GSM MS boards on clearance: FC Caramel2

Hello GSM MS communities, I have a large inventory of FC Caramel2 boards that are in need of loving homes. I mean these boards: https://www.freecalypso.org/members/falcon/Caramel2/c2-fully-assembled.jpeg For those who are familiar with FCDEV3B, Caramel2 boards are very similar: all FreeCalypso tools work exactly the same (even with the same -h fcfam target selector option), firmware functionality works exactly the same (fcdev3b and tangomdm fw builds are made from the same source, just minor electrical diffs between the two boards which the fw needs to know about), same AT command interface, same rvinterf, same everything. Vadim (fixeria) recently told me that he found FC to have better CSD support than any other commonly available commercial GSM modem - this aspect will work exactly the same on C2 as on FCDEV3B. And for those who have an irresistible need to be naughty boys and run naughty software, OBB can run on Tango/Caramel2 hardware too: https://gerrit.osmocom.org/c/osmocom-bb/+/34297 The main diff between FCDEV3B and Caramel2 is that C2 came out a little worse in terms of quality: * FCDEV3B analog audio circuits (loudspeaker and mic) came out very clean despite no special effort at design time: I never hear any "buzz" from rectified GSM RF in FCDEV3B analog audio. OTOH, with C2 the audio is dirty by default, and to get it mostly-clean, I have to insert a long coax between the antenna connector on the board and the actual antenna, to move the radiating element away from the analog audio circuits. * LEDs: the single green LED on FCDEV3B indicates 100% reliably if the chipset is switched-on or switched-off, but Caramel2 board LEDs sometimes exhibit erratic behaviour as a result of wayward current paths, as I explain in the Status Report and User's Guide document: https://www.freecalypso.org/pub/GSM/FreeCalypso/Tango/Caramel2-SR-UG-v1.2.p… Seeing that Caramel2 design is flawed, I won't be making any more of them: *if* I decide to produce another board in the future with similar functionality, it will need to be a new design, adding LVC buffers for proper PPD support (partial power-down) and reworking the audio circuits. In this light, the existing inventory of C2 boards needs to be put on clearance - they are just gathering dust right now, but they should be perfectly suitable for more casual users with less stringest quality requirements. I have enough stock to supply 12 complete kits consisting of: * Caramel2 main board; * FT2232D-based DUART28 adapter board; * Power adapter from universal AC (worldwide voltage and frequency range) to 3.6 VDC; * Possibly FC-HDS4 headset and quadband GSM antenna. Once again, this board is a *clearance* item - no more will be made, but the already-made ones are looking for loving homes. *IF* there is any community interest in these boards, I would be happy to ship a few to Sysmocom, to be further distributed via the webshop. It would also be helpful if those who are interested in these clearance boards (if any) could state what they would consider to be a fair price for a full kit as described above. M~ P.S. If anyone still does CalypsoBTS hacks, these boards would NOT be a good choice for it, as the Rx SAW filters are totally inaccessible to rework - all 4 SAW filters (for full quadband Rx) are integrated into a monolithic chip-like module from Epcos, which is then embedded into the TR-800 module which is not amenable at all to rework. However, if you merely wish to see what's inside that TR-800 module, without modifying it, we have published results of a complete PCB reverse eng job on it: https://www.freecalypso.org/pub/GSM/iWOW/TR800-reverse-eng-gerbers.tar.bz2 https://www.freecalypso.org/pub/GSM/FreeCalypso/Tango/FC-Tango-netlist.tar.…