Adequate Power

Getting the wave-2 chipset working over the air has been surprisingly challenging.  Cabled transmission (SMA cables) to an AP was working mildly well,  and over the air (OTA) transmission was just not working at all.

We decided to investigate the power requirements of the chip. We were told that power draw would be up to 14 watts. We’ve seen PCIe cards draw 12W from the PCIe bus before. This radio has power connector points on the board for an extra 5v lead.

To our surprise, hooking up a 5V lead from a floppy drive power header on the motherboard was inadequate. So we attached multi-meters and saw that it was pulling the 5v line down to 4.22V and drawing 2.5amps. Holy cow!

We decided we needed power off of the 12V line. Soldering up a 15W linear regulator, we got a much steadier 5V supply to the card. It worked!

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Multi-meters connected to measure current draw and voltage levels
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Heat sink on the DC regulator

This time,  we were able to connect a station to the AP and start a 850Mbps download without any trouble. Whew!