Notice： Tantalum capacitor filtering circuit, stable operation, can start up in 7x24 hours The DMR usage effect is very good Supports OLED screens and serial Nextion screens Paired with Raspberry Pi, it's ready to use Description: - 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. - An accidentially deleted 3v3 wire has been added back to the PCB layout. BOM, Mouser cart and stencil stay the same as for rev1.1. - The upper part is 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. Features: - High performance 32-bit ARM processor - 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 Note: 1. Hardware version 1.0, software version 1.4.17 2. Without shell 3. Not include the raspberry pi 4. The firmware is pre-loaded.Please do not upgrade the firmware by yourself. 5. No welding, welding and matching according to personal needs, cannot be plug and play, it is recommended to operate professionally. Package Included: MMDVM Hotspot Module +OLED +2 Antennas NOTE: Communication is the best way to solve the problem. If you have any problems after purchasing, please contact us in time, before opening return or case. Return policy ● If you need return, please contact our customer service representative, let us know the detailed problem. ● Select from the following 5 reasons.* The reason you pick has no impact on you or your refund amount, but it has a big impact on us as a seller. Other selected reasons may delay the refund process per an internal investigation and appeal to eBay. 1) Changed My Mind 2) Found a Better Price 3) Just Didn't Like it 4) Ordered by Mistake Payment & Shipping & Handling ● Item will be shipped within 24 hours after full payment is received(NOT counting holidays or weekends) Contact us ● If you are satisfied with the product you received,please leave us positive feedback and 5 scores DSR. ● Please give us the opportunity to resolve any problem. We understand the concerns and frustrations you might have, and will try our best to resolve the issues. ● We care about our valued customers, and will always try to help you. So if you have any problems, please e-mail us immediately.