[haarvi]

I think you are right in your surmise of the problem being connected to the cable
connection.
The hum came back.
I have a headphone amp connected to the same line and was getting a hum
while listening to headphones.
But the hum in the headphones disappeared when I disconnected the cable line
to the cable box.
The cable company will be sending a tech.
But I am afraid he won't be that savvy on what may be involved.
Since the cable company tech guy is likely to be a trained installer rather than
trained in the ins and outs of electronics.
I was told the cable company (Time Warner in New York) has disbanded
their tech department.
Which I would have had more confidence in.
I am imagining that you might be able to help me guide the cable company tech.
Would replacing the cable receiver box be the way to go?
Or is there some kind of add on which could be added to the line going
to the cable box which might eliminate this hum?
A hum which has come, gone, and come back.
Very much appreciate your last response.
Without your pinpointig the cable line as a likely trouble spot, I never would
have gotten to what I am now quite sure is the root of the problem.