Other users for L band antenna

Any thoughts on other uses for the L Band antenna originally used for the CHIP version of outernet? Possible to hook it up to an RTL SDR or ESP32?

The passive patch antenna can be used for all sorts of things with an RTL-SDR in the L-Band (about 900MHz to 1.8GHz) The ESP32 is a Wi-Fi / Bluetooth device. I’m not sure if the patch antenna still works well at 2.4GHz.

The active antenna has a built-in LNA and SAW filter. I’m not sure how wide the passband of the SAW filter is. I never bought one to put it on a Network Analyzer.

–Konrad, WA4OSH

This thread may give you some ideas…

–Konrad, WA4OSH

I was able to repurpose the RTL-SDR and LNA to do Fleetnet and Safetynet on Inmarsat. It works ok with my foil and copper wire helix antenna indoors. Let’s make no mistake… The RTL-SDR is all over the place and significantly less frequency stable than the SDRPlay, even with a heatsink. Still, it works. And surprisingly good signal. Just meanders all over…Interestingly, in open air, the RTL-SDR dongle seems to generate less heat than when doing Outernet. Heatsink is barely warm to the touch, whereas when using it for Outernet, it was hot all the time. Not sure that that is all about.

Big thing is it frees up the SDRPlay for other things.

As you can see, the signal is good, but way off frequency according to SDR#. The signal is actually 1539.565 MHz.

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So did you have to spend money on the software or did I miss something?

–Konrad, WA4OSH

Konrad, software seems to be free in the basic version,
73, Wolfgang, DH2WS

Just ordered the new RSP1a, What software was decoding the data? Software I found seem to list rtl2832u , but not the SDRPlay.

You could try this free Inmarsat-C decoder…very neat https://bitbucket.org/scytalec/scytalec/overview

Yes. The free version will only show you maintenance and status traffic, not actual messaging.

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I use Inmarsatdecoder. Have used the Tekmanoid one before he added LES message decoding. I leave Inmarsatdecoder running 24/7 dumping to a folder where I can flip through the messages.

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Good news on repurposing the RTL-SDR & LNA for things other than Outernet…

After several days, I was surprised to see that the metal cased Outernet recommended RTL-SDR, with the small heatsink added (repurposed from an old video card, strapped on with 2 zip ties and some heat sink compound, runs cool to the touch) & the LNA are extremely frequency stable, even better than the SDRPlay RSP-1. This is the setup I used for Outernet and it worked really well.

Fleetnet and Safetynet on the weaker Southbury channel are still on target, even though off frequency according to SDR#, using Inmarsatdecoder. Getting solid 24+ quality reception.

Still using my homebrew helix cardboard, foil and copper wire antenna indoors, pointing at the ceiling, basically.

Used to be I would have to re-center the frequency every couple of days with the SDRPlay RSP-1,but now the RTL-SDR and LNA are solid after over a week, using a Azulletech stick PC for Inmarsat decoder & SDR#.

Will try the Outernet patch antenna this weekend.

All is not lost, investment wise… Now, what can I do with the CHIP??

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