Computer PSUs are pretty nice bench PSUs

When I got into ham radio I needed to power up my radios. Of course to power a 60W RF out radio you need quite some juice. Computer PSUs put out quite some juice. See where this is going?

Basic modding of computer PSU’s is terribly simple. You need a wire cutter, a driller, banana jacks and a soldering iron. Oh and duct tape. Duct tape is essential on any electrical work. The first thing you need to know is the pinout of the PSU. Most PSUs are ATX ones, which always have the same wire colouring. Black is GND, red is +5V, and etc. Second, you need to know that if you take a computer PSU out and try to turn it on it will look “dead”. But it is not. They need a certain wire shorted to GND in order to work. On ATX PSUs it’s usually the dark green wire, present on the motherboard connector. When IT guys try to check PSUs if they are working they do what’s usually called the “clip test” which is shorting the said pin with GND.

The rest is creativity. I usually drill wholes on the PSU case, mount banana jacks and that’s it. A ~250W, small, contained PSU with +5V and +12V (with also the options with +3.3 and -5V case that interests you).

Here are some pics of the works I did:

[In construction]

Now, onto the results. ATX PSUs voltage stability may vary. Both of the ones above show 12.7V with the radio on Rx and 11V while keying the radio at the full 60W. Do notice not all computer PSUs are regulated on the 12V line.

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