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Question? Model a vs previous model?


gary limbert <kd8viq@...>
 

While I may be reading more into this, than what is actually happening, but if I could get some clarification to remove some of the fog or clouds in my mind.

Playing with D-star for some time now, and seeing how many of the devices are
moving to incorporate C4FM, P25 and other digital modes.  In making
this move of the baud rate on the new thumb drives will that allow this
new model to be later opened up for the other digital modes?  If it should allow them to open up for C4FM, P-25 or other digital modes, will those who have purchased the first batch before model a be stuck in D-Star Availability ONLY?

kd8viq@...


"John D. Hays" <john@...>
 

The ability to do vocoding for DMR, D-STAR, Fusion, P25 Phase 2, etc. is built into the AMBE 3000 chip.  The new Model 'A' only changes the baud rate that the serial port passes packets to and from the chip.  It does not change any other capability between the original and Model 'A'.

The 230400 baud rate is sufficient for all of these modes.  The OEM(s) we are working with are swapping out another USB AMBE-3000 device with the ThumbDV.  That other device was strapped at 460800 and they just want to swap it out.

It doesn't make sense for us to make 2 models, one strapped at 230400 and one strapped at 460800 so we are now making all units strapped at the higher baud rate. 

There is no secret, hidden, message here.  It's a simple baud rate change that we wanted customers to be aware of, nothing more.

Here is the math:

The fastest input from one voice stream is 128 Kbps (8000 samples per second at 16 bits). So 230kbps in is more than sufficient. The fastest rate out is Yaesu's full rate at 7.2kbps, DMR, Fusion half rate,  and D-STAR are at 3.6kbps. (This is for encoding, reverse for decoding.) There is only one packet stream, so you don't get any doubling of these numbers. 

There is literally nothing different than the selected baud rate, implemented in an update printed circuit board that changes what lines are strapped down.

The AMBE 3000 chip provides the vocoding, and only the vocoding.  The various protocols embed the vocoding in their respective data streams.  The 'devices' (e.g. AMBE 3000 boards, dongles, etc.) are not involved in the actual protocols, only in turning voice into AMBE and AMBE into voice.

Please view http://nwdigitalradio.com/john-speaks-on-dv-modes-at-microhams-2015 to see how digital voice systems are built up. 


On Tue, Jul 14, 2015 at 10:31 AM, gary limbert kd8viq@... [UniversalDigitalRadio] <UniversalDigitalRadio@...> wrote:
 

While I may be reading more into this, than what is actually happening, but if I could get some clarification to remove some of the fog or clouds in my mind.

Playing with D-star for some time now, and seeing how many of the devices are
moving to incorporate C4FM, P25 and other digital modes.  In making
this move of the baud rate on the new thumb drives will that allow this
new model to be later opened up for the other digital modes?  If it should allow them to open up for C4FM, P-25 or other digital modes, will those who have purchased the first batch before model a be stuck in D-Star Availability ONLY?

kd8viq@...



John D. Hays
K7VE

PO Box 1223, Edmonds, WA 98020-1223 
  


kd8viq@...
 

John;
 
    Thank you for the info.  While I wasn't trying to start something, sometimes change is not necessarilly good for us, and that was a concern that I had.  Yet since you show that we have nothing to worry about.  That is great. 
 
    I think I prefer having the lessor baud vs this newer rate,  Only time will truly tell. 
 
    While I have yet hooked the thumbdv into my computer.  I am looking forward to the experience. 

    Thanks again for GREAT WORK up front.
 
73
kd8viq