Duplex version MMDVM_HS_Hat This PCB uses MMDVM_HS. It integrates two ADF7021 chips and supports dual-slot duplex operation in DMR mode. The default bit error rate is less than 5% and the default frequency deviation is 0. If the bit error rate is higher than 5%, it can be corrected by adjusting the frequency deviation as long as the signal can be received. Fully tested. Supports DMR, P-25, D-Star and System Fusion (Fusion) protocols. Onboard LED indicators show status (Tx, Rx, PTT button, Mode). RF output power up to 10mW. SMA antenna interface, antenna included Mounts neatly on all current models of for Raspberry Pi (for Raspberry Pi), including Pi Zero Firmware is preloaded and can be easily updated via software Frequency range: UHF: 430-450 MHz, 433 MHz and 900 MHz VHF: 144 MHz, 220 MHz operating frequencies Architecture The top SMA interface is the TX (transmit) port. The bottom SMA interface is the RX (receive) antenna port. Support UHF + VHF bands SMA antenna interface (antenna included) Modem selection: STM32_HS_GPIO Core advantages ✅ Supports independent dual timing of UHF and VHF bands ✅ Signals can be sent and received simultaneously in full-duplex mode Supports mobile power supply, worry-free outdoor operation Flagship technical Independent 2U+2V antenna interface (a total of 4 SMA ports) to ensure zero signal interference ✨ Dual-screen compatible design Adaptable to 0.96-inch OLED screen and Nextion LCD screen Dual-color indicator light displays the working status in real time Application scenarios Applicable to: DMR/C4FM/D-STAR and other digital intercom systems Mobile emergency communication base station Cross-band repeater station integration solution Color: As Shown Material: PCB Pa