Here is a couple of pictures of the rear of one of the power supplies. While my connections aren’t the most glamorous or sanitary, the DX can’t tell the difference!!!
In the picture of the entire rear, the lower three terminals are the 240V AC input single phase. Ground in the middle(green) and hots on either side. I’m using some #12 fine stranded cable for this.
The DC output is on the top on either side of the interface connector.
The blow up photo is the four jumpered pins needed to get the beast to turn on. There are four rows of 5 pins. The second row, short pins 3 and 4 and on the fourth row, short pins 3 and 4.
I have run this supply for well over a year, not every day but on and off and it works fine. I’ve run it with no load and have drawn over 55 amps with a BIG load, the voltage is VERY stable from no load to full load and I have not seen any oscillations regardless of load or no load.
I highly recommend some kind of strain relief on the cables since the plastic housing isn’t meant to be abused like this. I believe, one of the set of pins could be used as a remote soft start switch but I haven’t played with that yet. I believe there is also a “teaming†pin(s) that can be used to “link†more than one of these together for extra current or as a standby which is what we did in the computer world but that was all handled by the chassis and software.
I use some really nice voltage and current meters available from All Electronics. They have external shunts for 50A and 100A that can be mounted right near the power supply and the 50mv meter be mounted somewhere else, very worthwhile to look in to.
That’s about it, enjoy!!!!
Does some one have these 3 KW HP supplies for sale. Getting interested…in fact AM interested and building a 150 Watt 1296 EME capability for The 17 April Echos of Apollo event. First did 2 METER eme IN December.. the bug has bitten and I of course NEED MORE POWER! 73 Glenn b.
I’ve just acquired a couple of these – have you noticed any RFI issues at all? Chris G3WOS
Do a ebay search on “HP 3000W” and lots of them come up.
To date, I’ve not had any issue with RFI from these supplies however my antennas are 100 feet away from the supplies.
Have you tried a portable AM-SW radio somewhere near the unit?
Sure would be helpful to know if it radiates RFI.
It sounds as though it is not putting RFI on the AC line.
WDYT?
73, doc KD4E
doc,
No I haven’t tried the AM receiver by one, I don’t hear anything in my receivers. For $30, I would suggest you get one and try it.
Terry
Thanks for the pictures of that HP power supply.
It helped me to get this PSU up and running.
Nice and cheap PSU. It is quiet on the radio. Couldn’t find spuries and noise while using it.
73, Peter
HP Compaq 3000W PSU just purchased, my measurements
Output voltage 51.7 V (originally)
20 pin connector at output side, voltages related to the 0 V output
Row 2 pin 3: +4.3 V pin 5: 0 V
Row 4 pin 3: +4.0 V pin 5: 0 V
For Output voltage ON Pins 3 and 5 connected in both rows, then +60 mV.
There is no galvanic connection between pins 5 and the 0 V DC output. But n-channel MOSFETs can easily be used for the switching.
Tests with 1 A load current (51 W DC):
Output ON delay (when Pins connected): 5 ms
Output OFF delay: about 250 ms (output capacitor discharge, e-function)
Switching frequency:
Main: 50 kHz
Secondary: 385 kHz and 500 kHz
Output ripple: 70 mV peak (on 1 A load), mainly 50 kHz
Mains current (with clamp meter):
310 mA no jumpers, blower running
640 mA with 1 A load (35% efficiency)
Sorry I have no load resistance or PA for higher currents
Adjusting the output voltage:
This is possible through the potentiometer on the secondary board near the aluminium cooler, it is hidden by silicon glue. Turning clockwise: 50.4 V output. I would like to have 46 to 48 V for more safety for the PA transistors but this will be difficult.
73, Tom DL7AV
Hi, I sent you a reply some days ago. No interest in a professional statement?
73 Thomas DL7AV, AL7IB