I am having difficulty with my cable provider (comcast). Through the
cable box, a number of channels exhibit tiling, audio dropouts, or are
completely black. When I view these same channels directly on my
television (to the limit of its 99 channel tuner) they come in, albeit a
bit fuzzy. In addition to this, my internet speed rarely approaches the
paid for 8 meg, typically it's 5 meg or less. I'm wondering if this is
a signal level issue. I have a 60 mhz oscilloscope. Can I use this to
directly measure the signal at the cable outlet, and if so, what levels
should I see? Comcast has been less than stellar in its response to
these troubles, maybe if I can measure the signal levels I can at least
determine if the problem is a low signal to the house, or originates in
the distribution (cables, splitters, associated connections) internal to
the house.

TIA

Dan