said by Zenit_IIfx:ts not too difficult to do for a plant maintenance tech...just involves some number crunching which can be done with a Computer, and actually moving around a bit to the amplifiers/line extenders and adjusting the gain.
It's actually more complicated then that.
Amplifiers have a set gain level the distribution plant is designed around. Amps can be padded down from that max gain, but not really turned up. Underdrive the amp too much and you cause low carrier to noise problems. Overdrive the amp too much and you cause distortion problems.
If the amp gain is padded down (say to allow future expansion), more amps have to be installed to make up for the shorter feeder runs that derated amp allows. More amps, mean more power supplies, and both mean more money for initial build and maintenance after. A decent distribution design has all amps (of same model) outputs set to the same level. The length of feeder runs and number of ports on each tap is engineered based on that amp gain. The losses caused by feeder and taps it serves are calculated and built to give the next amp the same input levels as the amp before or last tap proper levels. Padding is done on the input of the amp to compensate for differences in feeder runs (i.e. 10 db amp input, 35 db gain, 32 db feeder loss, 3db next amp input pad vs. 10 db amp input, 35 db gain, 34 db feeder loss, 1db next amp input pad). Basically all the feeder runs are made to have very similar losses and input padding kept to a minimum.
Installing a tap with more ports, increases through signal loss, and reduces the signal passed down the line. The closer to the end of line the tap is, the bigger the loss in signal adding more ports causes. Changing a tap to more ports, often means changing all the taps downstream in that feeder run to compensate, hopefully with enough signal left for the last tap or input to the next amp.
Many systems I've seen need another amp installed or an existing amp moved because there isn't enough signal left for good performance at the end of line due to tap changes further upstream. The taps were changed by lazy techs just trying to complete a job with out figuring out what happened or what they're really causing by changing the tap. Often those "need more ports" tap requests are because the drop is connected to a tap it wasn't designed to be attached to. It's supposed to go to another tap.
Adding an amp to fix the end line levels means redistribution of power on the system... another exercise in voltage drop and amp draw calculations needed for proper performance.
All of those changes have to go back to the design department so blueprints can be updated. If not, there is a good chance the next tech out notices the change and puts it back to the old design prints he has.
Long story short, changing taps to a model with more ports isn't often a quick and easy thing done same day. It may take days and weeks for a proper redesign and build change if it's economically feasible. Trying to turn up a single amp in the distribution system to make up for higher losses after it, if it's even possible, is just bad engineering and causes all sorts of maintenance headaches.
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