Server power supply for CB/Ham Radio

I bought a couple of HP PL-18 750watt power supplies. I heard good things about these and watched plenty of YouTube videos on them.

They both have an output of 11 volts I have adjusted the power pot "which I believe is to be the power pot" from videos and pictures/diagrams I followed but I can't seem to get anymore than 11.5 volts out of them. I was hoping to get at least 12 Volts... 12.5 would be nice without the mod but none do 12volts out of the box or at least none of mine do. 11 volts is all I can get out of them.

I'm not going to do the resistor mod as I don't have the correct tools to be working on such tiny components and would likely end up bridging everything rendering it as trash.  

I expect a cheap standard radio like an old CB or PMR radio would be OK on 11 volts, there is plenty of current, but for a more state of the art HF transceiver which would be more fussy on voltage would want 13.8 volts. 

Would 11 volts be fine for radios? 

Is there another way to get the voltage up a bit more without the resistor mod?

I had a 40a one from Amazon can't remember the make but it turned up to 12.8v i think.
Don't know why but i never used it just tested it once and that was it.
Built it into a perspex case well i made the case with a fan and also terminals ans a V and Amp digital readout.
It sold very quickly on that auction site lol.

Maybe I'm not adjusting the right pot. It only seems to make half volt difference so 10.9v or 11.5v

I wonder if I am adjusting the right pot? I'm pretty sure I am but maybe some models have the pots in different places I don't know. 

It seems to be powering a car stereo just fine at 11 volts.

I am planing on stocking up on these before the rip off merchants catch on that they can be used for CB/HAM. 

All the ones I've tested have been 11 volts... might be worth buying another multi meter just to make sure I am measuring 11 volts and not 12 volts.

The radio gang have used them for years.
I have normal psu's a 60 a 45 and a 30amp +2 110amp leisure batteries as a backup but they also run my diesel heater here in the shack.
The 45 and 30amp are in the corner just in case.

Alan Pilot wrote:

The radio gang have used them for years.
I have normal psu's a 60 a 45 and a 30amp +2 110amp leisure batteries as a backup but they also run my diesel heater here in the shack.
The 45 and 30amp are in the corner just in case.

There not bad. They have plenty of protection on them, I have a few projects in mind. I'm building a couple of CB base stations so these will be perfect for that.

I also like my car stereo boombox builds so these are also good for that.

I also want to make a power strip of binding posts with one of those power supplies inside to power several transceivers rather than using big bulky power supplies that can just about deliver the current required to do that.  These server power supplies pack plenty of current so perfect for that.

I also want to build a couple of CB/HAM stand alone power supplies into some project boxes with toggle switch and binding posts plus LED light and maybe a volt meter readout display.

I'll only ever be drawing 30 amps and less. Most of the time it be less than 10 amps.

When I got this power supply I bypassed the two pads without using any resistor inline but I figured it be fine. I didn't have any resistors on hand but I have some now. I fitted a 510 ohm on to a toggle switch to turn it on/off.

All the HP server PSUs I have played with, no matter what the rated wattage(460W to 1200W), have all measured 12.0 to 12.1 volts on my multimeter. Not saying your meter might be out a little, it could well be mine as it's quite old, but results have always been consistent. My G90 on one of these reads 11.9 on it's display which is pretty close to my meter.

I don't twiddle the pots inside for more voltage, just leave as is. Depending on the input voltage tolerance of your radios, these can be just fine as they are. The only radio I have that didn't like working off of one is my 991A, the few others work just fine off of 12 volts.. Xiegu G90, CRT Electro UV, 4m ex-PMR unit, and 6900n. On the G90 I've played with input voltages from 9.5 to 15.0 volts with very little difference in transmitted output power between the highest lowest voltages, some other radios might have a more noticeable drop in output power.

My multi meter is pretty old and tatty so probably time to get a new one. It could very well be a bit out.

As for the pots, they are not worth adjusting so any others I get I will leave the power pot alone, it only offers 0.5 of a volt more.

Whats the deal with the resistor? so in order to get the power supply on you have to short two of the pads but some people use a resistor to do this, others just use a piece of wire, is the resistor necessary?


Edit: It would seem my multi meter is out. I will get a new one from Halfords tomorrow if they have any in stock. I need to get a pack of car fuses anyway so I'll pick up a multi meter while I am there.

Update... I bought a new multi meter while out today and the server power supply measures 12.8 volts almost 13 volts so all good.

As for the mods online to get 13.8 volts I just wanted to add although this works, its counterproductive because it can cause the over voltage protection circuit to kick in and give problems, leaving the PSU unmodified will be more reliable. They can still be turned up to 13 volts or hover just below which is good enough without the resistor mod.

12.8 was what i got on the one i had.
Couldn't get any more out of it and it had a marked pot PWR.

I made a start on building a case for my server power supply which is actually an old ATX case. Still much work to be done on it, I will do a bit more work on the case tomorrow.

Edited: No longer relevant.

This is the first power supply done, Just need to tidy up and fill in some holes on the casing, possibly give it a paint and put some rubber pads on the feet. The second power supply will have more on it and will be much bigger.

I had issues with not being able to find binding posts that have the insulation plastic on them to stop the center pin touching the metal casing so all the binding posts I ordered were completely & utterly useless for this project. I eventually found some old ones to use.

Here are the posts i used when i made a distribution box when i built my new shack and they are good quality.
 https://www.amazon.co.uk/gp/product/B07F6XJL9B/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Sorry, been a bit busy, am a few posts behind. Re the resister to short the two pads.. That is the method I have used since I first started doing this. It was the way everyone who had written up or made videos about were doing it. The first PSU I tried doing did not work with just a bit of wire shorting, with a resister it powered on. I am sure some models will work with just a bit of wire, there are a huge variety of HP PSUs out there.

Nice work repurposing a case for a case

Thanks...

The server power supplies I've tested so far have all worked with just a bit of wire but I will still add the resistor just encase it is needed rather than killing the power supply later on down the line from not using a resistor.
 
I will have a few more power supply builds on the way soon.