ΜBITX

Notes on µBITX assembly and use.

Assembly

Used a cookie tin as a case.

Mic assembly.

Antenna setup

Inverted V dipole made with Amateur Radio Supplies 20m dipole antenna wire (two 18' strands, trimmed, wrapped around insulators, strung up in attic) and 450Ω window line.

QRPGuys Multi Z Tuner

QRPGuys 12W dummy load

Mods

Applied during assembly:

• Added a fuse before diode (succeeded?)

Attempted after tested working:

• Mitigating heat on LM7805:
  • Added a small 5V switching power supply before LM7805 (failed; created too much noise)
  • Relocation of LM7805 to case (succeeded, but got leads switched the first time and smoked the nano)
• Dim LCD (failed—no effect)

Plan to attempt at some point:

• TX LED
• SWR meter
• Red-on-black display (for night-time operation)
• Foot-pedal controlled TX
• Some sort of audio pre-processing?