How to turn PC Power Supply to power mobile rigs

Here is a guide to modify your PC power supply unit to power up your mobile rig. If its done correctly you can have a cheap (regulated) VDC power supply solution for your mobile rig to operate at home.

Step I

First get a ATX PC power supply from the nearest computer store. Price is around RM30-70.

PSU Power Supply ATX

Make sure it could supply sufficient current. Look at the label. We need at least 10-17amp at 12V for a sufficient operation of mobile rig. Lower Ampere rating means that your mobile rig cant transmit with a typical HiGH setting (50w).

Step 2

Look for ATX power connector. It should look like this.

ATX Connector Ham RaDIO

Look for black and green wire at the ATX connector. The wire position is 4th from the top left side of the connector and 4th from the bottom right side from the connector as pictured above.

Black wire

Cut the black and green wire. Trim all the other wires as we wont need them.

Tie both Black and Green wire together.

PSU Green and Black Wire Ham radio

Connect both Green and Black wire to bypass the PC Power Supply unit. Insulate it with some tape. and switch on the power supply. If the fan is running, that means you’ve successfully completed this step!

Step 3.

Ham radio power connector

Turn off the power supply. Look for HDD, CDROM power connector, as pictured above.


Cut all wire from the connector.

Ham radio power supply howto

Separate 2 black wires and one yellow wire. Combine both black wires together.



Look for an extra mobile rig power connector, this can be obtained from electronic shops car accessories, or car battery shop.

Connect the yellow wire (+12 volt DC) to the positive terminal at the power connector as pictured above. Connect both black wires together and put it to the negative terminal as picture above too.

Step 4

Amateur radio cheap power supply
Cut all unnecessary wires, connector, and leave the power supply with just the rig power connector like this. It will look much more presentable and neatly prepared.

Mobile rig 13.8 VDC power supply

You can test the output voltage of this power supply by testing it with Voltmeter/Multimeter. Here you can see that the power supply output voltage is about 12V, which is suffiecient to power a mobile rig (13.8V +/- 15%).

Step 5

Finally, connect the power supply to your mobile rig to power it up. Enjoy your QSO!

FAQ: Nice, but my mobile rig require 13.8VDC to operate, this PSU only supplies 12V, it won’t work
Actually it can work. Mobile rigs requires 13.8 +/- 15% VDC to work (check your rig manual). and that gives a range about 11.7V – 15.8V of stable voltage potential. So a 12V power supply with sufficient current (15A and above) is definitely sufficient to power the mobile rigs.

This howto has been translated directly from Malay version original article published in Forum Anak Perlis written by me.

You can refer there for a complete malay version of the guide if you find the English version is confusing.

12 thoughts on “How to turn PC Power Supply to power mobile rigs

  • kawan , boleh tak i tanya , macam cara awek ini boleh tukar 240v ac power supply to 12v DC power supply ?? i nak cari 12 DC v power supply untuk pc yang nak install dekat kereta saya . harap kawan boleh tolong saya terima kasih.

  • On back of my rig is written 13,8V and I use 12V (15A in peak max.) from PC power supply of 300W, I think 10 or 12A in normal work. But some friends told me that on this way I lose cca. 1W of power in output.
    I work on rig Maxon CM 10 CB radio.
    What is your opinion, is this true?

    Thanks & Regards

  • Mostly power supply pc ni operate on 8A to max 15A on normal condition but skrg ni kita dh boleh cari yg Ampere lebih tinggi di pasaran. It cost around RM50++ untuk set power supply 15A ke atas. My PC itself operated with original Acer power supply (20A).

    Slmt mencari


  • hehe, kena guna powersupply yang tinggi arus (tinggi ampere) kalau tak nnt mesti kelip2 kalau tx lebih tinggi dari 25watt

  • Salam nk tanya kenapa rig saya wayar merah/hitam (negative) jadi panas bila ON dan display LED dia tak menyala.. ada kemungkinan regulator terbakar?

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