Occasionally, during band scans, I'll have a weak signal show up on 153.740. This appears to be ducting of a signal from somewhere (perhaps western Washington, area area from which I also receive ducting of signals on typical fire frequencies such as 154.010, 154.430, etc. The weak signal on 153.740 appears to be a fire or EMS dispatch operation as I'll hear tones followed by a warbler. Looking at the RR database, I see Polk County Oregon is licensed for this but it doesn't appear to be used for dispatch so must be someone else. There are a few Washington licenses on it. Anyone else hearing this? I first noticed it during the summer and managed to detect a 110.9 PL being used. With some downtime during the holidays allowing more listening time and more band scanning for activity, I've noticed it again occasionally the past couple of days. Anyone have an idea where it originates?