AntAltMike said:
I doubt that amplification will solve your problem. The 119 signal power levels aren't appreciably weaker than are the 101 levels. You may have a dish aim problem, or a wiring problem, or a partial obstruction, or even an LNB problem.
There will be no operational problem using an inline amplifier that nominally operates on 14 to 18 volts DC. If an LNB sees about 15.5 volts or higher, it sources the evens, and if it sees less than that, it sources the odds. In fact, if you send 18 volts to one side of the LNB and no volts to the other, the 18 volts will drive the LNB's amplifiers and you will get the odds from the port that has no line voltage present.
You can put a 10dB inline amp right near the switch input. You should not put it near the dish. The dish puts out about -30dBm of signal strength. The inline amps are low-powered amps and typically develop unacceptably high 3rd Order Intermodulation Distortion if driven above about -20dBm. The one exception is a very expensive Spaun 10dB inline amp that probably retails for around $70. I have used that at the LNB when my wiring was going to be relatively inaccessible for a few hundred feet, and I didn't want anyone in the future to have to spend hours looking for a the preamp if it ever failed. The 22Khz inputs are for Sat B/C.
How long are your lines? You should be able to safely go over 300 feet in combined dish-to-switch-to-receiver length without inline amplification, and I have never had trouble at less than four hundred feet.
thanks. well, for the record, no, the amps didn't work. i'm at my wit's end here because i don't know what the problem is. i'd say the lines are roughly 100 feet from the roof to the basement, then maybe another 75 feet back up to our apartment. i live in a complex with three identical buildings, each with its own triple LNB dish. a neighbor in another building, who also lives on the fourth floor (same as us), gets his Sat B/C signals with no problem. i checked, and ours is wired the same as his. he's the only other person in the complex with HD through directv.
now, i had a guy from directv come out, and he checked the signal in our apartment, and he said it was low. he said (and i'm just quoting what he said, not really knowing what it means), "it's in the 30s, and it should be in the 50s or 60s." however, i had another guy come out who didn't really seem to know what he was doing, but he bypassed the 5x8 switch in the basement, connecting two of the lines from the dish to the two lines going to my apartment. when he did that, i got my HD channels. however, the rest of the building lost half their channels, so that's not a feasible solution.
i've had two technicians check the dish alignment, and both said that was fine. there are no obstructions. one guy was set to replace the LNBs, but then he thought he fixed the problem when he bypassed the switch. could the switch itself be bad? does that ever happen? if so, what switch would anyone recommend?
edit: for the record, i swapped my lines with another apartment's lines on the output of the 5x8 switch, but it didn't fix it. could the switch's inputs be bad?