Here are results that I obtained using a pocketVNA:
400 kHz - 3 GHz, S11:
Closer view, 1.4 GHz - 1.9 GHz, S11:
Antenna is tuned at about 1.605 GHz, which is about 63 MHz high. Maybe manufacturing variances accounts for the large variance in SNR that some are receiving (haven’t been following this much lately).
1.4 GHz - 1.9 GHz, Smith chart:
What is the model of VNA you are using? Our next antenna model should have tighter tuning performance, since there will be less human-input.
what is the test environment? test jig? was this performed with antenna in free air?
Sitting on my desk. No. No.
Don’t laugh at my request: if you find some time, can you please put a pair of pliers near the antenna and check whether that pushes the resonance over to the Outernet frequency?
My SNR went up significantly doing this. I am now approaching 1.5 million packets received with less than 70 bad CRCs.
I laughed, but I’ll try it anyways! We don’t have any channel locks around, but maybe some pliers of comparable size. Not sure if the rust spots help bring the reception closer, but we’ll try something comparable.
Haha. It actually worked even better with very fancy new pliers! And it depended on how much you opened the handles. But since this is an outdoors closet, I only sacrificed the oldest pair I had around to be left there permanently.
This all happened by accident. I tuned until everything worked fine. Then I cleaned up and put all the tools away and SNR was way down. Took a while until I realized that the pliers made the difference.
See below. I moved the wrench closer each time in the tests. The last one was the best, it was almost touching the antenna. It’s probably somewhere in between a slight improvement and no improvement in my case.
“Marker 1”, “Marker 2” - no wrench
“Marker 3”, “Marker 4” - Wrench3 trial (pretty much touching the antenna).
