After the original posting last week, we had a number of off-list enquiries about the Remote Node Controller (RNC) for D-Star/FM dual mode working. Rather than respond individually, here is a diagram for the combined RF Switching / RNC circuitry:
http://www.g7lwt.com/documents/dv/Remote_Node_Controller_v1.jpg (BOM to follow) High level functional overview: http://www.g7lwt.com/documents/dv/gb3mi_gb7mi.pdf There are also a number of additional diagrams, a PCB layout and some software to be released shortly. Hopefully this diagram addresses most of the questions that were raised but the next update should cover all of the project details. Acknowledgements must be made for G1DVA and G8PWE's efforts in designing, debugging and documenting the RNC project. 73 de Darren G7LWT UK Interconnect Team from "Storer, Darren" <[EMAIL PROTECTED]> hide details 9 May (5 days ago) to Repeater-Builder@yahoogroups.com date 9 May 2008 18:44 subject Re: [Repeater-Builder] Dstar in an analog world - Ex-FCC Denies Petition mailed-by gmail.com Hi, here in the UK we first started dual mode (FM/DV) working a couple of months ago, using a common duplexer, antenna and frequency pair. GB3MI (FM) and GB7MI (D-Star/DV) were co-located both physically and in frequency. An overview of the approach can be seen here: http://www.g7lwt.com/documents/dv/gb3mi_gb7mi.pdf 2 weeks ago GB7YD (DV) and GB3NA (FM) were also co-located using the same approach. GB7YD is connected to the D-Star network via a G2 VoIP server and this PC is used to remotely control repeater switching priorities (Auto/DV/FM). The Remote Node Controller (RNC) connects to the G2 Linux PC parallel port, responding to command line instructions. V2 of the RNC software will interpret switching commands via D-Star RF (following the / parameter) from authenticated users only. This system of integration depends on constant CTCSS access (rather than UK style 1750Hz tone burst) to avoid GMSK activation of COS on the FM repeater. DV users are encouraged to use "auto detect" on their D-Star radios so they are aware of FM users. This is particularly important as DV mode carries priority by default, so rogue D-Star transmissions could potentially interrupt FM QSOs if DV users were not vigilant. The licensing authorities in the UK have been very receptive to dual mode working applications as the pressure on VHF amateur allocations is a particular problem near large conurbations. Dual mode working also facilitates the direct study and comparison of DV and FM propagation modes. 73 de Darren G7LWT
