New Version MMDVM HS Dual Duplex Hotspot Board Support P25 DMR NXDN With OLED 2 Antennas + Case For Raspberry pi Pistar ITEM NOT INCLUDE THE RASPBERRY PI Selling point : Our simplex and duplex systems all use an offset of 0, which is our duplex system. Regardless of simplex or duplex, the offset is 0. We are using high-precision temperature compensated crystals, so it is 0 We use high cost TCXO crystal with extremely low bit error rate, offset of 0, and frequency error of 0 Best version : 1.Latest version and the firmware is latest Duplex variant of MMDVM_HS_Hat This PCB uses the MMDVM_HS . It has two ADF7021 onboard and allows for duplex operation with two time slots on DMR. The default bit error rate is less than 5%, and the default offset is 0. If the bit error rate is more than 5%, as long as the signal can be received, it can be corrected by offset. Revision 1.3 An accidentially deleted 3v3 wire has been added back to the PCB layout. BOM, Mouser cart and stencil stay the same as for rev1.2. Features: - Fully tested - Supports DMR, P-25,D-Star and System Fusion - Onboard LEDs to show status (Tx,Rx,PTT,Mode) - Up to 10mW RF power - SMA antenna connector,Antenna included - Mounts cleanly on all current Raspberry Pi's including the Pi Zero - The firmware is pre-loaded and is easily upgraded via software. - Open source 3D printable case available - UHF 430-450 MHz,433mhz and 900MHz VHF 144 220 Opera FREQ The upper partis TX,the lower is RX antenna. UHF+VHF SMA,antenna Modem select:STM32_HS_GPIO Set TX frequency,RX frequency TX,RX frequency had better 10M or more apart. SLOT1,SLOT2 support. Package List: - MMDVM duplex HotSPOT Module x1 - Antenna x 2 - SMA socket x 2pcs -Aluminum alloy shell _x000D_