I only really just got into ADS-B receiving/ tracking and have been inspired by many of the numerous posts here about reception, filters, antenna construction and testing, etc. There are a lot of very knowledgeable folks who have written very detailed instructions that anyone can follow.
Like many new users, I was in a hurry to get going and so built two antennas; one 1/4 wave spider and one 8 element collinear. I experimented with un-amplified Rg6 coax runs of varying lengths feeding into the FA Pro + dongle into a Raspberry Pi. While I was receiving 30-40 flights with each design ( yay, sparky it works ) and ranges of maybe 90nm, I was thinking my antennas were probably not spot on and I probably simply wasted my time with those efforts and should have just bought the FA antenna and better coax.
I built a second Pi and moved the same collinear to a different location. HUGE and I mean HUGE difference ! Same un-amped coax and using no filter other than the Pro + dongle internal filter I’m seeing 150+ planes out to ~250nm - nearly the same as the HeyWhatsThat website depicts for this low (12ft above sea level) elevation.
The antenna was built from junk Rg6 coax of unknown heritage that was just lying around and may not even be tri-shield. I also apparently watched the wrong how-to video as I used 111mm element lengths and it’s not terminated. I did artistically add a 1/4 wave element to the last element and mount it inside a sealed 3/4" PVC pipe … In other words, this thing probably should not be working at all I was totally ready to pitch it into the trash.
The reason for my post ? For anyone who is starting out and not getting the results you expect, for heavens sake, move your gear and try it at another location as a sanity check. Location, location, location.
What I hoped to be my main FA site is location-challenged and while I’m going to work on improving it, there’s no miracle fix for it.