Sunday, 3 December 2017

rtl-sdr.com antenna kit: Orientation Matters

A lot. Official recommendation is to install antenna vertical (up-and-down), as a real man, didn't read the manual, then posted results in a recent ADS-B comparison.
Mea culpa, I was wrong, as an eagle-eyed reader pointed out:

"Orienting dipoles goes back to the signal polarization, horizontal vs vertical. It should match otherwise you'll get losses. But the way you've oriented it makes it vertical, but more like a whip. So there should be some improvement by using it in the correct orientation. TV signals are usually strong and so the bunny ears can withstand being in the wrong or random orientations."

Fair enough, so onto ADS-B testing, got an antenna kit from rtl-sdr.com for review and ordered one within minutes as it's well worth the money, then some ended up with two identical kits:


Back end is two ModMy Pi 3 Raspberries, so only variable is antenna used:




Then my jaw dropped, bunny ears configuration results:


Vertical dipole results:



No math required, more than 2x performance. Where's a stone I can hide under?


Polar plots


First of December, 21,033 Totals on vertical orientation, geographical coverage:



Bunny ears with 9,563 Totals on the same day, geographical coverage:



Conclusion


"RTL-SDR Blog Multipurpose Dipole Antenna Kit" works, 144 nm max range in an unamped, stock setup is simply astonishing at my location.
Would, and do recommend to grab as many as you can from the manufacturer, but others have also seen that sliced bread is better than a loaf, therefore it's sold out.





1 comment:

  1. It would be interesting to see the results with both dipoles being oriented vertically, but with one missing its lower leg. Obviously it will perform worse, but by what percentage. Thanks for the great posts.

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