Anonymous wrote:I’m a physicist with long experience in electronics and optics, and I have solved this problem on two set-top boxes in my house. I removed the coax cable between the wall jack and the set-top box and replaced it with one that was 3” shorter. End of problem. What?? Why should something so silly actually do anything? Well, here’s what I think is going on: The RF radiation that enters that cable can be weakly reflected from its ends. If the wavelength of the particular channel has the correct relationship to the cable length, a resonance can be set up, just like blowing into a flute creates distinct tones. This resonance can cause problems. Changing the length of the cable by a quarter of a wavelength shifts it out of resonance. The channels I had problems with use frequencies 727 MHz and 636 MHz. (You can find this using Menu/Settings/System Information/Info in FiOS). The formula for the wavelength in this kind of coax cable is: wavelength in inches = 7793 / frequency in MHz. This gave 7793/727 = 10.7 inches and 7793/636 =12.3 inches. A quarter of those lengths is 3 to 4 inches. I had a cable lying around that was about the right length – being off by an inch or two wouldn’t matter. I got lucky the first time. If this had not worked, I would have tried some other lengths within a wavelength of the original cable length.
Are you for real? Respect, chum. You're a smart one.