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Server power supplies are high-quality, heavy-duty, 24/7 supplies but inexpensive, less than AU $ 50. For amateur use, they have been specifically modified to turn them on and increase the output from 12.2 V to about 13.8 V.
Such sources are also found in cellular phone equipment, but at higher voltages 24, 36, 48, 60 V. These are good for powering transmitters.
As a technique to find information, look at the Google power supply model number (s) followed by images or videos for potential sites of interest. Searching for images is very powerful and takes past sales sites.
Apparently, many server supplies have additional airflow to keep them cool under load, so additional cooling can be prudent.
Some background on consumables was considered before what I could find for specific models. Some of the links take into account the RF noise from these switching sources, this is something to consider. Generally, they are high quality designs with low RF noise, especially when compared to laptop supplies, wall warts or common computer ATX supplies.
How important is voltage to an RF amplifier?
Should we sweat more than 13.8 V instead of 12.2 V of an unmodified supply? For the 80 W VHF RF MOSFET Amplifier Module RA80H1415M1 for 12.5 volt mobile radios operating at 144-148 MHz, the power output per V at max output is just over 10 W per V. 13.8 V with 12.2 V Yes, it sounds pretty reasonable, but does it matter in dB? So, 100 W – 85 W, 20 dBW – 19.3 dBW, only 0.7 dBW; indistinguishable ?!
Common slot power supplies
HP and others have been producing hot-swappable, high efficiency, common slot power supplies since approximately 2003. Consumables are standard size and all provide approximately 12.2 V up to 1000 W.
However, the ends of the consumables vary. All have 12V main supply. For control circuits, the secondary 12 V can be 2 A. Similarly, it can be 3 V and 3.3 V for logic circuits. There are a number of control signals I2C bus (SCL, SDA), analog and digital status pins (OK, Fault, etc). All of them have a pin to open them and some have remote voltage sensing discussed below.
The first task is to be able to turn on the source, usually by shorting two pins, but even that changes. Some consumables may use a mezzanine card with an on / off switch, cable connectors, and voltage display. These were used for Bitcoin mining and can be purchased for around $ 10.
External voltage remote sensing hacking
The simplest and safest way to increase the output voltage is to trick the voltage remote sensing into thinking that the output power supply is too low, increasing the voltage to the desired value; Normally 13.8V instead of 12.2V. Normally used to set voltage for lead resistance.
How far remote voltage sense works for a power source.
The general approach to sources is to short-circuit pins 31 and 34 to turn on the power supply. Then connect pin 32 with a resistor to ground to change voltage. The process differs slightly between models, so check out the specific pattern attacks in this blog post.
