Hi all, I looked at the RF design:
Starting with the HMC5416 RF Tx/Rx switch and am puzzled that 4W on 50ohms is 20V ie. 40V peak to peak into that GaAs device. I did look at the data sheet matching in/out circuits and noticed a DC connection between ALL Rx, Tx and Ant. pins, through inductors. Is this necessary? Then, the RF output: No filtering straight out of the synth chip. On the Rx side: Again, no filtering and no AGC. Does this mean an adjacent strong signal will de-sense it badly. On the PCB layout is there provision for filters. Alan VK2ZIW On Sun, 1 Dec 2019 11:43:27 +1030, David Rowe wrote > Hello David > > Travis Goodspeed had a link to the M17 project in his twitter feed. > Think you might find it interesting, WOJCIECH SP5WWP is using codec > 2 in his 70 cm M17 radio system. He seems to have an RF background from > his Linken profile https://www.linkedin.com/in/wkaczmarski/ and he > has been working on M17 for a year and plans to open source his > hardware and software, so now is going public to get feedback. > Thought it would be nice if you could pass along the following > links to people who might be able to tell him about any pitfalls in > his current designs. > > Github page https://github.com/sp5wwp > > Blog page https://teletra.pl/M17/ > > Forum page https://teletra.pl/forum/ > > This link gives a quick overview of the status of the project > https://teletra.pl/M17/blog/summary > > Like that he is developing a handheld, repeater and hotspot, so is > thinking about how all the elements will come together as a system. > > 73 Carl > VE3APY > > _______________________________________________ > Freetel-codec2 mailing list > [email protected] > https://lists.sourceforge.net/lists/listinfo/freetel-codec2 --------------------------------------------------- Alan Beard OpenWebMail 2.53
_______________________________________________ Freetel-codec2 mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freetel-codec2
