Hi all! I have a 4ch DVR with 1200tvl analog cameras. The connection is through CAT5 cable with video baluns on both ends. With a short cable i have good image quality, but if i increase the cable length (around 30 meters), the image is flashing all the time, triggering continuously false alarms. I uploaded a sample movie file here: http://www.filedropper.com/daynight Can anyone explain me, what's going on? Thanks a lot!