The original rubber antenna must be tuned!

A project log for LoRa APRS 433 MHz battery powered beacon

It has a WiFi Access Point for easy real time configuration. It sends: ham callsign, GPS or fixed coordinates, altitude, Volts and mA

guidoGuido 12/23/2021 at 10:360 Comments

Hi all!

I've found that the original antenna of the LILYGO® TTGO T-Beam is tuned at around 470MHz and that at 433.750 MHz the return loss is -3dB (half power in transmission is lost).

See how I solved in the "Details".