Monthly Archives: February 2011

No PCBs this week

I had hoped to be able to write about the new printed circuit boards this weekend, and maybe even show one built up, but they didn’t arrive. I had guessed that it would take them 9 days to get to … Continue reading

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FPGA Breakout Board Layout

Here at last is the printed circuit board layout for the FPGA breakout board. I’m planning a series of projects involving FPGA-based DSP for ham radio, and in order to build them, I need an FPGA and a PCB on which to mount it….

The goals for this layout constrained it to be a nearly single-sided layout, … Continue reading

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FPGA Breakout Schematic

Yay! Now we’re getting somewhere!

Here is the schematic for the FPGA adapter. Continue reading

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FPGA Breakout Design Decisions

To get to my goal of a DSP-based ham radio using an FPGA as the DSP, I first need a way to prototype with an FPGA. Available FPGAs all use modern, small packages such as QFNs, QFPs, and BGAs. I can’t imagine soldering wires directly to a hundred tiny pins, so “dead-bug” construction, with the chip upside-down on a piece of copperclad board, is out. I need a breakout PCB that holds the chip and brings out its pins to something more reasonable to work with. Continue reading

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The Plan

I’ve been thinking for some time about a DSP-based ham radio. After
considering and discarding more grandiose schemes, I was inspired by my
Norcal 40A. It and the original Norcal 40 are fairly simple and highly
reproducible (thousands were built). However, performance was not
sacrificed in the name of simplicity. Instead, the rig was carefully
designed to make the most of its NE602 mixers and crystal filter.

Why not try for the same goals in a DSP-based rig? In theory, one should
be able to subsume all of the IF and most of the RF and baseband into…. Continue reading

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