It's necessary for me to go over 250 ft to get visibility. At that range, even though sats 119 and 110 are locked, I can't receive the higher channels? Is this due to distance, or something else?
What dish are you using? What receiver? Go to menu 6-1-1 and list by transponder and satellite your signal strengths. The higher the signal frequency the more loss there is per foot of cable. but channel numbers do not equal frequencies. What cable are you using for the 250 ft run how many splices do you have? Do you have any barrel connectors with white centers?It's necessary for me to go over 250 ft to get visibility. At that range, even though sats 119 and 110 are locked, I can't receive the higher channels? Is this due to distance, or something else?
Dish Pro uses 19 volts and I believe will work down to 15 volts so the 250 ft with solid copper RG-6 should not cause a problem. Legacy which relies on switching voltages either 12 or 18 would be the worst choice for long runs of cable. Dish Pro uses band stacking instead of voltage switching so it becomes more prone to signal loss because the higher the frequency the faster it is lost over long runs. Dish Pro is also affected by barrel connectors blue are tested to the higher frequencies that DISH uses. White/clear are tested to the minimal cable/OTA frequencies though they may work at higher frequencies. I had a problem trouble shooting one of my own systems that wouldn't work with high frequencies of Dish Pro. After bouncing my head off a brick wall and even calling DISH Tech support I finally found a ground block in the line with an old clear center isolator, yes it was the problem.The distance is more than likely your problem. The reason distance becomes a problem is as the length of the coax increases its resistance increases as well. As the resistance increases voltage drops, and current increases. There for once you get to a certain point where the resistance of the coax is beyond the spec designed into the system the voltage drops to the point where the LNB doesn't function properly, and the receiver can't control it fully. I'm not exactly sure what a receiver looks at during a switch test (other than the obvious), but from past experience a system with excessive cable will usually test good on its switch test, and even download its software. However when changing channels it will either just freeze on the channel, or display the signal loss screen. Removing any barrels will help, as well as stepping up to RG11 coax. also you might try using a legacy LNB.