Bitx40 CW homebrew

This month I completed the build of a 40m Bitx trx  to take along when on holiday. Output is 5 Watts.

I ordered mine here.

Apart from this you need also need a case.

There is a very active forum on this kit here.

The kit is SSB only, no CW. BUT Jerry – KE7ER – posted his CW mod in the forum so now mine can do CW as well. Thanks Jerry !

The VFO is made around an Arduino Nano and a Si5351A chip, the combo is called Raduino and ready to use.

The Raduino comes with v1.01 installed. On the forum Allard PE1NWL – posted  v1.09 in which he implemented

  • switch between VFO a and B,
  • use RIT,
  • switch between USB and LSB,
  • easily calibrate the VFO for both sidebands.

Thanks Allard !

I also installed an CW audio filter, i ordered this one

After building everything in the box, the unit received o.k. but had no output power.  Transistor Q13 turned out to be defective.

Luckily we have a small electronic parts shop here in Harderwijk with a great selection of all sort of components and a guy who knows his stuff, so a replacement transistor was no problem.





Teun the owner also had a retro handmike in his shopwindow.

For 2 euros you can’t go wrong…

After replacing the tranistor the output power was 5 Watts, enough for most european QSO’s.


All in all it was fun to assemble, and is fun to operate.

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