FlightAware Discussions

Dongle to roof Antenna confusion about connecters

Hello all!

I am asking for help because the world of antenna’s connection has overcome me…

I have a jetvision R820T2 dongle connected to a raspberry zero. It has been working perfectly during a while but recently I moved to a new hose that has a antenna on the roof just in front of my bedroom.

I have been thinking about use this antenna as a booster for my flightaware machine. In order to do that I want connect the dongle to the wall port and use the connection that is going to the antenna outdoor.

What should I do? Could I use the old antenna as well or I can just use the connection and fit a new antenna outside? Which kind of adaptors do I need to attach my receptor to the wall?

Thanks for your help !

Neither the connector nor the cable are suitable for 1090 MHz.
The antenna is most likely for TV which is a whole other frequency.

An antenna “in front of” the house does not have a view in all directions, you want one at the highest point of the roof.

I’d recommend installing the RPi in the attic and using not more than 5m of good quality coax cable. (LMR200 or CFD200 or something like that)

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Thank you for the reply! So there is no way to “recycle” this old wall connection or the old tv antenna. isn’t it?

I wouldn’t recommend it.
You can of course try and see what the signals are like.

But TV antennas receive horizontally polarized signals from one direction if i’m not mistaken.
So the polarization and frequency is wrong, the coax most likely very lossy, so i doubt you will receive anything.

Theoretically you could get an antenna and an LNA and install it on the roof where the old antenna is.
(Cheap antenna: https://www.ebay.de/itm/1pcs-ADS-B-PCB-Antenna-1090MHz-Antenna-SMA-female-Antenne-CASE/253915016420
FA antenna is of course better.
LNA: https://rtl-sdr.com/new-product-rtl-sdr-blog-1090-mhz-ads-b-lna/ )

With an LNA the loss in the coax won’t be as much of a problem, but you’ll still need to fit F-connectors to it and then have an adapter to SMA or whatever your dongle has.
(There are F-connectors available that can be pushed/twisted onto coax, but i’m not really experienced with that)
The LNA would need to be on the roof and needs to be in a watertight enclosure.
(Wrapping it in selffusing tape and giving it a little roof against the sun should be sufficient, never tried it though)
The LNA will also need a bias-t to supply it with power, i would recommend just getting the rtl-sdr v3 stick from the same website where the LNA is available.

You would also have to make sure there is no splitter or some other gear between the outlet and antenna.

Without an LNA i wouldn’t even try to use the existing coax.

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Looks like you are ‘hosed up’.:sweat_smile:

That’s an European TV (PAL) connection. That antenna, likely for TV reception, will do nothing for your ADS-B reception. At most, the cable going up there, if suitable, may be re-used. An adapter for the connector will be needed as well. Then an antenna designed/tuned for 1090 MHz.

It should not cost you much to do a proper ADS-B antenna installation from the ‘ground up’. Actually, the biggest PITA is the antenna mounting, if in the clear, re-use the existing mounting hardware (mast/bracket). The results will be worth it.

Then follow the other suggestions, things like LNA, dongles, etc.

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Ok, so I guess that before waste all this money I must check if the coax is OK, because looks a bit old… Anyway I would like to use at least the antenna’s structure because rightnow my signal it is really bad looking to West ( you can see picture of my Antenna and coverture area) so I am looking they way to improve it !

Well running a proper coax then wouldn’t be too hard.
You could do that in the first place.

Or just try placing the antenna and RPi in the attic and see how that goes.

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hahaha Yes I am :stuck_out_tongue:
Thank you all! this world of antennas is pretty new to me. I would like to try use the antenna’s support and check if the coax cable is still OK as well. Anyway this old antenna is not in use.

Right now I have my small antena atach to the window, but I have said before…My signal is almost zero to the West photo_2019-06-03_20-55-04

The antenna needs to point straight up, otherwise the polarization is wrong.

Also see this thread:

You don’t seem willing to spend the money for an antenna on the roof, that’s fine, so i’d recommend placing the antenna and RPi in the attic, might have better view in multiple directions.

Unless you have a metal roof?
Then going on the roof or getting the signal through the window are your only options.

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Actually I am living in the top floor (attic-ish) :grinning:

Ouch! I did not know about the polarization. I set it like that because the structure is metallic and the antenna is magneticed.

I am going to change it and read the topic. Thank you a lot for the time and advice

Yeah that gives even more problems.

Try putting it on the lamp and placing the lamp directly under the middle of the window.

1090 MHz isn’t good at going through walls.

But it won’t go through metal at all, like pretty much any electromagnetic waves.

Done! I will check tomorrow to see the differences.

weidehopf, this was a great suggestion (putting antenna on lamp). i sure hope it works for ravenneo because i looks very cool.

Won’t work well like that.

Needs to be much higher up, directly at the glass.

he can hang from a string and use one of abcd567’s extra cookie tin lids as ground plane

What kind of light bulb is in there? Anything other than the old, and mostly banned, incandescent type may genererate a LOT of noise. Try with the light off as well.

Should be well shielded at least from the antenna :slight_smile:

Looks like a bit improvement… i will try some of your advices