Moshe Braner SoftRF with ADSB

[FrankT]

MB158 with SkyDemon working from the first start with WiFi.

[FrankT]

Case: https://www.thingiverse.com/thing:6986452

Op vrijdag 4 april 2025 om 12:44:22 UTC+2 schreef FrankT:

[FrankT]

[Alan Hall]

Where are people buying the GNS5892R in single or small quantity? I don't suppose there is a UK supplier?

On Friday, 4 April 2025 at 11:48:45 UTC+1 FrankT wrote:

[VirusPilot]

I purchased mine directly from the manufacturer: https://www.gns-electronics.de/product/gns-5892r-low-power-low-cost-ads-b-modul/

[Alan Hall]

Thanks VP, I find the 30 euros postage pretty cheeky to put it mildly but if that's the only way......

[VirusPilot]

They seem to have a booth at AERO next week so I can potentially visit them.

[FrankT]

I purchased mine also directly from the manufacturer. I searched the web but that was the only option. 

The shipping cost for such a small product is ridiculous but I wanted to build one.

It is still cheaper than a new SkyEcho2 :-) 

 

Op vrijdag 4 april 2025 om 17:48:07 UTC+2 schreef VirusPilot:

[Vlad Belayev]

I ordered mine from OzRobotics last week. https://ozrobotics.com/shop/receiver-module-gns5892r-ads-b/
Slightly cheaper on delivery $20, but still. I belive they are US based.

It came quick,  in 2 days. I ordered two and split delivery cost with fellow pilot.

Installed on Monday, works well with TBeam 1.2 and MB155.

Where are you based Alan , UK?   I might know if more people interested in getting the module, as I am doing a club talk, next week. 

Could do a group buy.

Cheers.

[Alan Hall]

Yes I'm in the UK and a group buy would be great.

[Vlad Belayev]

Thanks @FrankT for pictures of your build and the model of the case.

I am also installing GNS5892 receiver into my T-Beam and thought I 'd post pictures of my build.

[FrankT]

Thank you for sharing.

 I'm in the Netherlands and a group buy would be great to have a second unit for experimenting.

Frank

Op zaterdag 5 april 2025 om 21:29:22 UTC+2 schreef Vlad Belayev:

[Gary Jones]

Good afternoon all. Have my ads-b chips on order but wondering what antenna and sma connectors you used in your builds. Many thanks.

[R. van Twisk]

The Antenna is male. So you need to get a FEMALE connector.

I would use the screw on case connector, something like this:

You can get SMA connector with RG178 cable that you can use, something like this:

Just cut of the connector (the right on) and solder on that ADSB module... be carefull though, the modules where not designed for direct soldering, so it's a tad fragile.

If you use RG174, it's nice and flexible for in the case. RG178/RG316 is very stiff although beter quality, with lower loss for in the case it's not nice to work with.

if you build in, you can use RG174 to route in your plane (if you have a glider or experimental). But again, for ADS-B it won't matter much. For FLARM/OGN you properly want to use that cable because the energies are much lower.

Hope that makes sense

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[Moshe Braner]

For adding the ADS-B module to SoftRF I would suggest this kit which includes appropriate cable pigtails:

https://www.amazon.com/Antenna-Connector-Extension-Lora32u4-Development/dp/B0D1C7DM4G

This antenna is supposedly for 915 MHz but works well enough for the purpose.  And the pigtails are thin and flexible.  The idea (same as what RVT wrote) is to cut the pigtail to about half length and strip the leads (inner conductor and outer shield) and solder to the ADS-B module, and mount the SMA jack on top of the T-Beam case.

[Marco Zonca]

A few moths ago I buy a bunch of these small antennas. Today I "sacrificed" one pulling away the rubber black cover, it shows the core wire forming the antenna. I guess it is a 1/4 wave length, resonating at 880Mhz as per Nano VNA test.

At 880Mhz the wave length is 0.3407m, so 1/4 is 0.0852m
At 1080Mhz the wave length is 0.2776m, so 1/4 is 0.0694m

The difference is 15.8mm shorter in favour of a 1080Mhz resonant antenna. To cut the wire is easy, and after putting at his place the rubber black cover I obtained an ADS-B small antenna working at 1080Mhz better than the original that was made for lower frequency.

Honestly I proceeded cutting the wire just a few millimeter at a time, wear the rubber cover, testing with Nano VNA, cutting again... etc. etc. until I reached a good SWR at 1080Mhz. I suggest to do the same instead to cut directly  the theoretics 15.8mm. The rubber cover influences the response as well, so is needed to put it at his place for testing with the instrument.
I stick a white piece of tape to recognise the cut antenna.

A few pictures below:

The original antenna.

The original frequency / SWR response.

The new modified antenna.

The new modified antenna (without rubber cover).

The new frequency / SWR response after cutting the copper wire (should be cut a bit more...)

Does it make sense?

[Moshe Braner]

Thank you Marco.  Yes the antenna can be modified if you want, to be more sensitive at 1090 MHz.  But, for the purpose of collision avoidance, you only need to receive the ADS-B transmissions from a few km away.  And the transmissions are at about 200 watts (8000 times more powerful than FLARM transmissions).  For those reasons the unmodified antenna works well enough.  Note that in my SoftRF there are settings for the maximum distance and altitude-difference to report ADS-B traffic from, so even if the antenna is excellent you will not "see" far-away traffic, unless you change those settings for testing.