Control channel 774.634375 sys i.d 1f1 radio displaying that it is a p25 frequency . I thought it might be the new King county transit system . I don't show that frequency for that system and the sys i.d doesn't match.
Is this a mirror image of an existing system ?
Is this possibly the new state DOT system rumored to be in place?
Any information or speculation even would be appreciated.
Steve
If you're getting a decode on it and it's reporting a SysID that isn't already in the DB, then you don't want to completely overlook it. If it's an image, then the frequency isn't correct -- but you have found a new system and it may be of benefit/interest to you to attempt to figure out what system it is.
Is the signal strength strong? If so, then turn on your attenuator and see if you can still pick it up. If you can still pick it up with your attenuator on, I would certainly investigate further the possibility that it is a 700 mhz signal and not some image from somewhere else. No matter how you slice it, that frequency is not absolutely correct, but if it is truly a 700 mhz transmission then the true frequency would be just slightly above or below that frequency.
Now, if the SysID was one that was already known in the DB, then you could easily determine whether it was an image or not. But since the SysID is different, you can't tell for sure.
If you actually get a good decode on it, hook up your computer to it and run Pro96Com. if it's truly a P25 control channel and if you can get any kind of decode on it, you'll be able to know the true frequencies because the control channel will be reporting that information and Pro96Com would pick it up. If it's an image from another band, as long as you can get a good decode on it Pro96Com will reveal the true frequency.
Mike
