From what I can see, the AMBE chip is only needed for Digital Voice mode.

If that is really the case, it should be possible to build a D-RATs/Digital mode adapter for existing FM gear usign a GMSK modem.

I have not found any information on the Wild Wild Web for such a project though.

Any one know of any?

Regards,
-John

You are correct on all counts.

Hello John,

You're correct in that the DVSI AMBE chip is only needed for the Vocoder section but it wouldn't surprise me if many implementations EXPECT to see the AMBE chip there even if it's not being used. The DIY market for Dstar is very robust and with various GMSK modem boards out there now (even all SW versions too). I don't see why this wouldn't work but you might need to work with the GMSK modem vendor to get the SW to work properly.

--David
KI6ZHD

On 3/29/2015 10:34 AM, David Ranch dstar@... [d-rats_group] wrote:

Hello John,

You're correct in that the DVSI AMBE chip is only needed for the Vocoder
section but it wouldn't surprise me if many implementations EXPECT to
see the AMBE chip there even if it's not being used. The DIY market for
Dstar is very robust and with various GMSK modem boards out there now
(even all SW versions too). I don't see why this wouldn't work but you
might need to work with the GMSK modem vendor to get the SW to work
properly.

I definitely will try the software route. I am looking for Linux based operation.

I found: and . I do not see any support for GMSK there.

The looks more promising. Even though it targets a Raspberry pi, I should be able to also use an x86 linux system instead.

The thing there is that I do not want to use the c2 stuff.

I have subscribed to the gmsk_dv_node list and asked about the USB drivers. No response so far.

I am also looking at the freestar * solutions. There site only seems to have ISO downloads.

It seems to me that the radio/computer portion should be similar to a repeater setup, but only repeating messages from a local ratflector instead of over the air.


I am finding a lot of dead links in this search.

Regards,
-John

开云体育

Hello John,

?

I definitely will try the software route. I am looking for Linux based
operation.

I found: and
. I do not see any support for GMSK
there.

That's a copy of Tom Sailer's Soundmodem.? It was impressive for it's day and it's diagnostic views are still unsurpassed in some respects but it hasn't been supported for years and there are several alternatives out there now that are VASTLY superior for actual decoding. Here is a quick breakdown of what's out there:

??

But like you said, none of these do GMSK

The looks more
promising. Even though it targets a Raspberry pi, I should be able to
also use an x86 linux system instead.

Yes, that looks pretty good for a software based GMSK modem!

The thing there is that I do not want to use the c2 stuff.

I have subscribed to the gmsk_dv_node list and asked about the USB
drivers. No response so far.

USB drivers?? I don't think you've stated your question properly.? You're looking for a full Dstar protocol stack to run over this GMSK modem and that looks to be here:

??

I am also looking at the freestar * solutions. There site only seems to
have ISO downloads.

ISOs are probably meant to just boot from.? Try citing some of these URLs and we can look at them


--David

On 3/29/2015 4:52 PM, David Ranch dstar@... [d-rats_group] wrote:

I am also looking at the freestar * solutions. There site only seems to
have ISO downloads.

ISOs are probably meant to just boot from. Try citing some of these
URLs and we can look at them.

It looks like I basically need the software listed in:



The difference is that I do not want to create a full duplex repeater, so I need to configure things differently.

Regards,
-John

开云体育

Hello John,

Yes, this looks like a great place to start and considering there are Rpi & BeagleBone images available, that might be a super easy way to try.? The thing you'll need to figure out is how get D-Rats to use the available Dstar stack.? I suppose two serial ports could be used but there must be a way to interconnect them virtually.

--David

On 3/30/2015 9:52 AM, David Ranch dstar@... [d-rats_group] wrote:

Hello John,

Yes, this looks like a great place to start and considering there are
Rpi & BeagleBone images available, that might be a super easy way to
try. The thing you'll need to figure out is how get D-Rats to use the
available Dstar stack. I suppose two serial ports could be used but
there must be a way to interconnect them virtually.

From the computer API view, it seems to look like a repeater node, so by running a ratflector on that computer linked to that software, an unmodified d-rats client should just work.

The site is back up. They had a power failure over the weekend.

Unfortunately some of the products that would be of direct interest for this project do not appear to be available in kit or assembled form.

is a GMSK modem with a standard serial port. Should be easy to write a program to translate from a ratflector i/o to what gets transferred to and from the radio.

I can not find this product for sale though. Full schematics and such are available on the site.


is a re-implementation of the original GMSK node adapter. One modification of interest here is that it presents an RS-232 data port that outputs the same data stream as is available from the serial port of an Icom D-star radio.

I also can not find this product for sale either. Full schematices, etc are available on the site.

What they do have is the mini-hotspot, but that is missing the serial port and apparently needs a special USB driver, which limits it to Linux and Windows at the present time.

I can find other versions of that mini-hotspot for sale in the same price range. It seems that if I go the hardware route, a Raspberry Pi based solution is currently looking the most attractive.

Regards,
-John

There are a LOT of GMSK boards out there though a lot of them are moving away from plain RS232 serial ports just because no one has them anymore. Anyway, maybe the Moencomm boards will work:



Jim Moen is a very helpful person so you might want to run your idea by him and see if any of his products might fit.

--David
KI6ZHD