FlightAware Discussions

Results from FlightAware 1090 MHz ADS-B Antenna - 26 in

I had high hopes of getting better reception by purchasing the FlightAware 1090 MHz ADS-B Antenna - 66 cm / 26 in. I had read about “Your cable matters” over and over again on here so I decided to purchase a Proxicast 10 ft Low-Loss Coax Extension Cable (50 Ohm) - SMA Male to N Male at the same time. Install them together.

Previously, I had made a simple, cheap and dirty Spider antenna and had adapted a coaxial cable to it and used an adapter to get the coaxial cable to fit to the Flightaware Dongle.

Results are what I would consider to be roughly 3 - 5% lower with the new antenna.

Not the end of the world but at the same time not an improvement at all.

Setup: Externally mounted Antenna and Raspberry Pi with as noted above a 10’ cable to connect the Flightaware antenna to the Blue Fightaware Dongle.

Installed height is roughly 20’ AGL and probably 23’ ASL.

No obstructions to the view of the antenna, nor was there any changes to the installation location vs the homemade Spider.

You need an external filter. The builtin filter of prostickplus is not sufficient in locations with strong Cell / Mobile signal.

Before taking any further action, first conduct an RF scan to determine what interference your FA antenna is receiving. Please note that FA antenna, being much more sensetive than the Spider, picks Cell / Mobile signals more strongly than the Spider picks these.

Guide to conduct RF Scan is here:

Do I Need A Filter?

 

GSM850-GSM900-Table

My first question would be how are those figures derived? Comparing yesterday’s traffic with today’s? A couple hours vs the next couple hours, etc.? Before jumping on the you need more gear bandwagon, it would be good to know how the difference is being based. Poor results are often derived from poor comparisons.

Yes, you are right. A proper comparison is side-by-side, i.e. simultaneous in time, with both antennas placed at same height, and same location, about one wavelength (30 cm) apart horizontally.

Later addition:
Of course two dongles and two Pi’s are required for side-by-side concurrent in time comparison. A very recent example of side-by-side test is here

What about the gain? If the dongle was already swamped, the FA antenna will make things worse. Try different gain settings, followed by the applicable FA filter (dark or light blue) if needed.

I measured over a period of 2 weeks the daily results. Once I installed the new FA antenna results were noticeably less.

@moone

Did you run the RF scan with FA antenna?

So I need to source a GSM-850 Filter.

Sorry but I do not understand how to perform an RF Scan… That needs to be broken down to a very basic explanation as I don’t know what a DVB-T is.

No, I will be at my home next weekend at the soonest.

I have a FA filter that I had purchased when I was using the FA Orange Dongle.

Will this work? I believe it is a ADS-B Dual 978 MHz + 1090 MHz Band-Pass SMA Filter

DVB-T is the original dongle used for ADS-B. Later Flightaware added a LNA to DVB-T and named it ProStick (orange). Next Flightaware added a LNA+Filter to DVB-T and named it ProStick Plus (blue). Still later Radarbox24 added a LNA+Filter to DVB-T, and named it Flightstick (green).

For the purpose of conducting RF Scan:

DVB-T = FA ProStick = FA ProStick Plus = Radarbox Flightstick :slight_smile:

Without a watermark, (IE knowing for sure if there was more local air traffic vs the previous couple weeks), you can toss your result. Now I’m seeing the 3-5% difference turn into noticeably less - it’s going to be one or the other because 3-5% in this world is nothing - 5% would be 50K positions on a 1M position day and you can get that by parking your car in a different spot (probably not really, but more of less for making the point).

As @Dxista mentioned, maybe drop gain and see if that helps, if not, toss that filter inline and experiment. Higher gain antenna in an otherwise identical setup will more than likely require a gain adjustment to go along with to eliminate overload.

An easy way to understand overload/saturation/interference is to crank your stereo up as high as you can stand it…now try to pick out certain sounds in a clear manner. Now how does it work when you lower the volume? Same deal…

Regarding RF Scan, here are a few how-to’s posted by @abcd567 which should get you sorted on that end: Do I Need A Filter?

Simple 3 step solution:

  • Lower gain: -10 >> 49 >> 45 >> 40 >> 35 and observe at each gain setting.

  • Conduct RF Scan to asses interference

  • Add a filter, light or dark blue, based on results of RF Scan

Is it really a “very basic explanation” to throw a pile of acronyms at a new user??? It’s perfectly clear that you are smarter than everyone else. Do you need to rub our faces in it?

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You have posted a reply using word “rub our faces” to my post which was not intended for you or anyone else, but was reply to OP. On top of this, your reply is very impolite and agressive.

Dont forget members here are trying to help as community, but you have responded as if you have paid a fee and did not get proper service.

If you are not satisfied with my reply (which was not meant for you in any case), please search Google with key words “what is DVB-T”.

No - no it’s not.

DVB-T stands for Digital Video Broadcast - Terrestrial.
(For comparison, DVB-S is the satellite equivalent)
DVB-T is the digital TV standard used in most of the world (some backward countries excepted!!)
DVB-T is not some specific piece of hardware.

It just happens, that the way some DVB-T tuners were designed, they can be used as a far more flexible radio receiver than ever intended.

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Good one!
   

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How I agree with this. Same with DAB. Canada ‘failed’ on both counts.

That said, let’s not nit-pick. The long term consequences of it, if it becomes common practice, is not good for the ‘health’ of the forum.

New users need to put some effort into a new hobby. Ask as many questions and clarifications as you need, but do some research on your own as well.

Remember, one is more likely to attract bees with sugar than with vinegar.

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The OP’s question, and my answer both were specific to RF Scan situation.

When the OP went to the RF Scan thread “Do I need a filter” he found a term DVB-T which he did not know. However he has mentioned in his first post that he is using Blue Flightaware dongle

Not knowing what is meant by term DVB-T in the " Do I Need A Filter" howto, he could not conduct the RF Scan. That is when he asked the explanation.

The first paragraph of my answer gave the history, while last two lines gave the simple answer.

The history part explained that DVB-T is the original dongle from which Flightaware ProStic and ProStic Plus have evolved by addition of LNA (rf amplifier) and Filter.

The simple explanation was at the end and specific to the RF Scan

Please see below the last two sentences of my reply to OP.

Please read my answer in context in which OP has asked the question.

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Getting more confused…

So my current FA Blue Dongle is a DVT?

Ok, it’s currently plugged into my Raspberry Pi. I just need to access it (be on the same network) and type in the code on the thread…

What is confusing me more so is the “Lower the gain” comment. Where and how is this done/performed? Got to admit that that’s not something that I know how to do either

Thanks!

Don’t worry about that anymore, just remember that if you see mention of dongle, stick, DVB-T in the FlightAware ADS-B reception context, we are more than likely talking about an FA Blue/Orange and other SDRs (what about that to confuse you even more - just kidding). SDR stands for Software Defined Radio. The FA Blue stick/dongle is an SDR, all the other Dxx acronyms are functions/uses for such SDR dongles/sticks.

As for the gain, you need to SSH into the RPi to change it, if it’s already operational. Do you have a client, like Putty, installed on your computer? Or edit the Piaware configuration file on the microSD card, using a text editor, if not deployed yet. I’m a Windows user, so unable to help with Mac or Linux.

Nobody beats @abcd567 as an instructor. He has lots of How-To’s ready, and will likely come to the rescue soon.