Pro Audio Eng PAE-Kx33 Owner's Manual

Owner’s Manual

Rev 1.9

November 20, 2017

Pro Audio Engineering

PAE-Kx33 Low-RFI AC Power Supply

Thank you for purchasing the PAE-Kx33 Low-RFI AC Power
Supply.

The Kx33 was specically designed for the needs of high-performance
HF transceivers and communications equipment requiring a low-noise
source of DC. It is perfect for use with any device designed to operate

from DC 12-14 V at up to 4 A.

This supply features an innovative design which inherently minimizes
RFI. In addition the Kx33 features multiple lters to further reduce
emissions. The result is a power supply offering the small size and
light weight advantages of a switching supply without the common
disadvantages of RF noise, poor regulation and others. For full
information on its specications, design and performance capabilities,

please visit: www.proaudioeng.com

We welcome any and all comments regarding the design, operation or

performance sent to: [e-mail]

Howard Hoyt
WA4PSC
www.proaudioeng.com

IMPORTANT NOTES:

This power supply must be operated from a 50 Hz ~ 60 Hz power
source between AC 100 V and 250 V ONLY. Operate in an
environment away from direct sunlight or moisture. This supply should
not be used to directly charge a battery, damage, injury or re may
result. Failure to observe these constraints will result in voiding of the

warra nty.

Operation:

We suggest you plug the PAE-Kx33 power supply into an AC source

before turning on the attached equipment. If you are using the Kx33
to power more than one piece of equipment at the same time, turn on
the one with the largest power requirement rst. For optimum noise
elimination it is useful to place the supply at the full DC power cord
length away from the rig being powered.

The Kx33 is rated at 4 A output, but will produce considerably
more for a period of a few seconds. This allows it to drive large
capacitances and transient loads without current fold-back.

The Kx33 offers comprehensive protection circuitry including in­put over and under-voltage, output over-current, over-temperature
and short-circuit protection. These have been incorporated into the
Kx33 to protect your equipment, but they should not relied on as a

replacement for proper wiring or fusing.

At loads less than 25 mA the Kx33 enters a skip-cycle mode in
order to maintain voltage regulation. When in this mode there can be
ad ditio nal noi se on the ou tput. For lowest noise it is rec ommende d that
a load of greater than 25 mA be maintained. This is standard behavior
for most switch-mode supplies.

Some antenna systems, especially end-fed antennas will encourage
common-mode coupling through the power supply. This can
result in an apparent increase in noise, but thanks to the Kx33’s
very low input to output coupling, it is easily remedied by the
use of a common-mode choke. This can be made easily by

running the DC power cable 3-4 turns through the Snap-It core

provided with the Kx33. If additional cores are needed Pro Audio
Engineering offers a range of Fair-Rite products at very low cost:

https://proaudioeng.com/fair-rite-ferrites/

Please read the following section on RFI and AC power
supplies for more information.