The fail temperature of the PA's is going to be well known and documented. Then a safety factor is added. But I seem to recall that early comments on heat design criteria was for 10m key down, 100% duty cycle, without damage. But that is just the memory talking. YMMV
73 Dave Wilburn NM4M rfenab...@gmail.com wrote: > I am now wondering how do you settle on "Normal", "Heavy" and simply "Flat > out" to come up with a "design limitation?" From the factory? > > Much conjecture and pure guesswork has been written in recent posts as well > as some very informative opinions on the cooling system used by Elecraft. > > Perhaps we should hear from Elecraft on what design criteria was used when > the decision was made to use the existing cooling arrangement. > > Does the addition of the KPA-3 and now the 2m option board alter the > effectiveness of the cooling system as designed? > > Just how *heavy* is heavy?..use or perhaps abuse..? > > Feeling around a radio as soon as you power down appears to me to be the same > as sticking your fingers on a radiator of a car immediately after switching > off. These days a lot of cars run electric fans to allow an even cool down > period after running. > > To make my point clearer, when I use the ride-on mower for an hour or more, I > run the motor for a few minutes after I finish to effect a cooling down of > the motor, I do not run my K3 (or any other radio) for RTTY then pull the > power, call me cautious perhaps, but it just seems logical to me. > > I hope Wayne, Eric and Lyle et al post a response in depth on this topic as > many of us have differing points of view. > > My two cents worth, or was that a Nickel? > > Gary > VK4WT > K3 s/n 679 > Sent via BlackBerry® from Telstra > ______________________________________________________________ > 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
