MB7IVG Equipment

MB7IVG Gateway

MB7IVG is a simplex 2m analogue internet gateway connected to the HUBNet Allstar network. It uses a Raspberry Pi 3B and a modified USB sound card to connect to a Tait 2010 radio. The modified soundcard detects when the radio is receiving a signal and it also actives the radio transmitter. Audio to and from the radio is converted between analogue and digital data by the USB soundcard and fed to and from the RPi.

The gateway contains a second Allstar node. It is connected to an audio amplifier and microphone and can be used as a radioless node on its own or linked to the gateway node. 

Radio

MB7IVG is a Tait 2010 series 2 high band VHF radio model number T2010-321-xxx

The radio has been modified by fitted with 9 way D connectors on the back with connections to the internal options connectors for the required interface signals. A Maxim DS18B20 temperature sensor has been installed inside the radio to monitor internal temperature so a cooling fan can run only when needed.

Gateway Controller

A Raspberry Pi 3 is used to control the gateway nodes and is using the hamvoip V1.5 image.

Remote control features on the Raspberry Pi's allows status checking and monitoring remotely. The radios temperature is monitored using the added internal temperature sensor. The cooling fan is controlled using a script to control a GPIO output on the RPi.

Radio Interface

The interfaces between the radio and the Raspberry Pi controller is a modified CM108 chip based USB sound card. It is modified to provide the PTT switching of the radio and monitoring of the COS output from the radio. The COS signal tells the RPi a signal is being received by the radio with the correct CTCSS tone.

Antenna

 A simple half wave dipole is used for MB7IVG's antenna.