Manson EP925 25 Amp PSU

Just taken delivery of a Manson EP925 25 Amp power supply. It was purchased as 'new' from e-bay for £50 (May 2012), although from a private seller it came in its original and very old box but has never been used, if it has they used cotton gloves and cut the plug off and re-stripped the mains lead so I don't think it ever saw 230V.

First thing to do was to fit a plug and fire it up. Harri (only four but good with a pair of snips!) assisted and we had it humming away in no time. Attached a set of leads and found the first problem - the red and black screw retainers on the main output are not removable so I had to cut my circular connectors to be spade connections - not a real issue just a slight annoyance.

Connected to a rig and using 100 Watts of CW for 20 minutes there were no issues at all and the fan kicked in after 15 minutes but the unit was still cool. The fan could only just be heard with headphones on so pretty quiet.

Next thing to do was to take the lid off to check inside - Don't do this yourself unless you know what you are doing - there is 230 V in there! I did it when Harri was out of the house to be safe!!

I will be reviewing the mods provided by PA0FRI here, they look like sensible ideas.

So what did I get for my money....

Well you can see the generous heat-sinking just after the main control board/front panel. This houses the rectifier and the power transistors and the thermistor that controls the fan.

The transformer is a hefty beast and you can not buy one in the UK on its own for less that 100 GBP so this was good value. The fan is nice and large but it is really trying to cool the heatsink and not the transformer but I guess it does its job pretty well.

Now you don't see capacitors that size every day (47,000uF) they used to be so common when linear PSUs were all we had and great to see again...

ooops...... have a good look at this picture and you'll see the transformer is no aligned to the rest of the PSU - it looks like the chassis has taken a hit and the transformer carried on moving when the chassis stopped!!! This may have happened at any time. I've checked everything around the transformer and all is in good order.

It does show that the transformer should really be mounted on a solid chassis rather than thin mild steel but it's not and issue and I know it works.