I recently obtained a NW Digital ThumbDV Digital Voice Dongle to use with DMR and DSTAR. It contains a built-in AMBE3000 vocoder chip. Paired with BlueDV software it turns a computer with a USB port into a device that can communicate on both DMR and DSTAR networks.
I am impressed with the quality of the hardware as well as the simplicity of use. It’s quite convenient to plug a dongle into the computer and be able to monitor and talk on DMR or DSTAR without a radio using just the computer’s speakers and microphone.
More information about the ThumbDV:
ThumbDV™ and PiDV™ Resource Page
More information about the BlueDV software:
BC890XLT Discriminator Tap
Last week I bought a used Uniden BC890XLT scanner and added a discriminator audio tap. Here’s how I did it:
The first thing to do was open the case. The outer sleeves come apart on the top and the bottom. There are 2 screws on each side and one screw on the back that I removed. I took both the top and bottom sleeves off to explore the inside, and discovered I only needed to remove the top to tap the discriminator audio. Once inside I found the location of the discriminator audio which is pin #10 of IC #3, 3359DA. Pin #10 is on the top right corner of the chip:
Rather than solder to the chip, I preferred to solder to the lead to the resistor at TP3 which is connected directly to PIN #10 of the IC. I put a 10K ohm resistor in series with a 10 Î¼F tantalum capacitor.
I wanted this modification to be removable so I didn’t drill a hole in the case. Rather, I ran a connected wire to the outside of the case through an opening in the side of the case.
I then ran the wire in the space between the case and the outer sleeve on the side. I then ran it around the corner to the back of the scanner. I connected the ground wire to the chassis via the screw that holds the accessory RCA jack. I put heat shrink tubing on the outside of the wires and connected them to a 1/8″ mono phone jack.
Radio Shack Part Numbers:
1/4-Watt 10K ohm resistors – #271-1335
10Î¼F Tantalum Capacitor – #272-1436
1/8″ Mono In-line Phone Jack – #274-0333
Assorted Heat Shrink Tubes – #278-1627