AMBE.

[KA5PIU]

Hello.

Now that they have merged,,,,.
I have assembled several P-25 adapters, both for receivers as well as transceivers.
This is always the TI chipset, retasked for this service.
Several have said that this is not an option as the chipset is too expensive.
There was also question as to how I was able to get samples.
The answer to both questions is simple, XM.
Yes, the satellite service, XM, uses the AMBE codec.
I was very easily able to get a sample chipset by asking someone who was producing RF designs.
Since there are license issues I have never offered the basic design, but it is a very simple matter to reverse engineer this.
This was placed on demonstration at the hamfest in Temple as well as San Antonio.
It was designed and built for the purpose of allowing members of CAP to adapt member owned radios to P-25 and for no other use.
Look at how XM works, they actually use a dual mode AMBE chipset, it can easily be reconfigured for full duplex operation.
And, data rate is set dynamically, it is a software instruction.
Due to the fact that some ham had called up DVSI and had said all sorts of chit, around the time I was in "negotiations" with Motorola, I make it a point to pretty much stay very clean in this matter.
But, extract the data and audio chain and configure the chip, feed it P-25, and see what you find. 8)

[N2CHX]

Pics or it didn't happen.

Never mind, it just didn't happen.

[NQ6U]

WART

[kd8dey]

WART

http://www.compoundw.com/en/Products.aspx

[WA4TM]

Would that be a genital WART????:stirpot:

WART

[W3WN]

Would that be a genital WART????:stirpot:

Are you saying that... never mind.

I'm not entirely sure what merger ku goniff is talking about... and I'm sure he'll enlighten us soon enough... but I did find this reference: http://wiki.multimedia.cx/index.php?title=AMBE

I do find it interesting that the digital voice codec that D-STAR is using may also be the one XM is. If that is true, pending independant verification of course, then the complaints about D-STAR being so proprietary may have lost a leg to stand on. May.

[KC2UGV]

The argument isn't how expensive the AMBE2020 chip is. I mean, the chip is like $0.20-$0.75 depending on how many you get at once. The argument against AMBE2020 are:

* Single-sourced supplier. Should the one supplier go under, no more AMBE2020. Should TI break it's relationship, no guarantee the new chip will be drop-in replaceable.
* Inability to implement in software. With AMBE202, you can NEVER write a vocoder plugin to ANY system. So, no soft-only solutions.
* Inability to expand the vocoder, and improve on it for amateur needs.

[KC2UGV]

Are you saying that... never mind.

I'm not entirely sure what merger ku goniff is talking about... and I'm sure he'll enlighten us soon enough... but I did find this reference: http://wiki.multimedia.cx/index.php?title=AMBE

I do find it interesting that the digital voice codec that D-STAR is using may also be the one XM is. If that is true, pending independant verification of course, then the complaints about D-STAR being so proprietary may have lost a leg to stand on. May.

No, it still has the leg.

Show me an AMBE2020 vocoder I can use in Asterix.

Or, easier still: Show me the code to AMBE2020.

[NQ6U]

The argument isn't how expensive the AMBE2020 chip is. I mean, the chip is like $0.20-$0.75 depending on how many you get at once. The argument against AMBE2020 are:

* Single-sourced supplier. Should the one supplier go under, no more AMBE2020. Should TI break it's relationship, no guarantee the new chip will be drop-in replaceable.
* Inability to implement in software. With AMBE202, you can NEVER write a vocoder plugin to ANY system. So, no soft-only solutions.
* Inability to expand the vocoder, and improve on it for amateur needs.

Exactly. It's a proprietary codec, no one else can implement it either in software or hardware. That's the issue many hams (including myself) have with D-Star.

[KA5PIU]

Exactly. It's a proprietary codec, no one else can implement it either in software or hardware. That's the issue many hams (including myself) have with D-Star.

Hello.

Nail on the head!
First off, YES! AMBE is AMBE, TI does very little to customize the chip.
The early Sony units have the TI branded chips! just take a look.
Look up the TI application notes for the chip.
Now, pull the covers on the earlier M/A-Com talkies that do pro-voice, IMBE, but the chips sourced can to both.
There is but a few digits difference between the 2 chips.
And, no pictures hoopla, you can get your butt down to Texas and look at the thing.
In Dallas, Tanner Electronics on Valwood Parkway.
When I was in Dallas I was told that one machine was "closed" so I went to another and several hams were playing with the thing.
One went home and got a P-25 compliant scanner so to prove or dis-prove, it passed the test.
Houston, Electronics Parts Outlet on Fondren, the owners saw this And made a video of it.
The trouble with pictures, as was with the revolver, is that there is no end to it.
If it is connected to a talkie and P-25 is tuned, and it works, that is the gold standard in proof.
That is my position.