There’s this one channel at the very end of the channel spectrum. It’s a black screen with white graphics of a grid and there’s a spiky line that goes across the middle.
Some of the text that I see is: Ref Level 25.0 dbmV, Atten Auto, Scale ldb
What is this???
My WAG is that it’s a test signal for the line technicians.
They can plug in and determine signal loss/interference at any point in their network.
Damn! What idiot junior technician left that channel open?!
If they know about it, they might figure out how we monitor their thoughts, and implant correct thoughts. Someone will pay for this!
What?
Of couse this is an encrypted line. I’m not fool enough to let the public see this.
We have that on our cable system, too. It appears that, for some reason known best to the cable techs, they have a camera permanently focused on an oscilloscope in their office. Maybe the Chief Engineer uses it to impress guests (“Look, they have this channel just for ME!”) or it allows techies to see how the system is performing from any TV set, anywhere on the cable. I find it handy when I’m having trouble getting to sleep…:o
Let me start by saying that I don’t know what that is. I can say that after being a customer of no fewer than five cable companies in Colorado I have seen that channel only in Fort Collins. AT&T analog and digital did not have it, Optel did not have it, and whatever the cable company in Greeley was did not have it. None of the people that I knew in Fort Collins had any idea what it was either. So basically we are as mystified as you.
My last channel says “All your base belong to us”
It’s not an oscilloscope, but a spectrum analyzer. The difference being that an oscilloscope shows signal level vs. time, the spectrum analyzer shows signal level vs. frequency. I don’t subscribe to cable service, but I’ve seen it at my in-laws’ house, and I recall that it’s not a flat noisy line going across theirs, but has several large, slightly moving humps to it. These are the TV channels that the spectrum analyzer is tuned to.