Thanks to Harry and John for the excellent advice on the replacement fan. The UTEC fans that came with my most recent KPA3 (September 2013) were very annoying to me since I have a quiet radio room with no amplifier. The problem was not so much one of volume as sound quality. The fan noise was buzzy, for lack of a better description, probably from a combination of undamped mounting and poor bearing design.
For those who want to replace their fans with the Noctua NF-A6x25 I have a method to make the installation neater. Obtain two Molex two-terminal 0.1" connectors (WMLX-101 from Fry's Electronics or equivalent) before your new fans arrive. Follow Harry's instructions to use the Noctua silicon rubber anti-vibration mounts to attach the fans to the Elecraft fan panel and to attach the Elecraft fan screens with the Noctua-supplied screws. Some care is required when pulling the mounts through the fan mounting holes so you don't bend the aluminum fan panel at the thin points. Measure the two different lead lengths on the old fans and cut the respective new fan leads to the same lengths plus a little extra to crimp the new Molex connectors on. Cut the black sleeve back to expose enough wire length to crimp on the Molex terminals and attach the housing. Strip the red and black wires on each lead and crimp and solder on the new connector terminals. Remember the red fan leads go to the left when viewed from the rear of the K3. Planning the orientation of the wires is important for the neatest end result. Fold the yellow wire back into the sleeve and snap the terminals into the connector block in the correct orientation on each lead (so that the red wire is on the left when installed). Plug the two connector blocks onto the KPA3 fan pins and attach the fan panel per the original KPA3 instructions. You will now have minimal interference from the fan leads in the space between the panel and KPA3 heat sink. Using this technique is most important when you have coaxial cables from other accessories occupying the same area, as I do. Enjoy the quiet fans - I am! 73 Gary, N7IR John Farmer <zen...@netspace.net.au> wrote: > I'll do the same. Trimming the contact plug down will be > simpler than cutting it off and wiring on a 2 pin. Harry Yingst [ <mailto:hlyin...@yahoo.com>] wrote: > I use the Hardware that came with the fans. > I trimmed the 3 contact plug down to 2 and removed the 3rd (unneeded) wire > I attached the grills with screws (supplied with the fan) ______________________________________________________________ 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
