I have nearly exhausted all explanations, and tech support ran out of options long ago, and I can only guess at what is happening here, so I am passing this along as a good brain teaser if nothing else. If anyone knows a solution that would be great as well. We have Direct TV and a two TV system. So, two transducers are at the dish - one for each TV. From there, two separate RG6/U coax cables go off in two different directions. One side makes about a 200 foot run, and the other side makes about a 450 foot run. I think 300 feet was the official maximum that was gauranteed to work. The longer run has an unpowered in-line amp installed about at the midpoint. Here is the problem, at about noon, and between 4 and 5 PM, the long run loses certain channels. The signal strength for those stations is indicated as zero. It is not unusual to lose specific channels due to certain programming issues with the Direct TV box, but this is ruled out. I have tried switching the two boxes and the problems remains with the long run. I have also tried reversing the transduces at the dish - with the rightmost, then leftmost xducer tried for the long run. The problem remained with the run. The fact that we only lose about 10 channels out of maybe 30 or so main stations indicates to me that the TV and the coax is fine. I see no kinks or pinches and it ohms out fine. The line amp is needed in order to get any signal at all. Also, the indicated signal lever drops from about 50% to zero with nothing in between. The DTV people tell me that this is because the indicated signal level is not really a signal level. This really respresents something else; or the tech didn't know. The angles of the sun at these times of day would seem to have no bearing on the situation. Nothing jumps out as a likely angle that would swamp the signal uniquely. Finally, the short run never has this problem. Almost forgot: First, shorting the coax to gnd to discharge any residual static charge does not solve the problem. Tsu has noticed that by constantly jumping to and from a missing station, it can usually lock on the station after several tries. Finally, if I set the TV on the short run to a channel lost by the other TV, the missing channel comes back. So, sympathetic resonance at the transducers appears to be helping to lock the signal on the dropped run. Efforts at blocking the sun seem to make no difference but this does seem to be related to the sun. The problem has persisted for two years but only from about June until Sept or Oct.