[Elecraft] KPA1500 Power Supply Fan Noise

[turnbull]

Eric, I do not understand your problem with the PS and audible noise.    The larger fans in my KPA1500 are quiet.   Any noise is at low freq.    The RF deck does produce noise and I wish it did not.    My Sony noise cancelling phones handle this noise well.   Maybe your PS has faulty fans.   Are the bearings okay?    Please do not get annoyed with me but this is my experience.I suppose cooling junction temperatures low takes a lot of air.    My Acom 2000A tube amp is much quieter.73 Doug EI2CNSent from my Samsung Galaxy smartphone.
-------- Original message --------From: eric norris via Elecraft <elecraft at mailman.qth.net> Date: 11/06/2019  00:57  (GMT+00:00) To: lists at w2irt.net, lists at w2irt.net, Elecraft Reflector <elecraft at mailman.qth.net> Subject: [Elecraft] KPA1500 Power Supply Fan Noise More broadly, has there been any progress on reducing the piercing power supply fan noise on the KPA1500 when only using it as a tuner or an antenna switch?  I complained about this a year ago, and I find it completely unacceptable.  No set of noise-reducing headphones that I have tried works well enough to make the noise tolerable.  I've tried moving the PS deck around with minimal improvement.  This just doesn't seem to fit Elecraft's philosophy of a quiet operating environment.  Why do these fans have to operate at full throttle when there is minimal current draw from the rf deck?  Why do these fans create such a piercing high-pitched note?  If there is no response from Elecraft, what have other ops done--short of moving the PS into an adjoining room--to mitigate the scream?Thanks,73 Eric WD6DBMSent from Yahoo Mail on Android______________________________________________________________Elecraft mailing listHome: http://mailman.qth.net/mailman/listinfo/elecraftHelp: http://mailman.qth.net/mmfaq.htmPost: mailto:Elecraft at mailman.qth.netThis list hosted by: http://www.qsl.netPlease help support this email list: http://www.qsl.net/donate.htmlMessage delivered to turnbull at net1.ie