I agree that the KAT3(a) can run 100 watts for quite a while. I have run 100 watts in RTTY contests with both of my K3S(s) without issue. I have never used FT8, I am sure that my RTTY transmissions are shorter than a 13 second FT8 transmission however the non-transmit time in-between RTTY transmissions can be very short when CQing at times. I have no personal experience with the KAT3's power capability, I am sure that it depends on what it is matching. I have all OWA Yagis so I have no need for a tuner.
John KK9A David Gilbert AB7E wrote: I am reasonably certain that the KAT3 can handle 100 watts for a lengthy period to time (enough for normal FT8 purposes) if the SWR it is trying to match is low enough. But the original query didn't say how high an SWR he was trying to match. The KAT3 is certainly capable of matching some pretty high SWRs (well over 10:1), but the question is how long can it push 100 watts into an SWR that it could otherwise normally handle at lower SWR. Another factor is the phase of the impedance the KAT3 is trying to match. A high SWR could present either a capacitive load or an inductive load to the KAT3. In one case it could result in high currents within the KAT3 ... in another it could mean high internal voltages. So the real question is ... can the KAT3 survive for X amount of time when pushing 100 watts into a high SWR at most any phase? I can pretty much guarantee that nobody knows the answer to that question. I wouldn't be at all surprised if the KAT3 could handle 100 watts into a high SWR for periods of time that were comfortable for FT8 if the phase of the load impedance resulted in higher currents. I'm not so confident about that if the phase gave high voltages. Heating takes a bit of time to be destructive ... voltage breakdowns and arc overs happen very quickly. 73, Dave AB7E ______________________________________________________________ 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
