HELP NEEDED: Coaxial Antenna Cable Conundrum

I am looking for any antenna guru’s to help me with this current conundrum I am having. Currently I have the flightaware 1090 antenna in the perfect spot on the roof. The thick 50 ohm coaxial cable it being fed to the outdoor cable box where all the 75 ohm TV/Internet cables can be tapped into and used on in the house. I have correctly identified which outdoor connection leads to where my Raspberry PI is. My issue is when I spliced the coax cables together to allow for the change in cable size, I seem to have lost a significant amount of capability in picking up aircraft in the area. Anyone have thoughts on how to best approach this? My whole goal is to avoid drilling any holes into my house and tap into the coax infrastructure already in place. If you are a master in this topic, please email me your ideas at This email address is being protected from spambots. You need JavaScript enabled to view it., as I seem to always forget to check back on my posts in forums.

Note: The coax cable that is already leading from outside the house to the inside does not connect, split, or interfere in any way shape or form within the walls/crawlspace.

Note 2: I am aware the long length of the system I am trying to implement is long (approximately 100 feet total, 1/2 is the 50 OHM cable, and the other half is the 75 TV/Internet style cable in the walls) and will reduce the power of the antenna. If you have suggestions on how to boost this as well, that would be much appreciated.

Thank you,
Erik

Hi Erik,

the antenna you are using is passive, right? So you don't have a pre-amp on the antennas end? Rule of thumb here is that a passive antenna is fine for cable lengths shorter than 15m. For anything longer than that, you should install a 1090mhz preamb on the antenna's end of the cable.

Matthias