[Elecraft] KPA1500 Power Supply Fan Noise

[Dan Atchison]

My KPA1500 s/n 156 had such a problem with PS audible noise.?? It was 
fixed with two mods available from Elecraft, one a new LED board and 
another with a resistor addition to the MeanWell power supply output?? 
The latter was probably not associated with noise but it's an addition 
that was not on my #156.

73,
Dan -- N3ND

On 6/11/2019 7:51 AM, Roy Koeppe wrote:
> Eric -- this is not at all normal! My PSU is quiet...hardly hear it 
> from under the table. I understand Elecraft changed to much quieter 
> fans maybe two years ago. But even so, perhaps the voltage to your 
> fans has soared way to high? I haven't looked at the circuit driving 
> them. Maybe lost regulation, etc.
>
> 73,???? Roy?????? K6XK
>
>
> Apparently I was not clear enough in my message.?? It is the PSU fan noise
> that is deafening, not the RF deck.?? Like Peter, my PSU sits on the floor
> underneath a wooden operating desk that holds the rest of the K-line.?? 
> The
> noise from the PSU is high-pitched and piercing.?? The only thing I can
> liken it to is a four-rotor Mazda prototype IMSA GTP race car from the
> early 90s.?? Brain-piercing, tear-your-hair-out, heard-from-every
> room-in-the-house louder than hell, and has been so since the day it
> darkened my doorway--with the RF deck at idle.
>
> 73 Eric WD6DBM
>
>
>
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