TagsA3PN250 adc AK5388 antenna breakout board business capacitor components construction CW delta-sigma design FDIM FPGA homebrew iambic IC iTead Studio keyer kit layout Morse code open source hardware PCB power supply ProASIC3 R2 radio receiver reviews schematic SDR Si570 Skywired software-defined radio soldering T2 test equipment theory transceiver tutorial USB vendor Verilog VFO
Monthly Archives: February 2011
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
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
Yay! Now we’re getting somewhere!
Here is the schematic for the FPGA adapter. Continue reading
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
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