Practical Range Test Results

Using the standard supplied 915MHz antennae, we’re really restricted to immediate local vicinity. In Australia 915MHz tx_power is restricted to 3mw, so that’s already against us, plus being hilly terrain our line of sight is haphazard at best, so we’re looking at what we can to to optimise the antennae.

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Nasty NZ seems to have very relaxed rules around ISM bands for example on 864-868mhz we are limited to 1w with no duty cycle limit or 4w if you have frequency hopping.

So I could put a double-biquad on a sx1262 and not be close to the power limits.

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I got 24km a few days ago.

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Really impressive. Thanks for sharing.

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Isn’t the 1278 100mW not 50mW?
image

The stock antennas are pretty bad. I’ve got three of them now and they are all identical. See the bottom of this post for a VNA sweep.
https://meshtastic.discourse.group/t/antenna-recommendations/2992/17

VSWR of ~3 equates to a loss of about 25% of your power.

The crazy thing about the link b8b8 posted is that is crosses over downtown Vancouver. The noise floor that the signal has to punch through must be really high.

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It seems the max output is 17 dBm/50mw on meshtastic. Could be mistaken however still learning the software side of things.

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hmmm ok, that sucks. Maybe its only location dependent. Would be nice to use the whole 100mW or even more on the SX1262 (160mW or whatever) 22dm.

Edit: looks like its the hardware limit. I retract my statement.

The SX1262 uses 160mw I believe :slight_smile:

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The coders are doing the best they can, with the knowledge they have at the time to program reasonable default settings for devices and regions.

If you think hardware limit was set too low for a specific device I recommend doing a bit of research and start a topic that explains what you found and links to the relevant documents that support your findings. Bonus points for creating a corresponding git hub bug and linking to it.

Regional settings are a best effort to establish defaults that stay within the current understanding of the rules and regulations of that area.

Any of those settings can be changed by someone willing to edit the code and recompile. Part of the community accepted this is A) True for an open source project regardless. B) Sufficient barrier that requires a level of understanding and skill that prevents an uniformed user from selecting settings based on the overly simplistic view that more is better.

That said, many of the settings can be changed using the python interface.

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meshtastic --setchan txpower 100

Sets the output power to the max 20dBm for the SX1278. Geekville has suggested to leave it at default 17dBm because apparently the max rating is for very low duty cycle.

In North America the legal limit is 30dBm so we should be able to use all the 22dBm that the SX1268 can deliver.

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Makes sense to leave it then for sure and 24km punching through Vancouver downtown is certainly good enough for me. I’ll probably get the 22dbm rated board at some point since it also has the updated GPS. Hopefully a 30dbm board is in the works by some supplier, though even with just my own testing at home, a correctly tuned antenna is a far easier way to increase performance.

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Did you tune your own, or buy good ones?

One of my stock 915 antennas was pretty good. The other one I bought off Amazon. I think digikey or mouser.ca are the place to go for good antennas. Amazon is no better than Aliexpress sometimes.

I’ve been pinging off-of your units once in a while, excellent to see those results. We’ve done Queen E to Richmond/North Shore using stock equipment, I’m very impressed!

13 miles from parking lot to mountain to mountain. MITM board was running headless.

Heltec LoRa units with stock included antennas.

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24 miles point to point. Heltec LoRa boards. One set up on a prominent mountain top as a node powered by solar and a 3000mAh battery.


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This is pretty incredible. Thank you very much for taking the time to let the world know about your efforts. Which specific antennas are you using?

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Just the included antennas in the Heltec kits. Haven’t branched out into any aftermarket antennas yet.

Do you think antenna makes big difference?

If so for the price they are very good.

Thanks.