New LNA Amplifier and RTL-SDR

I received the new Outernet LNA and RTL-SDR today, and ran some comparison checks finding no significant difference in SNRs or RSSIs between the new products and the original Alpha Lantern components.

Granted my view of Americas may not be the best, but I consistently get a 3 - 6 SNR 24/7. Ken

I’m revising my previous comment. Over the last 12 hours my recorded SNR performance has significantly changed on an overall basis. My SNR lows have hovered around 5 dB and my peaks have generally been over 8 dB.

What has really caught my eye now is my signal level bars in the top right have all been full, and my packet failure count is low.

Additionally, the SDR is slightly warm to the to the touch rather than very hot. Since actual signal levels appear to the same, the RTL-SDR does outperform the original SDR based on signal-to-noise ratio. Ken

I had the e4000 experience a lot of others did where it worked out of the box and pulled 5-7 dB SNR, and then eventually degraded to unusable. I switched to a rev 2 RTL-SDR Blog dongle with the non-software bias-t and it was night and day, I’ve had it running a few weeks now with very stable results.

Worst SNR I’ve seen since changing was in the mid 6’s on a day with bad weather… ended up returning one of the two e4000 dongles (the other was outside of the 30 day window) and have been pleased with how well it’s working. My only concern now is finding an enclosure before to protect the antenna from the inevitable winter weather that will start soon without sacrificing too much signal strength.

Hello NN8N

Here’s my very simple solution - - an upside down PVC storage container. The PVC does not have the same attenuation effects Outernet’s original ABS had. I have the Alpha Lantern propped up on my deck rail and tied so it doesn’t get knocked over. The power cord goes to an outside wall plug.


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I use a trash bag over the tripod that holds the antenna.

I just received my RTL-SDR and experienced low SNR, could barely get over 2db now it is a solid 11.5… Thanks for the info.

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Additional monitors SNRs and Signal Levels this week have show significant improvements using the New LNA and RTL-SDR. I am getting SNRs of 11! when the Signal Levels get high, and am consistently connected with SNRs of 4 - 6 with lower Signal Levels. All signal strengh bars are solid, and Symbol Error Rates are zero to low. Packet Failure Counts remain low.

This is all on an Alpha Lantern with a standard CHIP running rxOS Version 3.1 and an exposed PATCH antenna on Americas 98 W. Ken

I’m just now seeing this. In the receiver demodulator there is code which “tracks” the signal for both frequency and phase offset (errors) which degrade performance. This will be a phased locked loop. This phased locked loop tracking is aided by using known data in every “packet” from the spacecraft to drive the frequency and phase errors to zero. You wish it would do this quickly but it takes long time so that once it gets near zero it is resilient to interference, weather, etc.

I watched mine improve SNR for quite a while.