Hello all,
I am the lucky owner of a K2/100. I finished the amplifier part just about 2 weeks ago and did not have an antenna available at the moment for a decent test. This weekend we had the PACC contest and decide to use the K2 (basically for 40m CW) during the group activity. I didn't have any problem! But I'm curious to hear some comments on a K2 during contest/dx-pedition activities. During the activity on 40m the heatsink became rather warm (I guess about 45 deg) and felt a specific hot-spot (must be close to the power transistors). I switched the fan to full operation to ensure maximum cooling. But during the activity on 15m (with a good SWR) I noticed that the heatsink temp became at least 5 deg more then during 40m activity (efficiency reasons?). This experience drove me to ask the next questions: 1) Is there a noticeable difference in heat-sink temperature when operating on higher bands? 2) Can this amplifier be tuned for 1 hour on a dummy with full output at any band without any semi-irreversible side effects? 3) I'm used to big tube amplifiers which need air-flow "throughput". The fan in the K2 is blowing into the box but there is no way out (kind of short circuit in terms of air flow). What is the reason for this cooling fan to blow into the box instead of making "forced" airflow through/along the heatsink. It looks to me that some extra holes into the cabinet might raise the efficiency of cooling dramatically (inside the box) The 2 most important reasons for electronics to stop functioning is over voltage/current and temperature stress by cooling - heating - cooling - heating etc. Even if the heating is within the specs, the overall product life is degenerating quickly by extremely temperature changes. It also stresses the solder point on the PCB. In general: Is the K2 designed to operate at full specs during contests/expeditions under any normal environmental condition (0 deg C to 40 deg C) without cooling down periods? Evert, PA2KW K2 : SN4836 _______________________________________________ Elecraft mailing list Post to: Elecraft@mailman.qth.net You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com
