Received new LNA, now works

Be careful of the Outernet LNA. I must have zapped it somehow. Not with voltage coming out of 5 volt PS. I think an ESD pulse was picked up maybe from the plastic cover I put over the rig in the evening. The new one is receiving OK now. Ground yourself before you touch any part of the antenna, LNA, dongle, or Raspberry Pi 3.

Well, not for long! About 1/2 hour after seeing SNR of 5+, trouble developed again. Seeing below 2 and getting worse. Could it be the Outernet tuner has gone bad?. Have checked everything, connectors, cables, antenna, PS.

I was getting good signal all day (on 98W) through around 7 EDT and left for a few hours, I’m currently getting no signal, so it may be outernet and not your LNA

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@NN8N - stats collected each minute show me receiving 98W all day with good SNR:

mysql> select count(*),avg(SNR_Avg),min(SNR_Avg) from stats where date_add(TimeCollected, interval 1 day) <= now();
| count(*) | avg(SNR_Avg)      | min(SNR_Avg)        |
|      910 | 4.150350974647553 | 0.26224491000175476 |
1 row in set (0.01 sec)


@cyoung are you currently getting the signal? I briefly got lock again (without packets), but I’m back to no signal. If I don’t see anything by morning I’ll try connecting the antenna to my SDRplay so I can bypass the LNA.

Good strong signal here in Annapolis, MD, at 0723 EDT 15 Oct.


Receiving it well here in NJ, S/N is around 5.0.

One suggestion: if you are using SMA connectors, check that the center pins are intact. Recently, I lost signals when using a dongle on VHF, first thought it was the antenna, went to the roof to check all connectors, everything was fine. Then decided to unscrew all the SMA connectors to re-seat them and found that the center pin on one of the connectors had broken off.


Also along these lines, don’t forget there is something called a reverse SMA which is used on WiFi antennas. If you are using various connectors to go to the Outernet 1.5 GHz amplifier from a different antenna (other than the Outernet Patch), you have to make sure you use the right type adapter. Ken

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Everything is back to the normal 5.0 dB SNR again this morning on my end (my setup had the patch, LNA and Dongle all directly connected so the issue wasn’t the connections). Since nothing physically moved the issue was either the signal going off air last night or a defect that was exposed through thermal cycling (nights are getting cold).

@zoltan has also been seeing issues related to colder temperatures. How cold was it for you?

The other way around. Last couple days have been mild. Before that very hot, near 100 F. That’s when I put fan on near the rig. And it
seemed cooling improved the SNR a bit. But, later I started having trouble. I suspected the heat and cooling damaged something.
I ordered another LNA, but that wasn’t it. I’ve been checking everything. Rare to see SNR above 2 now. Not usable. So today I ordered another Tuner.
If that fixes it, I sure hope I can get a some sort of refund. The parts are only a month old. Not a happy camper right now.

Yes, if the problem is the radio, then you’ll definitely received a refund.

Thanks! The Tuner is out for delivery tomorrow, Monday.

After watching it alll weekend the issue on my end is definitely a bad LNA, SNR was under 1 when not working (compared to 5-6 when working). If I take the LNA out of the chain the SNR is 1.5-1.8 Not sure where the issue is, but later this week I might be able to get time with a good enough analyzer to try a diagnosis. When working the ambient was in the 60-70 range, and the first failure was probably a little below 50. Unfortunately MAX12000’s footprint makes it hard to validate the joints, but once I get a replacement installed I can try to reflow the part.s