Saturday, 4 July 2015

Midland G9 PMR446 5 Watt Full Power Export Modification

In this article i will detail how to convert a normal Midland G9 Plus or G9E Plus 2-way radio to the export version that has enhanced 5 watt output. It also allows the two PTT buttons to be used to operate the radio in standard 500mW and in 5000mW.

The modification is quite simple on this 2015 version Midland G9E Plus.

Take your Midland G9 and remove the belt clip and batteries. You will find four screws located in the battery area and one next to the belt clip. Carefully remove these with Philips screwdriver.

Open the cover carefully, note the wires to the vibration motor, these can easily be broken if they are pulled hard.

At the top of the PCB next to the On/Off/Volume control you will find three jumper links labelled J-1, J-2 & J-3.

To make the modification, simply cut links J-2 & J-3. 

The radio can be re-assembled. When you next turn on the power the settings will reset to factory default.

The radio will operate as it did before but with the exception that the PTT & PTT Boost will work differently. In the menu if you change PRL setting to be 'L'. This will make the PTT button transmit at 500mW and the PTT Boost button will transmit at 5000mW.

Other Notes:

The radio seems to be operated by a Beken BK4811 transceiver IC.

Power consumption measurements at 5.00v
Idle: 78mA
Idle + Backlight: 95mA
TX 100mW: 170mA
TX 500mW: 470mA
TX 5000mW: 980mA

I also made some measurements of the battery level indicator:
Full battery indication at 4.77v+
2 bar battery indication at 4.72v
1 bar battery indication at 4.5v
Bat Lo warning at 4.3v