[time-nuts] HP5370 power supply measurements

Poul-Henning Kamp phk at phk.freebsd.dk
Fri Jul 15 10:32:59 EDT 2016

In message <CANX10hCEfL7+svnWXrAzddyAt-rVrEKBjYEg=97fn59FozXQDA at mail.gmail.com>
, "Dr. David Kirkby (Kirkby Microwave Ltd)" writes:

>Surely one of the main  advantages of the SMPS route is the higher
>efficiently means less cooling air is required.  That means less noise.

Apart from a handfull of watts from the rectifiers, the heat you can
avoid with a better power supply is what is dumped into the cooling
fins on the back.

>I often here of people replacing fans with quiter ones, but I suspect that
>all they really do is reduce the airflow. I believe that most of the noise
>one hears is the movement of the air.

In my case the bearing is worn out and rattles.

As far as I can tell it is just a Pabst 80x80x38mm axial fan with
115VAC supply, so this is going to be my attempt at replacing it:


Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
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Never attribute to malice what can adequately be explained by incompetence.

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