I have installed a couple hundred inline amps and have never had any trouble with any of them. Not even the $6 ones. But I know where and when to install them.
The signal strength % numbers displayed by the receiver in test mode are not indicators of signal strength. They are a measure of signal quality derived largely from the amount of bit error correction taking place. If the signal is within the input window of the receiver and it is then amplified, the signal strength will increase but the receiver's signal strength % number will not go up and sometimes it will go down.
You should never put an inexpensive inline amp at the LNB because it will almost always be overloaded. Surely, the cascade that birddoggy described developed excessive intermodulation distortion and made the signals qualitatively worse. If you face the situation of not being able to insert an inline amplifier in, say, a buried or encased coax of 300 feet, you might consider putting a low gain, high input inline amp at the LNB. Spaun makes a 10dB gain inline amp that can handle the power developed when it is installed at the LNB, but it sells for about $70.
Here is the simple arithmetic. An LNB puts pout a signal level of around -30dBm. The receiver's optimally receive input signals of -30dBm to -60dBm. RG-6 loses no more than 10 dB per hundred feet through RG-6, so you don;t approach the input floor of the receiver until the signal has gone through at least 300 feet of RG-6. I tested some at nearly 400 feet with DISHPro singles and 301/311 receivers and they worked without inline amplification.
The original poster should just install the system without the inline amps and see how it works. If he is then dissatisfied with its performance and eliminates all other possible sources of signal degradation, he can install a cheap inline signal amp AT THE RECEIVER end of the coax. That is the opposite of what you'd do to sustain analog RF TV signals. You can do this with digital signals because they don't need as high of a signal to noise ratio as analog signals. Only if that fails should he consider putting an expensive, high input inline amp at the LNB.
The reason I was trying to avoid it is because my contract has long since expired and I hate contracts. I'll check out their current deals though and see what they've got going.
