Must the cable between the power-insterter and pre-amp be one continous run wihtout any spliters or connectors?

If I have a run of 300 feet of RG6 - made up of 3 100 feet cables - could I put power injectors at each of the 100 foot intervals in this run?

Example:
Pre-amp at antenna > 100 feet of RG6 > Power injector >100 feet of RG6 > Power injector > 100 feet RG6 > Power injector > Split to connect to TVs

Thanks for your thoughts!

There are two issues here, voltage loss AND RF signal loss.

If I read you right, you can only use one power inserter per pre-amp. the closest location to the amp itself, your example 100 ft from amp. You must also limit the splitting and couplers, adds resistance and rf loss.

But your rf loss over 300 ft is a lot and splitting further at the end without amps is ????

This is not easily done with long cable runs, since the UHF freq. is broad and loss varies over it. A major rf slope will occur and special amps are needed to correct this. If you try to play with this, best suggestion I have is a good rf pre-amp at the antenna and power inserter closest to it THEN a distribution splitter amp with adjustable gain to split to TV's.

You are entering area of cable distribution design!

My brother-in-laws setup deep in the country uses about 200 feet of RG-6. There is 1 barrel coupler connecting the 1st 100' to the 2nd 100'. We use the one power injector that came with the CM7777 and it is inside the trailer right next to the TV. It works well. Suggest sticking with the injector that came with your preamp, no need to use additional power injectors.

Right.
There are two issues. 1. The preamp needs power to work, the power injector supplies that, and cable resistance might reduce the delivered power enough to cause the amp not to work. 2. The amplified signal is reduced by going through the cable, the longer the more loss, and there's always more loss at higher frequencies than at lower frequencies.

If you can put the power injector 100 feet from the antenna, any others further away will not do anything at all to help.

However, there's reality -- maybe it doesn't matter. Being the lazy type I am, I'd first try it 300 feet from the antenna to see if that works. Next, can you put it real near the antenna, say in the last 30 feet? I don't know the details of your setup so I can't do but ask.

The signals themselves are another matter. There are two reasons for an amp -- to amplify signals that just aren't strong enough from the antenna, and to amplify signals that the cable attenuates. A seat-of-the-pants approach, where you just amplify the whole mess and feed it through a cable, usually works. This is indeed the realm of signal distribution design, but it might just work by slapping it together. Give it a try. Come back here and tell us if some channels are iffy, if it worked great, if it totally sucked, whatever.