Hermes Lite 2
Hermes Lite is a project od DDC/DUC transceiver using as ADC/DAC cheap IC AD9866 from Analog Devices. Version 1 uses commercial FPGA module (hard to find these days) connected to ADC board, version 2
is more compact and all hardware is on one board. Link to project is here. Thanks to Steve KF7O for great project and organizing help for others.
I just built a clone of the board and added some more hardware around. My HL2 board comes from China, where the PCB was manuactured, assembled and tested. I got it via DHL for price around $200.
It was necessary to burn firmware into FPGA's flash (it should be done in China, but...), after that the board worked as expected. I just added low pass filters board to be sure the TX signal is
clean enough (control as in N2ADR design, filter design by YU1LM) and a 2m transverter (available from eBay from Transverters store for about $40).
First measurements show it is working as expected (HF board gives about 2W RF on each band, transverter up to 10W - sensitivity is great). I will publish some numbers when I finish the measurement.
At this moment I just add some pictures...
My goal is to become more familiar with SDR technology - HL2 is perfect in this point of view: proved design, no need for demanding SMD soldering, but still some skill needed / you don't buy already made piece of hardware.
I built already 2 pieces of Hermes Lite 1 in past, I like the compact design of HL2.
I am primarily CW QRQ operator, so I like "perfect CW". Especially any latency between paddle and my ears is inacceptable.
My interface does following: generates CW sidetone (instead of PC) based on key/elbug input, generates VOX/PTT signal for HL2.
and mute PC audio when PTT is active.
CW interface circuit diagram