Hello and welcome to the RadioReference forums. I too have a 436 so I will try to help. First of all, can you paste the system you're talking about from the database here so we know what you're looking at. Second lets make sure you are actually talking about a frequency here and not a talk group. Does your display show anything else besides what you described? Next are you hearing any legible conversation when that occurs? And are you using the sentinel PC software that came with your scanner to program the system's you are trying to listen too? And in the meantime here's a link to Mark's Scanners, a very helpful tool. Easier to Read BCD436/536HP Digital Scanner Manual. This will take you directly to the 436 info page, but there are numerous other scanners listed as well. T.T.Im facing an issue when i hear a certain frequency that is the good one the DAT and LNK blinks and the P25 comes out once for a few and leaves and takes a good while hear the rest. please help see what i can do to fix and see. thanks.