I have dump1090 setup doing ADS-B decoding on a Raspberry Pi using a nice PCB 1090MHz dipole.  It enables me to see a ton of plane traffic overhead.  It serves no real purpose other than it’s something neat to look at.  From my research I felt I should be picking up a much wider view of the sky than I was, and sought out ways to improve.  The antenna certainly seemed good enough.  That’s when I saw the LNA add-on available from rtl-sdr.com.  The difference is startling, honestly.  See for yourself. Read more “RTL-SDR Blog’s ADS-B LNA”

DIY Planar Disk Antenna

I finished up a quick pizza pan Planar Disk antenna based on WA5VJB’s guide. My dollar-store didn’t have anything larger than 13″ pans.  So, with a Planar Disk that should give me a bottom range of about 227MHz, I was hoping.   After getting great performance out of the PD at 70cm, I decided to do a heatmap at 2m to see if it could do anything there.  I compared it with my N9TAX Slim Jim dual-band.  Below is an image comparison slider of the two heatmaps, one from each atenna.  The image on the left is the pizza pan based Planar Disk antenna I made for $2 and a scrap RP-SMA cable from a really low-quality cellphone antenna base that broke.  Standalone images here and here.  I’ll have to find something to compare it to, on the high end, to see how high it can go.  If 1/16th inch separation gets you 1.3GHz, I should be higher than that ’cause it’s probably 1/32″ of a gap at the moment. UPDATE: Warning, images are large.  Second this is how to do the heatmaps here. Read more “DIY Planar Disk Antenna”