As I stated I do Not have a KPA500 It is in the future plans but I need to get some antenna work done first.
As I stated I replaced the Fans in my K3 I went with the Noctua brand because they are known for making a quality fan that is very quiet. New Fan: Noctua NF-A6x25 FLX Airflow: 17 cfm (29.2 m3h converted to cfm) Noise: 19.3db Speed: 3000 RPM (at 12 v) Static Pressure: 2.18 mm Current: 120 mA (.12 A) Original Fan: UTEC AT6015L-12L2B-ND2 Airflow: 15.4 cmf at 24.8db Noise 24.8 Speed 3000 RPM (at 12v) Static Pressure: 2.21mm Current 100 mA Yes I hear the air rushing but not the bearings ________________________________ From: Jim Brown <j...@audiosystemsgroup.com> To: elecraft@mailman.qth.net Sent: Tuesday, June 3, 2014 2:21 PM Subject: Re: [Elecraft] KPA-500 fan noise On 6/3/2014 7:19 AM, Harry Yingst via Elecraft wrote: > Replacing the fans was a worthwhile improvement and made copy easier. Something does not compute. The fan in my KPA500 is pretty quiet on RX, and only gets loud during long transmissions, continuing for a short time (a few seconds) after that. How does a fan that is noisy only on TX make copy difficult on RX? Another thing that doesn't compute is that a lot of the noise I'm hearing is air flow. Perhaps the replacement fan is running slower, which would reduce air flow, which would reduce cooling. Again, I would approach all of this with great caution. Cooling of power devices is as important an element of the design of amplifier as any of the rest of the circuitry. I think it's a mistake to think that we hear the fan because it's a "cheap" or inferior one. We hear it because it's working. 73, Jim K9YC ______________________________________________________________ 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 hlyin...@yahoo.com ______________________________________________________________ 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
