Duplex MMDVM_HS Dual-Hat (with OLED Display)

Experience next-level digital voice operation with this full-duplex MMDVM Hotspot system, professionally assembled and fully configured for true plug-and-play operation.
Using a duplex MMDVM_HS board with dual ADF7021 modems, this hotspot supports both DMR time-slots simultaneously and provides excellent performance across DMR, D-Star, System Fusion, P25 and NXDN.

Each unit is delivered fully built, configured, and tested, running the latest Pi-Star firmware on a Pi Zero W, all housed in a robust metal enclosure with dual antennas included. Simply power it up and start communicating—no complex setup required.

Perfect for home, travel, mobile use, or as a dedicated personal digital repeater.

Included With Your Hotspot

• Fully assembled and tested hotspot

• Updated MMDVM_HS firmware

• 32 MB SD card

• Pi-Star preloaded and customised with your details

• Raspberry Pi Zero W included

• Strong metal enclosure with clean finish

• Two antennas (TX/RX)

• Original Raspberry Pi power supply

• Plug-and-play operation — minimal setup needed

• Clear instructions included

  
  

Simplex VS Duplex Hotspots

Technical Specifications

Board Type:
• Duplex / Full-Duplex MMDVM_HS “Hat”

Modem Chipset:
• STM32 microcontroller
• Dual ADF7021 transceivers

Supported Digital Modes:
• DMR
• P25
• D-Star
• System Fusion (YSF)
• NXDN

Operating Frequencies:
• VHF/UHF (depending on configuration)

RF Output Power:
• Up to ~10 mW

Antenna Connections:
• 2 × SMA (TX and RX)

Indicators:
• LED status indicators — TX, RX, Mode, PTT

Display:
• OLED 3 Display

Power Requirements:
• 5 V DC (stable supply recommended — official Pi PSU included)
***Kindly note that a normal cell phone power supply will not work as the current is too low***