Notes on project Gamma - The Power Supply

Notes:

The Quadra, which runs 8 x MRF-150 and is rated for 1000 watts SSB uses a 2.7kVA power supply that delivers 50 amps at 48 volts. That equates to 2400 watts, which implies an efficiency of 41.6%. There is probably some headroom in the design however, and efficiency is likely more like 45%.

Elsewhere, in several places, I have seen suggestions that MRF-150's require around 5-5.5 amps per device at 50 VDC. This implies a supply capable of 80 amps at 48 volts for 16 devices, or about 4000 watts.

CCI specs their EB104 board at 20 amps, which is consistent with the above.

Back of the envelope, assuming 45% efficiency, 1500 watts of output requires 3,333 watts of input.

In Helge's QST article, he builds a 1500 watt amp using 16 MRF-150's and rates his power supply at 2800 watts.

It turns out that there are plenty of 48 volt power supplies on eBay. They mostly come out of telephone switches, so look for names like Nortel, Lucent, Cisco, etc. I was able to buy a Lucent 4000 watt 48 volt supply for under $50 shipped to my door.