In article ,
Jeff Liebermann wrote:

It's also a problem in the other direction, which is called ingress.
Nearby transmitters, such as mine, can easily get into the cable
system, and interfere with reception.

Heh. I remember a discussion hereabouts, some years ago... it might
even have been you posting, Jeff?... in which the poster reported
having detected cable-leakage problems in his town, reported them to
the cable company, and was being ignored. He found that even the
cables system's central facility (where the downlinks and primary
head-end amplifiers were) was leaking like a sieve.

He visited the office, asked to speak to the lead engineer, and
explained what he'd found. The engineer poo-pooh'ed and said "No, our
system is tight, we're very careful about that." The OP took out his
2-meter radio, keyed down... and the signal monitors in the next room
went crazy, as the 2-meter signal leaked into the system and saturated
the first-stage amplifiers. Picture quality went to hell all over
town and the phones started ringing...