ADTech's conservative advice is also valid. The lower gain preamps, like the CM7778 and the AD Juice, have sufficient gain to cover distribution losses. Once the signals are amplified by the preamp, they are better protected from distribution losses. A 3 dB loss between the antenna and the preamp input can be 10x worse than a 3 dB loss after the preamp. So, keep the coax between the antenna and the preamp input short, because that loss directly subtracts from the antenna gain and increases the System Noise Figure. Here is an example of how much difference the placement of a 3 dB loss can make:
The preamp Noise Figure is important because it primarily determines the System Noise figure because of its location at the head end, according to the Friis Noise Figure equation; the lower the figure, the better able you are to receive weak signals.
https://en.wikipedia.org/wiki/Friis_formulas_for_noise
You can do your own calculations for your system using the Systm Noise Figure Calculator by holl_ands and majortom:
http://imageevent.com/holl_ands/files/ota
http://imageevent.com/holl_ands/file...=0&w=1&s=0&z=4