#Blue dongle LNA failure?

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ionic compass
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Picked up a Blue Dongle at the ADSBExchange booth in Dayton last month, and had it setup and running on a RPi4 for since getting home. Noticed a marked difference in performance over the NESDR Smart that I had been using, with increased range as well as number of aircraft received. About a week ago, I noticed both the range and received aircraft significantly drop.

Since then, I've tried adjusting the LNA gain, switched out the RPi with another unit, and reimaged the SD card with no improvement. I had noticed that the Pi4 had started showing it reached the Softlimit, but had not stated that it was undervoltage or that it was throttling.

Any ideas? I hate to think the dongle failed after only running 2-3 weeks.

warm shuttle
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I'd say it's more likely that something happened to your antenna or feedline - moisture ingress, coax shield broken, etc. If the LNA failed, I think you'd probably receive nothing at all.

ionic compass
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I put the antenna and feed line on my VNA and it checked out fine.

acoustic cosmos
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And how does it perform if you go back to your old SDR?

ionic compass
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Set bot the old and new SDR to run simultaneously. The blue dongle is in the RPi4 and external antenna. The NESDR is on an RPi 2B and is using a VHF/UHF mag mount sitting on a wooden window sill about 3’ higher than the external antenna. Gain on both is set for 42.1.

So far, the NESDR seems to be doing slightly better that the blue dongle. I get 4-5 more Received aircraft on average, and about 10 more miles range. I would have expected more with the blue dongle, as I had seen many more aircraft out to 100nm prior to whatever failed.

warm shuttle
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Now swap the antennas and see what happens.... I should say - swap the connections at the antenna inputs to the SDRs - that should tell you if something happened to the blue SDR or to the antenna/feedline