Meshtastic

The importance of GPS antennas (and request to 3d case & documentation people)

Hi,

So I’m currently locked in a building and noticed that my stock TTGO GPS antennas would just barely get signal. However, I did have this cheap amplified antenna. OMG SO MUCH BETTER. If you need optimal GPS data for your usage, I recommend you buy one of these $4 wonders.

Also - I noticed that even the few layers (6?) of PETG in my cases made a huge difference in GPS signal quality. Removing the antenna from the case helped a lot. Therefore if anyone wants to work on either of the following two things that would be awesome:

  • Add a note to docs/FAQ.md mentioning this issue and the possibility of switching to a better antenna.

  • If you are making 3D printable case designs - make sure to use only a very thin layer over the GPS antenna.

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@geeksville I drew it TTGO T-Beam V1.1 w/ NEO-6M PCB shell I am not good at art design, if any brothers can design better patterns, please share with me, thanks

Please use M2 type PCB screws and copper posts to fix
After downloading introducing easyeda
EjsDkpjWAAAUx4k EjsDkpjWAAEVUEi

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The 3d case cover I use is thinner around the GPS antenna. https://www.thingiverse.com/thing:4168101
Pointing the case cover towards the sky (45ish degree) helps a lot indoors.
Have the bigger GPS antenna too, it works so much better…Unfortunately does not fit inside my case

Thanks for that hint, i fortunately read about this while in the final stages of my case design, it should only be 2 walls around the GPS antenna now :slight_smile:

I’ve got a Beitian BT-18A (18185mm) antenna on the way, as that may be possible to fit into my case with a small bump on the side, but the 28mm version will be too large…

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I just received these yesterday.

They are roughly twice as wide about the same height and depth as the GPS antennas that come with the TBeam.

From a cold boot, I had a lock inside of 10 seconds. When you swap the antenna though, be sure to apply quite a lot of pressure to get it to seat. When I first attached it, I was not seeing any satellites. When I picked it up and applied a little pressure I had 9 satellites, removing pressure it went back to 0.

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Is there any difference in accuracy, or just speed of picking up satellites?

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It improves the signal received from the satellite network. With improved signal, you get a lock on more satellites which would result in better accuracy, faster location acquisition and faster almanac downloads.

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I got a new GPS antenna to replace the default one; it is ceramic and about one inch squared. However, it’s got a metal underside, and I put that on top of the T-Beam (when trying to fit it into a PET tube), and I got a metallic smell and now the battery doesn’t work anymore (the board works fine when plugged into the USB port). Is it possible that I have fried some component by having the metal bits on to of the board? Or does it draw more power than the original one and this damaged something else? I want to avoid a repeat when I try this with another board… :frowning: