LNA for RTLSDR/ What else do I need?

SatNOGS Hardware
1

Hello!

I have a Yaesu rotator, computer controller, RPi3, and RTL-SDR, and a UHF/VHF antenna. What is the best LNA to order to use? Links would be helpful as well, just wanting to make sure I get the right one! Also, is there anything else I should add to my setup? Thanks!

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An LNA can be used to reduce the noise figure of your receiver and to add gain before filtering the input signal. I just ordered a couple of “70cm 430-440MHz Filter | RTL-SDR” from E-bay. I’m going to amplify and filter right at the antenna before incurring the losses from the feeder coax.

Antenna --> LNA (+10-15 dB & low noise figure) --> SAW Filter --> Bias Tee ====>Coax===>
Coax===> Bias tee to supply LNA (and filter if it’s active) ==> RTL-SDR.

There are many to choose from. LNA4ALL?
–Konrad

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Hey @elkins_ka ! Also given you have a directional antenna setup with a rotator, you could probably try some first results without an LNA. You could still get some nice observations and decodings from it (especially if you have a good latest rtl-sdr)

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I agree. With large antenna gain, you may not need an LNA.

Does anyone have a typical Cubesat link budget?
The input sensitivity of an RTL-SDR at 135 and 435 MHz ?
The noise figure?

–Konrad

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I use this LNA on my ground station, along with a yaesu rotator and M2 UHF/VHF LEO pack:

You can see some of the results here: https://network.satnogs.org/observations/?future=0&good=1&bad=0&unvetted=0&failed=0&norad=&observer=&station=2

I’ll note that my ground station is about 35m from the SDR using LMR-400 with the LNA mast-mounted, so it helps to push through any coax loss. Your configuration may differ and as pointed out already you might not need one. Try without one first!

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Hi just bought this LNA. hasn’t arrived yet. What are you using as an enclosure for it?

-Henry

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I have an outdoor cable/telephone box that I house the diplexer, LNA, and coax connections. You can see the side of it here: https://network.satnogs.org/media/ground_stations/kb9jhu.png

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great idea, that looks like it might just what I’m looking for. Thanks!

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I have an outdoor cable/telephone box that I house the diplexer, LNA, and coax connections.

Nice box. Do you have the make and model, please?

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Had to dig deep in my amazon history for this one! :slight_smile:

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