ENFIN le 1er message #Meshtastic #EU868 en Long Fast envoyé avec confirmation reçue : Nancy - Liverdun. 12,6 km d'après mon device (modulo précision des GPS d'un coté et de l'autre mais ça doit pas changer tant)

J'ai pris la seule antenne reco sur le site Meshtastic qui soit en 868 MHz et dispo en Europe avec des frais de ports… GIZONT 17cm, genre 8 et des poussières FdP inclus.

Presque toutes les antennes qu'ils recommandent sont pour 915 MHz (USA), une 433 MHz et une 906 MHz (US aussi? 🤔)

Installation des 8-Channel-LoRaWAN-Gateway M2 Starter Kit von Seeed Studio

--> https://cool-web.de/lora/seeed-sensecap-m2-multi-channel-lorawan-indoor-gateway-installation.htm

#LoRa #LoRaWAN #Seeed #SenseCAP #M2 #Gateway #Sensoren #XIAO #ESP32S3 #DHT11 #Grove #Base #Shield #Wio #E5 #STM32 #EU868 #Funk #DIY #Elektronik #Maker #Mikrocontroller

#meshtastic #lora #antenna #eu868

Last days i suggested using this antenna from aliexpress for lora 868 communication

https://techhub.social/@gafu/113653494874396257

I suspected, they send us_915 antennas everytime.

I got new one again and measured them.
Looks like they send the same antenna for 868 and 915, but the resonance frequency is inbetween the two frequencys

Resonance or best adaption is at 890mhz

Without any mod this antenna is useable with low losses at 868 and a good one.

Swr at 868 is not perfect because impedance mismatch (z is 35 ohms, perfect is 50 ohms) but its way better than all the tiny ones delivered with the lora trx.

Still recommend this one for
Good RF output at relative little antenna size
Low price
Foldable design

VNA curves below

What does the curves mean?
At vswr 1.8 you loose 8% of transmitter power to back-reflection and get 92% to the antenna. Not bad.