Motorola GM950 small RS232 Interface

Today I have finished the small RS232 interface to manage the Motorola GM950 UHF/VHF transceiver.
This small interface will cost you about 10 Euro, and will give you much fun !
I had made the PCB layout on the test board, the design is so small that you can easy do this (see picture).

The yellow line’s on the back of the PCB, will show the line cuts needed to place the parts right on the board.
In the green circle you see the small modification on pin 9 and 8 of the 9 PINS RS232 connector.
in the schema you can see that the use of a 9 Volt battery will be oke, but when you make a stable 5 Volt on the PCB the communication will go to be stable to connect to the transceiver.

Back of PCB Motorola

The software you can get from the website in the UK (see ‘Ham links’)

The original design is made by IK5BZH, so that OM must have the credits to find out this small interface !

I have learned that it will be best worked with short RS232 cables and full wired, no crossing cables or what else.
For the connection to the RJ45 (Microphone) connector you have to pay attention, this is 180 degrees rotated – PIN 8 is on the left of the RJ45 !!

Both GM950 ( UHF and VHF) transceivers can be handled with this interface, the best software to use is version r2.00.00.

Motorola PCB 2Motorola PCBSchema RS232 interface Motorola







If you double click on the pictures you can see more !