Hi, first, sorry from my english, i’m buyed a gm862 GSM module, this work fine with evboard, I can use all module, but when I plug a antenna and I inset PIN code the device power off suddenly and close comunication.
Im using RS-232 evboard, mmcx to sma pigtail, and quad-band cellular antenna, all from sparkfun
The problem is probably your power supply. When the radio ‘talks’ to the cell tower it draws a lot of power in short bursts (up to 2 amps). If your powers supply cannot provide this current you will get spikes on the power line and the radio will reset. This is a very common problem with all GSM radio modules.