other hand, ICOM ICPW1 (one of my favorite work horse) is using 8 x MRF150 and regulated switching PSU. Its IMD is worse than SPE. Within my limited radio knowledge, I cannot find the answers for the above. Can anybody here please enlighten me or direct me to suitable webpages for my own self-study? Thank you in advance as always.
TNX & 73, Johnny VR2XMC ______________________________________________________________ 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
