I learned about the Sub-1€ TRX challenge from Ismo (OH2FTG) - thank you (maybe for getting me addicted?).

The constraints

  • Sub-1€ TRX, with LCSC parts.

  • This excludes the PCB, so it can be 10x10 2-layer or 5x5 4-layer.

My Design

  • WIRELESS WL4456 (TX) and WIRELESS WL550 (RX) pair - 17 cents

  • T/R switch: TECH PUBLIC TPAS169-73LF - 16 cents

  • 13.56 MHz crystals (HY13560M49SBSMDOB1R30 / 8DSC135G0012L) - 5 cents * 2

  • MCU: PY32F002AL15S6TU SOP-8 from Puya - ~11 cents

  • Misc: Active Buzzer, Morse Key, Push buttons, Jellybean passives - In the remaining budget

  • Use (visual) LED instead of the buzzer - Stealth and saves more cents - Just like in Raazi movie :D

  • Monopole wire antenna is enough?

  • Use phone for supplying 5V power via USB

  • Who needs a PCB? ;)

Further savings

  • WIRELESS WL2800 - 2.4 GHz transceiver chip - 11 cents!

Future ideas (for expanded budgets)

  • Use CH552G SOP-16 for connectivity with Android phone (CW keyer, Auto-Decoding, etc)

  • Use INNOTION MMICs for ~1W output :=)

Cost

We have a UHF TRX design in under a Dollar / Euro ;)

Time to build

Less than 30 minutes

Resources