MB7PMH uses a GM300 Motorola transceiver connected to a MMVDM board. The GM300 works on the DAPNET frequency (439.9875 MHz), and uses 1200 Baud audio from an MMDVM Duplex board.
• The 19” rack also contains a Raspberry Pi B with Pi-Star, a 12V to 5V converter for the Pi, and an 80mm fan to cool the system.
• There is a 3.2” Nextion display to show the status.
• Connection is via 12V fused at the back of the unit. The GM300 uses a mini UHF connector. This is brought out to an N connector on the back panel.
• Audio levels are adjusted by potentiometers on the MMDVM Board (the RX Squelch is used to check channel occupancy).
Useful references:
