5.5dBi 1090/978 N-Type Female Antenna - 26-inch

I have some thoughts on his advice, a someone who has invested quite a bit of time and money into a permanent ADSB feeder. Mounting your antenna on the roof will be the single best improvement you can do for your reception, but if you can't put one on the roof for whatever reason, you could try mounting it outside as high as possible somehow. I think you probably have this antenna. I'm skeptical if what you have is actually properly tuned to 1090 MHz, but you'd need a NanoVNA to find out for sure. If you do ever decide to buy another antenna, buy this ADSBexchange antenna. In my experience, it's almost as good as a DPD Productions ADSB antenna, but at a fraction of the cost. A USB extension cable is a wonderful idea. Your USB ports will benefit greatly in the long term from not having a giant diving board cantilever-ing off them. Besides, with two USB extension cables, you can plug two RTL-SDRs into your front USB ports instead of just one! I'm going to disagree and say that you should go with RG-8X/LMR-240 or similar instead of RG-58 if you're going to buy new coax. It's slightly more expensive, but it's less lossy. If you're serious about putting up a permanent feeder, go with LMR-400 or an equivalent. That said, I agree with the overall sentiment. It looks like your antenna has a built-in RG-174 cable, which iextremely lossy at 1090 MHz. That's another reason why I'd recommend a different antenna. I'm going to emphasize "may or may not" here. I found that putting in a filter+LNA combo unit significantly improved the amount of planes I was receiving. However, this was after I put my antenna on my roof. I don't have any firsthand experience with an indoor antenna with a filter+LNA. You also have the choice buying a filter+LNA for your existing RTL-SDR, or you can buy dongles that already have them built in. I only have experience with filter+LNA units from Nooelec and Uputronics, not the dongles with them built in. Height is might here. You really want this thing as high as you can get it, although I'm not sure if putting it higher above the window would make performance worse or better. Good luck! Let me know if you have any questions. I think you also mentioned wanting to get a new SDR, which I think I can help with. I own an SDRPlay RSP1B, an Airspy Mini, an Airspy R2, an Airspy HF+ Discovery, and a LibreSDR (PlutoSDR clone).