Alpha arrival status

Got the alpha today, it seems the cross continental shipping is rather stressfull :wink:

What failed:

  1. Battery came loose (superglue insufficient?)
  2. Antenna came loose (two of the prongs holding it in place came off)
  3. Battery appears to be dead (drops to 0,5V when disconnected from charger after 1h)
    I know that it should charge 8h but as far as I understand LiPos this is presumably beyond repair.

I fixed the first two with 2k glue and am currently looking at battery options.

When powered via USB, the C.H.I.P emits quite a lot of heat, by the way.

Exploration to be continued…

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Oh wow. It was basically destroyed. Ok, back to the drawing board on the holding mechanisms. Thanks for letting me know about this.

Yes, the CHIP runs really hot, but it works fine. It’s been tested up to 65C.

Please let me know if the battery has completely failed–I’ll send you another.

If you are literally using superglue then something flexible like Sikaflex is going to be a lot more tolerant of bending and bashes.

There was one placeholder piece that did use superglue, but I was referring to the other components. The placeholder is already getting molded into place, but the radio and amp moving around was not expected.

Ok, the battery is not really dead. \o/

I was about to toss it and in a last ditch attempt hook it up to a LiPo charger when I realized that the connections were bad.

The LiPo itself is sitting in a black plastic holder. Contact is made through two metal tongues / contacts. These got bend so these were no longer pressed against the battery contacts.
I guess this is also an artefact of transportation. My theory:
When the package gets thrown around, the high mass of the battery causes the metal contacts to bend. There is no real spring tension here just thin sheet metal whose material does not seem suitable for that job.

Going forward I suggest to replace this contraption with LiPos that have the JST directly attached to it. Something like this (same phyiscal size & capacity). Perhaps this can be sourced with a longer wire and the problem should be eliminated.

Yes, ideally we make a similar casing for the Boston Power battery. That particular battery is designed for very high temperatures and is also a single cell battery, which removes any risk from cells being unbalanced while charging.

Have you gotten a chance to point the receiver yet?

I have received my Alpha Lantern and it is set up and running. Bad weather here in Maryland precludes putting in ideal reception location for now.

One question - - after charging overnight thru the micro USB plug, I connected 1 of the 2 solar arrays with the bayonet plug to the Lantern. What is the purpose of the second solar cell with the female USB plug? (It seems I read this somewhere, but I can’t find it). Ken

Alpha Lantern has been running in Maryland looking at I4F3 (215 deg compass direction, and black stick in 2nd hole) for three hours with clear look at sky on overcast day.

Librarian looks as follows:

Every once in awhile the “Signal state” goes from 0 to 2, but SNR remains in the minus as shown. Will monitor longer before taking front cover away from antenna. Ken

Yes. I had to correct the frequency which caused me some grief.
It seems it’s barely working:

Signal state is mostly “3”.
Clear sky at night, no obstructions.

Symbol error rate is the most important value. Your is 8%, which is high. Let’s leave it on for a while and see if the files start coming down. Well, they are coming down regardless. What I mean is whether the all of the error correction can turn the packets into files.

I got it to 6-7% by careful aligning it within approx 3 degrees.
What worries a bit is that it seems to be at the edge with what I consider very good conditions.

@kgbvax I wondering if it’s just local interference for you. @zoltan Would an additional SAW address this issue? His SNR should be much higher. I’m close to downtown Chicago and I get 6dB of SNR.

@kenbarbi Would you mind taking your unit apart and using just the naked antenna? That negative SNR is not a real value. Unless there is code lock by the demodulator, all the values will be garbage.

Naked antenna now exposed:

Looking at a clear sky, I’m now getting a SNR of +1.5 to 2.0 db :

I’ll check status in the morning. Ken

Could you remove the solar panel and see how that impacts SNR?

Removing the solar panel had a small impact, In original configuration, I was seeing SNRs bounce between + .01 to +2.0. With solar panel removed, SNRs bounced between +.5 to + 2.5. Clear dry skies (at 0800 EDT) here in Washington, so I will monitor and report later. Ken

Update - - with the solar cell removed the Lantern goes dead in 30 minutes. It has been plugged in all night (16 hours) so should have a full battery charge, but not enough to run the device. I plugged both solar cells into the dead device, and it has come come back to life.

One cell goes to the bayonet and the other thru a USB to Micro-USB cable to the power feed input

I am getting SNRs peaking to +6.50 now. Symbol error rate is .01, received packet count 436 packets, failure count 2, signal state 4, and 2 bars in the signal strength barometer display.

Any thoughts on what to check under the hood? Ken

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I made a few experiments, with cover, without cover.
Moved it around (one story up).

In all cases, SNR is worse than last night: 0,5 -1,5 dB during daytime, 40% cloud cover.

FYI, I don’t use the solar panel at all.

Hello - - are you charging unit then deploying it, or are you providing external power to Micro USB from a wall wart? Ken

A new problem developed just now. With the 2 solar cells connected (since the battery won’t drive the Lantern), the whole thing shut down. I’m thinking since the Lantern is in the direct sun, perhaps there is a heat build up issue?

Any thoughts along those lines? Ken