Wednesday, January 14, 2009
Satoshi, 7M3TJZ/AD6GZ's D-Star Node and DV Adapter
Satoshi Yasuda, 7M3TJZ/AD6GZ, has two different constructions projects available. The one that is the main focus of this yahoo group - the node adapter - is basically a GMSK smart modem tailored to D-STAR.
The node adapter has two modes - simplex and repeater. In simplex mode, node adapter only serves to decode/encode the GMSK modulation used by D-STAR radios and turn it into a bit stream that can be fed into a computer. In repeater mode, the node adapter serves as a bit regenerative repeater. However, while in repeater mode, the node adapter does not have the capability to pass any data in/out of the computer. So, in repeater mode, the node adapter can not be linked to any D-STAR gateways/reflectors. This node adapter has no provisions to convert D-Star Digital Voice To Analog Voice. This hardware software combination operates in 100% digital mode.
He began by looking into the UT-118 works. It is entirely of his own design. Mr. Yasuda is/was a member of the D-Star standardization committee.
The main component is the CMX589A GMSK modem chip. The same chip used in many
of the Icom radios.
Probably the next most important chip is the 18F2550 PIC that runs his firmware.
This takes care of formatting/ recognizing the actual D-Star protocol, USB
More information can be found on Satoshi's web site.
Mark, KB9KHM uses his node adaptor in simplex mode with his D-STAR Hot Spot software that Mark wrote to provide a simplex RF point of presence to the D-STAR network. (He uses his D-Star HT with the adaptor hooked to an analog radio's packet port to pass D-Star digitally to a gateway server over the internet.)
In this video, Erik Finskas OH2LAK, of Finland shows his D-Star Hot Spot / node adaptor while holding a QSO:
And here is a slide-show overview of the GMSK Node Adapter:
In a later revision of Mark's hotspot software he added a routine that provides a way around the combination problem repeater mode and linking. Now you only need one pic, as the data received can be sent back out like a loopback, while still keeping a data stream to external D-Plus gateways.
His AMBE DV adaptor on the other hand is a full blown adapter to turn an analog radio in to a D-STAR radio and does include provisions to encode/decode AMBE.
In this video Peter, DJ6ZR/AI4UE and Don, WD4CWE test D-Star on 6 meter and 10m with the Satoshi DV Adapter. With more info at http://dstarradioclub-international.com/default.aspx
Mark, G7LTT/NI2O also has had 10 and 6 Meter successful D-Star QSO's using Satoshi's AMBE DV adapters interfaced to two Yaesu FT-8900 quad band FM rigs.
Satoshi's AMBE DV adapter does decode and encode raw D-Star tailored GMSK unlike the the DV Dongle that Moe, AE4JY and Robin, AA4RC have in production.
Satoshi's does seem better suited for the D-Star to SIP translation project that is being investigated.