Hi Randy, Does your K3 #3260 have the newer MOSFET PA? I believe the K3 switched the PA from bipolar to the newer MOSFET design at some point (mine is #82!). I agree with you that the 20/30m LPF ought to be a prime suspect. Everything else is common and 14MHz should be very close to the center of the total frequency range of the transmitter. My K3S has not had any reliability problems either, but it sees fairly light duty with SSB only and no heavy duty "run mode" contest use.
BTW, I checked the current draw on 30m (on the K3S) which *shares the same LP filter*. It is an average 17.5A. But 30m is lower in frequency and thus farther away from the filter cutoff. 40m, 15m and 10m LP filters are also shared with a lower frequency band, but do not cause an elevated current draw. Knut - AB2TC Randy Farmer-2 wrote > Interesting. My K3S (10175) and K3 (3260) exhibit the exact same > behavior. My K3S had a problem with low power stability on 80 meters > that resulted in field replacement of the 100W PA module, but the 20 > meter current draw didn't change. My working hypothesis is tolerance > stack-up in the 20 meter LPF, but that's just a supposition. Both radios > have been used for fairly serious contest duty, the K3 since 2009 and > the K3S since 2016, with no reliability problems. > > 73... > Randy, W8FN > > On 9/5/2020 10:20 PM, ab2tc wrote: > <snip> -- 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
