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Converting the HP ESP120 Power Supply
24 August 2015 | by Quick notes on converting the HP ES120 2950-watt blade server power supply to run “48-volt” amateur radio amplifiers. The power supply I have has a slightly different in configuration from the one described by W8ZN on the K8GP site.
I picked up the power supply on good terms at Dayton some years ago and finally managed to get around to hooking it up after I put two 240-volt, 20-amp circuits in my shack this spring/summer. I used a molded air conditioner extension cord with the female end cut off to attach it to the wall. Hot-ground-hot is the wiring on the AC input side. On the output, there is a jumper block and two pairs of blade connectors, with one pair being positive and the other negative, strapped together. In the middle of the output there is a jumper block.
Here is where the steps differ from the W8ZN steps: instead of shorting two pairs of pins together, this power supply requires three in a line to be shorted together. It’s visible in the photo below, I think. The center row.
I’m getting 51.4 volts unloaded. Load will be described in the future as it comes to be…
5 Responses to “Converting the HP ESP120 Power Supply”
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i have this power supply and configured same as reccomended but when dc current pulls over 20 amps HP esp tripps over current and i must recycle the switch that connects 3 pins together.
Turns out device was triping due to RF being senced by power supply. No longer tripps ,i placed ferrite chokes to a/c power cord and unit no longer shuts down.
WELL FORGET ABOUT MY FIRST TWO POSTS. LOOKS LIKE I WAS PREMATURE ABOUT SHUT DOWN PROBLEM FIX. CAME TO RADIO ROOM AFTER I GOT BACK FROM SHORT TRIP AND WENT TO RADIO ROOM AND MY SHUT DOWN PROBLEM HAS RETURNED. AT THIS TIME I CANNOT USE MY LDMOS AMP UNTIL I FIGURE OUT WHATS GOING ON. ANY ONE GOT ANY IDEAS?
What is the location of your antennas relative to the amp cabling?
Have you checked the quality of your grounding system?
Where can I find service information (Manual) for the HP ESP120 power supply?