cyamamot@girtab.usc.edu (Cliff Yamamoto) (11/19/89)
In article <660@hq.af.mil> illgen@hq.af.mil (Kenneth..Illgen) writes: > For the sake of your CATV company, I hope they gave you the wrong info. >If the same problem exists for everyone on the system then the CATV people >either need to move their antenna location or take a good look at their cable >plant. Normally ghosts that appear to the left of your picture indicate strong >reception of an off-the-air station at the same frequency. Ghosts to the right >indicate multiple paths to the receiving antenna and an impedance mismatch >on the cable plant. Either case should be fixable by your CATV company. My friend doesn't have this problem (we share the same cable system) so I know it's not coming from the cable company's main distribution center. I've got a herringbone pattern running across my pictures. It's diagonal running left to right, about 30-40 lines on the screen at one time. It appears on several channels with the same intensity. It doesn't skip every other channel, it just appears on random channels (from channel 2 to 44). The pattern is not modulated, it's a clean straight unwavering pattern. Does anyone know what causes this? I've heard it's causes by strong FM broadcasts. Well our cable company DOES simulcast it's movie channels in the FM band on the cable so you can hook up your FM receiver. But like I said, my friend doesn't see this pattern at his house. Also this pattern is on both sets in our house, so it's not limited to one TV set. And no, I don't have a FM receiver hooked up, so there is no local oscillator causing the problem. Should I buy a FM trap? It appears on the low and hi cable channels, so I'm not so sure if it's FM interference. Can FM broadcasts hetrodyne with all cable frequencies to produce the exact same herringbone pattern (the width of the lines doesn't change with channel). Any advice on this matter would be appreciated. Cliff
bph@buengc.BU.EDU (Blair P. Houghton) (11/21/89)
In article <6578@merlin.usc.edu> cyamamot@girtab.usc.edu (Cliff Yamamoto) writes: > >I've got a herringbone pattern running across my pictures. It's diagonal >running left to right, about 30-40 lines on the screen at one time. It appears >on several channels with the same intensity. It doesn't skip every other >channel, it just appears on random channels (from channel 2 to 44). The >pattern is not modulated, it's a clean straight unwavering pattern. Turn off your modem. --Blair "Fixes mine every time."