I need to build a setup where I can only have one cable down from the roof. Since the access is very difficult, I want to keep the minimal electronics there and bring the raw RF signals down where I can split and use howhever I want.
My idea is to inject DC to the coaxial cable and power amplifiers and filters on the roof as per this diagram.
Question is: what’s the best way to combine the signals? I only found TV splitters around, nothing for 50ohms/SMA connectors. Considering I’ll use a LNA before the combiner, would be such mismatch loss noticeable? Any hint to build a combiner/DC splitter myself?