[Elecraft] KPA-1500 Fan Noise - measured (sort of)

[n7wy at rocketmail.com]

My measurements were taken with a microphone about 2 feet from the front panels of the components.   I wondered if W2PA’s alpha 89 was as quiet as he reported, so I thought I’d report on what I found -  

 

Ham shack in a finished (insulated drywall) room in a metal shed with equipment and HVAC off - 24 dBa

Above with Mitsubishi HVAC on - 29 dBa

HVAC was then turned off for the remainder of these measurements

KPA1500 PS fans on, RF deck fans off (step 0)  - 36 dBa

KPA1500 PS fans on, RF deck fans at step 1  - 40 dBa

KPA1500 PS fans on, RF deck fans at step 2  - 44 dBa

KPA1500 PS fans on, RF deck fans at step 3  - 50 dBa

KPA1500 PS fans on, RF deck fans at step 4  - 57 dBa

KPA1500 PS fans on, RF deck fans at step 5  - 59 dBa


alpha 87a (everything else off) - 50 dBa - the fans run at a fixed speed when mains power is applied


My experience for S&P CW during WPX is that the KPA1500 PA temp rose to about 64C so that the deck fans were at Step 2.   During a recent RTTY contest, the deck rose above 70C and the fans were running at Step 3 pushing a lot of warm air out of the vent holes above the heat sink.  


73 & YMMV,


Bob Rennard = N7WY