Quad-AMBE3000

A PCB for four DVSI AMBE-3000R (or AMBE-3003) Vocoders for use with WebSDRs/Audio transcoding.

Using four AMBE-3000R parts was cheaper than using a single AMBE-3003, which was the original plan. This is useful for VHF, UHF, SHF WebSDR platforms that decode D-Star, DMR, YSF, NXDN, P25, etc. A soft-codec approach based on mbelib can be used, but appeared to give poorer decode audio when tested.

Using four AMBE-3003 parts gives a total of 12 similtaneous transcode streams. the '3003 part requires 1V9 instead of 1V8. You may also benefit from increasing the S_COM_RATE to 921,600kbps, by changing S_COM_RATE0 from low to high. See the devices respective datasheets.

The DVSI AMBE parts can be purchased in low volume from the DVSI Inc. Hardware Product Pricing page. You will need to create a purchase order to buy from DVSI.

Assembly

The design schematic include details for JLCPCB assembly, who assembled mine. You'll likely have to reflow the DVSI AMBE-3000R part yourself, which I did with a PCB reflow hotplate, but you can do any way you wish.

Each schematic component has a JLCPCB Parts/LCSC part number (Cxxxxxx), which can be exported to the BoM using the extra field "LCSC".

Schematic

PDF schematic can be found here

Images

3D Renders