Help me with RF interference

[Zenith26kc20]

QRM = NOISE!
The owner of the business next to mine has a laptop that drives the analog TVs nuts with that kind of interference. I can tell when he turns it in and when he turns it off!
Also, check your focus divider for a small crack in it's housing. This will allow a slight discharge which can cause that kind of interference.
If the focus pin is green (corrosion) on the CRT it could be leakage on the socket. Usually this causes focus troubles too.