Hi. I’m using a cheap chinese RTL-SDR receiver with a LNA & SAW filter (attached at the receiver end) and the standard indoor whip antenna mounted outside on the roof and extended the cable with a 5m RG174 pigtail. I’m planning on replacing the standard whip antenna with a cheap PCB antenna and also replacing the cable with some RG6 (LMR400 seems way to expensive). Will I see major improvements from the setup change?
Nearest airport (second busiest in Romania) is 3 NM away.
RG6 has the wrong impedance for your receiver.
RG6 is 75 Ohm and the reciever needs 50 Ohm cable.
I would look at an alternative for the cable, maybe LMR240 would suit you fine.
When replacing the cable with RG6 I doubt that you will see any improvement at all since the cable itself is not that suited for ADS-B reception.
In order to determine if the antenna is improving your setup we need to know what antenna you are intending to use ?
Antenna intended: https://www.aliexpress.com/item/1005005800147842.html?spm=a2g0o.order_list.order_list_main.55.21ef1802pHiA9a
Current range and maximum range acording to HeyWhatsThat:
The antenna is not suitable for outdoor use.
It only has an average of 3 dB amplification so don’t expect big steps in the improvement of your reception.
Maybe have a look at www.vinnant.sk they sell adsb antennas for outdoor use for a decent price and realistic shipping costs
it would be sealead in a pvc pipe
also, would I see any improvement if I move the LNA on the antenna end with the current setup?
I’m in the Atlanta,GA area and my PiAware coverage is 85%+ of the Southeast US. I generally track 4K+ flights daily and average around 1M positions. My long-range tracking is horizon-limited at 250-275 miles, as my antenna is about 825’ ASL.
All that to say, I can tell you from experience that RG6 is great for receiver use. I’ve used Belden 1694A RG6 in my PiAware installation for over 3 years. 1694A is widely used for HDTV production installations and has very low attenuation at high frequencies such as 1099 MHz where ADS-B lives.
For transmitters, lower cable impedance matters because of power handling considerations. For receivers, it’s not as important. What matters most for receivers is low-loss cable (lowest attenuation) and the shortest possible cable paths from antenna to receiver. Low-loss cable + short cable lengths = highest signal to the receiver.
This is a great video explaining the effect of cable impedance in transmit / receive applications. https://youtu.be/I-OnQZJv35I?t=812. (The rest of the video is super-technical, but if you are willing to invest the time, it’s very interesting.)
This is a point to some very nice KMR400 coax that is already terminated as you need it and is available in many different lengths to suit your installation. The quality is excellent, and the price is very reasonable for 400. I use it in my system! Available on Amazon.
I’ll second the use of KMR400 in place of LMR400. It’s a substitute and should gain 85-95% of what LMR400 will get you, depending on a number of factors, and it’s a lot less expensive. I’m using it now on my setup.
I’d suggest to roll your own antenna: Three Easy DIY Antennas for Beginners
Scroll to the Easy Antenna #1 Spider. I made one of these that rivals the FlightAware antenna. I ran mine on RG6 for some time but then switched to LMR-400. Def better but I had the cable in hand. I do use the KMR-400 cable mentioned above in a scanner installation and it’s excellent and affordable(ish).
I run a FlightFeeder orange, FA antenna, dark blue barrel filter, fed with 10 meters LMR-240 as supplied by FlightAware. I also built a PiAware with a 4B, prostick, FA antenna and, while waiting for 35 feet of LMR-400 to come in temporarily installed a 50 foot run of cheap RG6 from a box store along with the requisite N/F and F/SMA adaptors. Both antennas are 15 feet AGL and separated by about 15 feet along an E - W axis.
They both pick up the same number of aircraft yet the PiAware consistently receives about 15% more positions than the FlightFeeder. I haven’t yet swapped feedlines between the two receivers nor installed the LMR-400. Those are experiments awaiting better weather but am satisfied RG6 does a good job in this application.
This topic was automatically closed 365 days after the last reply. New replies are no longer allowed.
