Somewhat frequently, for like an hour or so at a time, I am getting some data noise on the LEA channel in my area, 155.790. The data sounds very similar to SCADA telemetry -- you know, like the data that is sent by water well monitors, gas monitoring stations, and the like.
Normally, assuming this is just some sort of DX, I would tone up my LEA channel, and call it good (use CTCSS to eliminate all traffic on the frequency unless it has the appropriate CTCSS tone).
The problem is, the traffic carries the 192.8 Hz tone, which is the same tone as Area 1D LEA. (In my area the closest repeater with that tone is Terril LEA.)
I assumed that some nearby utility department has a transmitter on (Area 1's) LEA input frequency, 154.770 MHz. But I have been unable to confirm that. Also, the data transmissions are very short, so part of me wants to say that they aren't actually going through the repeater, since there's basically NO repeater tail -- that the frequency programmed in the SCADA devices is the OUTPUT LEA frequency, 155.790.
Can anyone shed some light on this? Do any of you have this problem CONSTANTLY rather than occasionally? That might help us track down the location of the SCADA data . . .
Thanks!
Normally, assuming this is just some sort of DX, I would tone up my LEA channel, and call it good (use CTCSS to eliminate all traffic on the frequency unless it has the appropriate CTCSS tone).
The problem is, the traffic carries the 192.8 Hz tone, which is the same tone as Area 1D LEA. (In my area the closest repeater with that tone is Terril LEA.)
I assumed that some nearby utility department has a transmitter on (Area 1's) LEA input frequency, 154.770 MHz. But I have been unable to confirm that. Also, the data transmissions are very short, so part of me wants to say that they aren't actually going through the repeater, since there's basically NO repeater tail -- that the frequency programmed in the SCADA devices is the OUTPUT LEA frequency, 155.790.
Can anyone shed some light on this? Do any of you have this problem CONSTANTLY rather than occasionally? That might help us track down the location of the SCADA data . . .
Thanks!