The switch pwictured is not really a multiswitch, but more of a 'dual' diplexer, whereas the low freq is joined with two outs instead of one that would use a single dplxr for this job.
The dual and finally the triple LNFB dishes need a 22 khz pass tone from source to dish to appropriate the right bird for the channel watched. (think of an old c-band and how it actually had to track and move for the next channel-now with no motors this dish doeas this without motors)
Back to your question, an "active" (powered) switch is/was usualy used to only amplify the terrestrial/catv low freq signal to miltiple tv receivers and sets. the rule of thumb being any more that 3 drops will need this boost.
Recently DTV is using active swtchs instead of passive for this event-that-with more than 4 outs and needing 22khz tone gateway, the active swtch will lock polarities with even and odd xponders without the rcvr's output of 13 or 18 volts.
Todays active mltswtchs for the 3 LNB dish do NOT have a low freq in, but are active for said reason.
Theoretically, like some really old RCA recievers used in home and in MDU situations, you can literally block the sat 'in' voltage and still get channels on both right hand and left hand polarity. That was then, and the ol monster pictured was made to be of use before this technology was ever invented. Right dish, wrong era, or something like that. Look at it this way, the pictured item has only 3 inputs, one terrestrial and one 13 and one 18 volt for even and odd xponders, or-in laymans terms "to make the damn thing work".
There is more to the picture than what is seen: with 2 inputs for sat, where are the other 2 drops from the 2 DUAL LNB's? You are probably only getting even xponders one 101 and vice versa on 119.
Right?
Re: Directv 3 LNB feed
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