Normal
Re: AC and signal cable of whatever typeThe fact that it was cable on the reel is a real issue. Cable wound on a reel forms a transformer. with that much of the cable still on the reel, you probably had a transformer in the neighborhood of 1:100 picking up the disturbance from the wall outlet.With any kind of signal cable, the very worst thing you can do is to have it neatly wound on a drum or coil. A random pile (rats nest) of cable is far better at rejecting induced noise.
Re: AC and signal cable of whatever type
The fact that it was cable on the reel is a real issue. Cable wound on a reel forms a transformer. with that much of the cable still on the reel, you probably had a transformer in the neighborhood of 1:100 picking up the disturbance from the wall outlet.
With any kind of signal cable, the very worst thing you can do is to have it neatly wound on a drum or coil. A random pile (rats nest) of cable is far better at rejecting induced noise.
