Probing around for a powerful 48vdc supply solution I landed on a fair priced Eltek Flatpack2 rack unit. I know, it is an overkill for HAM shack use with its 8kw of DC output power. But as Jeremy Clarkson says; quote “Power and speed solves many things”  🙂
Anyways, this really is a part of a telecom UPS system, and telecom 48vdc system has negative distribution with positive common return rail. This is the opposite of what we HAM usual needs, so it has to be rewired, or re-bared rather.
This is a 2U rack module with a smartpack2 controller and 4 x Flatpack2 2000w HE rectifier units. You can run a single rectifier without the controller but it will default to about 53,5 volts. In order to change the operating output voltage, you need the smartpack2 controller.
With the factory access password, you can with the controller permanently write new settings down to the rectifier, and it will default to any valid voltage value. Of course it is possible to hack and reverse engineer the eltek CAN-bus protocol with other tools. I know the e-bike community has done it.

Here are some pix:

Smartpack2 rack without load fuses cover panel.

Smartpack2 rack without load fuses cover panel.

Smartpack2 rack unit

Smartpack2 rack unit

Original common positive (+) return bar.

Original common positive (+) return bar.

Rewired to common (-) negative return bar.

Rewired to common (-) negative return bar.

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Load fuses

Complete unit

Complete unit

PowerSuite for M$ windows config and monitoring tool.

PowerSuite for M$ windows config and monitoring tool.

Want one of these; search for “SGVU-L” @ ebay.
I am planning to use this in displaying RF-power measurement, but it needs some modifications. So stay tuned……………

Here is some more info:
I got this of ebay as a kit. PCB’s are very nicely build. Kit comes with LM3916 chips, which is a semi logarithmic VU meter LED driver.
Cascading six of these don’t really make any sense if you want to use it as a meter for readings.
So, I have replaced the LM3916 with one LM3915 logarithmic 3 dB/step driver chip for the ten first LED segments, then five LM3914 linear LED driver follows for the rest of LED segments.
Of course this is for one channel only, so you need 2 x LM3915, and 10 x LM3914 for doing both channels.

 

Will be participating in the ARRL EME 50 to 1296 MHz Contest this weekend. My band will be 144MHz in digital mode only. I have been working on giving my QRPp setup a 3dB boost for this weekend, but I had to abandon this due to mechanical difficulties. (Antenna staking hardware was not strong enough to hold the antennas straight, back to the drawing board I guess.) 🙂 My setup: Band: 144, mode: digital, antenna: 13,4dBd, power: 100-150w Good luck all!

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