Don: I guess you never noticed my response to Ken that I posted last Friday. The fan moves air INTO the K2, across the PA and it comes out around the heat sink fins near the front of the K2, just as George said.
I suggested Ken contact you after he determined that he had in fact set the bias current correctly and the fan was operating correctly because you work on K2s quite often. It's been five years since mine was apart! 73, Ron AC7AC -----Original Message----- From: Elecraft [mailto:[email protected]] On Behalf Of Don Wilhelm Sent: Sunday, May 21, 2017 6:19 PM To: George Winship, NC5G; [email protected] Subject: Re: [Elecraft] K2/100 overheating? George, I will check the fan air flow direction tomorrow because I am uncertain. If you have the label out and the wires on the correct holes, yours is likely OK. There are 2 philosophies about the fan direction. One is that you should exhaust the heat and let the assembly draw cool air across the hot components. The other says to let the fan "blow" on the hot components. The major difference between the two is that a blower fan adds heat to the air (due to the work produced by the fan), but adds the benefit of directing the air flow to the area to be cooled. An exhaust fan does not add its work product heat to the air being moved, but the cool air cannot be directed as well because it is spread over a large area in the enclosure box. 73, Don W3FPR On 5/21/2017 11:26 AM, George Winship, NC5G wrote: > Interesting. I built my K2/100 about 17 years ago and the fan has always > drawn air into the cabinet and exhausted over the heatsink. So, I rechecked > the manual and disassembled my rig to check for proper assembly. Fan label > is facing out and wires are soldered to the right pads(red=+, black=-). Was > there maybe a change in later models? > > 73, George > > > > Make certain the fan is mounted with the label out and that the red wire > is in the +hole and the black one in the -hole. > The fan should exhaust the hot air. Cooler air flows in at the front of > the heatsink. > > > > > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/K2-100-overheating-tp7630828p7630883.ht ml > Sent from the Elecraft mailing list archive at Nabble.com. > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[email protected] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [email protected] > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [email protected]

