Radio system

Technical and RF Hardware Information for MB7VV Digipeater.

MB7VV is the Bristol 70cms Repeater Groups Automatic Packet Reporting System repeater on 144.800MHz (2 meters). Yes, we know we are the Bristol 70cms Repeater group, and 2m is not 70cms this is why the repeater has been privately funded by G7FBD and is "Squating" at the Lansdown site.

 

The repeater consists of 3 main parts:-

 

The Power Supply: Tait T800 switchmode PSU rated at 13.8V, 15A

Radio Transceiver: Motorola GM360

Logic: Microsat WX3IN1 modem.

 

Techinical Specifications:-

 

Forward Power from radio: 4.75dBw

Deviation: 2.5KHz

Emission code: 8K00G2DCN

 

The radio system also has two 600R line matching transformers to isolate the audio path between the radio and the logic.

 

MB7VV uses a narrow bandwidth of 12.5KHz on transmit, BUT receives at 25KHz bandwidth to compensate for radio traffic in-correctly using 25KHz when they should be only using 12.5KHz, but who checks!?

 

Motorola GM360 Tranceiver.

Tait T800 mk I PSU

All content is Copyright of The Bristol 70cms Repeater Group