Dx PS30SWII Switching power supply - review

The additional power supply arrived yesterday and I had chance to connect it to the HF rig and try it out.

DX PS3-SWII Front Panel

Construction

The power supply is housed within a black coloured compact aluminium box which is essentially a huge heatsink. 

It measures 190 W x 69 H x 181 deep (millimetres) and weighs approximately 2.3 kg. The front panel housing all the controls and some connectors is held to the box with 4 screws.

The rear panel comprising a pair of screw terminals, a fuse, a selector switch, mains power connector and a small extract fan is similarly attached.

Connectors

On the front panel are snap in spring connectors to supply 3 amps and a cigar lighter socket to supply 10 amps.

On the rear panel are two large screw terminals capable of supplying the rated 35 amps (probably a lot more)

Controls

There are two rotary controls; a detented voltage adjustment from 0 to 15 volts which is at 13.8 volts when in the detent and a noise offset control. The latter is adjusted if you find that any birdies appear within the band you are on. Simply turn it and the oscillator frequency is changed so it goes out of band. This is patent pending according to the  instruction sheet.

There are two switches one to switch the meter to amps or volts and the other to switch the unit on or off.

There is also a large illuminated dual purpose meter on the front panel. This seems to be lit by white LEDs and gives a pleasant glow.

On the rear panel is a further switch that sets the output voltage at 13.8 volts or variable so it can be controlled by the front panel control. I set it at fixed 13.8 volts. 

Operation

I connected the FT-450D to the rear connectors and powered it up. I have it mounted on the desk in fingertip reach. The noise of the fan is very low and it is on continuously. This is not irritating at all, when compared to my Watson which sounds like a jet taking off sometimes, so quite happy to leave it there for now.

I set the rig to 100 watts output and called CQ on SSB and there was no increase in noise. Then I set the rig to 35 watts and played digimodes for a few hours. I was surprised that the only noise was coming from the rig's in built fan. I hadn't heard this before as it had always been masked by the Watson power supply. In all this time the power supply didn't get warm at all.
My Fujitsu laptop fan actually is louder than the power supply so I'm pleased with it.

I disconnected the antenna and tuned around all the amateur bands and couldn't detect any noise coming from the switched mode power supply. So I haven't been able to test the effectiveness of the noise offset control.

Conclusion

This power supply is a well made, almost noiseless addition to the shack of G8YPH and I hope it gives many years of use to the radio station. 

Bought from Moonraker during one of their 15% off offers on August 2015 bank holiday weekend for £59.00