[Elecraft] KPA1500 fan noise concern

[john at kk9a.com]

I imagine that due to the KPA1500's size it requires a higher volume of air
than a large amplifier would. Its small size and weight make it appealing.
The Acom 2000 has a control box that is separate from the amp so you really
never hear the amp run. I am wondering it something similar can be done with
the Elecraft KPA1500, perhaps an option like the K-Pod, so that the noise
source is further from the operating position?

John KK9A



Thanks for the offer, Clay. But we actually did extensive thermal analysis
of both the heat sink and fans, tested many different fan types and
configurations, and did comparative noise testing of the KPA1500 vs. a
number of other amps. 

As you allude to, there's no magic bullet. Heat must be removed, with
various physical and electrical constraints to be satisfied. 

We have some pretty amazing thermal imaging devices that we use to examine
heat signatures of electrical components. These were used during R&D, which
is how we determined that two LDMOS devices were far better than one for
heat distribution. We also used it to evaluate the design of our very
large/very thick copper heat spreader. On the production line, we review all
modules for hot spots during burn-in and make sure the cooling is working
perfectly (onset temperature, air distribution around modules, etc.).

Of course supplemental cooling of various types has been used with
amplifiers in the past. I believe we have a couple of customers and staff
experimenting with this idea, and anything that emerges will be posted here.

73,
Wayne
N6KR