So I'm using an indoor antenna with my 536. I have my older 996XT I decided to use just for aircraft. Do I really need a powered multicoupler, or is the passive OK. Only doing two radios. TIA!
A passive splitter (combiner) is fine provided the signals you are trying to receive are moderate to strong. If the signals you are trying to hear are already very weak, then a passive split would only make the signal that much weaker. I would try a passive one first and see what you think.
Technically, it does not make very weak signals weaker than any other signals (dB change is the same). But a combination of the signal level and noise of the receiver make make the signal-to-noise more of a communications problem. But I do agree, if only splitting to two receivers, trying a passive one first is a good recommendation.
Previously I was using one omni directional antenna and one yagi for 700-800MHz for two different scanners. All my antennas are in my home office that has a very high ceiling. I bought a Stridsberg MC202 passive 2-port multicoupler and put both scanners on the one omni and still have full signal bars on both scanners. That got rid of the antenna and some cable clutter.