[hpsdr] Issue with CW mode on Ozy/Penny/Mercury boards

Ramakrishnan Muthukrishnan ram at rkrishnan.org
Mon Feb 24 07:02:51 PST 2020


I thought I should write a short note to the list on how it got resolved, though not many may be interested in Ozy at this point.

It turned out that the FPGA inputs GPIO22, GPIO23, GPIO24 were floating at the input of U13, the buffer IC (74LCX541). That was because the R12 (the now defunct RC network package), which has a strange package form factor, wasn't making contact to the PCB pads. Once that was found, it was easy to fix the problem. Also it turned out that contrary to what I thought, regardless of the mode, these pins were asserted.

The usual multimeter tips turned out to be a little big for these ICs. Attaching a sewing needle helped a bit.

A big thanks to George Byrkit K9TRV for some great education via email while doing the debugging. Because of this issue, I am now setup with Visual Studio for building KISS Konsole/PowerSDR, Quartus 13.0 Web edition for building Verilog code etc.

Need a few more days of effort before I can be on the air with these boards. But I am almost there.

PS: The list archives return some search results, but returns an error while clicking on the returned links. List admin, please take a look.

--
73
Ram, VU3RDD
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