Dynex™ - 6' Male-to-Male 4-Conductor (TRRS) 3.5mm Cable - Black
Only @ Best BuyThis Dynex™ male-to-male cable makes it easy to connect a variety of 4-conductor (TRRS) devices, including headphones, microphones and A/V accessories, with a 3.5mm interface. The 6' length offers an extended reach.
Connect up to 4 devices to the coaxial connection from your cable or indoor/outdoor VHF/UHF/FM antenna with this mini drop amplifier. It works with the DC power provided by components, or with the AC power provided by the included adapter.
I have a indoor HD antenna with a built in amplifier. I get lousy reception, and wonder if this would help, or if I need to buy a outdoor antenna
Hard to tell without being there, but if you're getting bad reception with an amplified HD indoor antenna, an outdoor one may be your best bet. (I'm assuming you've tried moving and turning the indoor antenna to find the best arrangement.)