Here is a link to a really interesting open source automatic antenna tuner kit that can be built inexpensively, I ordered a kit the other day about $60 CDN so am anxiously awaiting for it to arrive. It also has an OLED display which shows by default the power, SWR and selected inductance and capacitance, the kits range from fully assembled to partially assembled, the one I ordered (the most common kit) has the surface mount components installed and the PIC processor already programmed, so just need to solder in the relays a couple of capacitors and the various inductors. These kits are widely available on sellers like Amazon and e-bay by searching the keyword ATU-100.

Here is the link to the resource page.

https://github.com/Dfinitski/N7DDC-ATU-100-mini-and-extended-boards

This is the one I ordered:

https://www.amazon.ca/gp/product/B08TWTYTNR/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

By default it doesn't work below 5 watts, however by winding the binocular toroid with 5 turns each side instead of 10 and changing 3 values in the processor with a PIC programmer (these are about $20.00) it can be used from 1 to 40 watts instead of the 5 to 100 watt default. I ordered a programmer so if anybody in the club ever needs to borrow it, just give me a call.

Here is a Youtube video showing the modification.

https://www.youtube.com/watch?v=dPys_-_wPcQ

Just thought I would put this up for anyone who is interested in building an inexpensive ATU, looks like a fun project, someone in the Phaser user group posted about these so it peaked my interest.

73 Nick VA7ILO