Hi， For question 1: Please following the links http://wush.net/trac/rangepublic/wiki/BuildInstallRun. I do with it step by step, it's OK. For question 2: UmTRX has two channels, so the PCB has TX1 RX1 TX2 RX2 interface. TX1/RX1 for channel1. TX2/RX2 for channel2. So there are 4 cables. GPS antenna is for clock calibrating. Calibrate with GPS: 1. Take your UmTRX outside to get GPS lock. 2. When GPS acquires a lock, use 'umtrx_vcxo.py' utility without parameters to read current VCTCXO DAC value in a loop. 3. When the value stabilise (couple minutes after GPS acquires the lock), write this value to EEPROM: ./usrp_burn_mb_eeprom --key tcxo-dac --val <YOUR_VAL> 4. Now i should pickup the value from EEPROM on boot, so GPS is no required unless you change ambient temperature considerably. Note, that you should warm up your UmTRX for a while before calibration, because it depends on the TCXO temperature. jiangwy From: Manoel Aposaz Date: 2013-09-12 04:55 To: umtrx Subject: how can i scan the frequencies in an area with GNU radio and Umtrx Hi all, If, someone is reading this, please i need help: 1- I want to know if there is a manual showing how to put all the part of the package of Umtrx togheter. 2- If i want to scan the frequencies in an area, what can i install to let GNU radio communicate with Umtrx to show the frequency graph that will help me choose the non used frequencies (it is possible with USRP and i want to know how to do it with Umtrx). 3- My last question is to know if handover is possible with just OpenBTS 2.8 and Umtrx modules or it required an OpenBSC and OsmoBTS architecture. Best regards: Manoel.