My KPA1500 is S/N 00059. I don't operate full power all the time. I live in a compromised antenna area, and so I will use the amp as required to make contacts that are difficult assuming I can hear the station well enough to have the QSO.
I have not had problems with the weird display issue that has been reported, and also someone recently replaced their antenna tuner to solve a problem which I have not seen either yet. Thanks for this site, as it gives us a heads up if we would have similar issues with our equipment. Maybe I don't run the amp hard enough, my antenna will take 1500 watts, but I probably never push it that hard for long periods. I run FT8, but with 100 watts or less and I have made plenty of contacts. FT8 is whole another discussion. SSB is the least difficult for the amp to deal with. CW is harder and RTTY, FM,FT8 and AM are the worst. The fans on the power supply make some noise, but I have had several tube amps over the last 40 years that are louder. I haven't installed the latest software update issued in July, so I need to see if that makes any difference. I was involved with the design specification, and purchase of medium and high voltage transformers for my career. Cooling of electrical equipment is a little more complex than just installing fans. There are proper air flow requirements to look at in the design, so the air doesn't get short circuited, and actually hurt the process. So more air isn't always better if it is not properly applied. Transformers have RTD's or Thermocouples imbedded in the windings to measure transformer temperature, because that is the "hottest spot" of any transformer. The hot spot temperature is made up of the ambient air temperature normally 40 C maximum is used with a 30C average over a 24 hour period, and the temperature rise of the unit under load. Most electrical equipment design is based on a 40C maximum ambient but I didn't see in the manual what Elecraft considered for a maximum. Regardless, the ambient heat around the amplifier must be controlled and not trapped around the unit. An air conditioned space or proper ventilating for area is critical. If you don't remove the heat your unit will work harder and could make more noise than other units. Wayne or Eric can comment, but RF amplifiers must follow similar laws of physics. The heat sink temperature must be maintained or the devices primarily the LDMOS final amp units will fail. There are average and maximums I would assume are used in the Elecraft design. Ambient air must be kept at a certain maximum and air flows must not be restricted. At this time, it good to provide feedback to the vendor on operational concerns of the equipment, and I did plenty of that over the years. However, I usually realized there were some people, who did this for a living, and I was a consumer maybe a smart consumer, but still I didn't design transformers as my main employment. With all the KPA1500's still under warranty I don't think it is a good idea to modify or change anything with regards to the operation, and design of the KPA1500. Again, I am not Wayne or Eric, but I think you are doing it at your risk. I will wait for Wayne and Eric to come out with improvements, and updates based on customer and other inputs, but I will not modify the KPA1500 in anyway including external programs that change the operation without the supplier approval. I guess after the warranty period anyone can do what they want, but don't expect the supplier to honor any warranty issues that may have been created due to prior modifications of operation. Just as with a transformer, cooling of an RF amplifier is critical to the proper operation and long term reliability and life of the unit. Heat is the main cause of failure of any electrical equipment! Bill, K8ZCT -- Sent from: http://elecraft.365791.n2.nabble.com/ ______________________________________________________________ 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
