This is the final post in my design of an Automatic Antenna Tuner. It's been a long journey, and I've learned quite a bit. And I hope others have found these posts interesting and, perhaps, even useful.
Links to the other posts in this series can be found at the bottom of this post.
This final post contains all of the updated schematics. They have been updated from their "prototype" revisions (the revision they carried when they first appeared in earlier posts in this series, e.g. "Rev. X1") to my "release" revision: Rev. A.
A Note: Click on any image to ENLARGE!
And with that, here are the final schematics:
RF Frequency Sampler
IO Expander 1
IO Expander 2
Hex Switches L
Hex Switches C
Relay Coils 1
Relay Coils 2
That's it. This series is over!
- The Directional Coupler schematic changed after I first wrote this blog post. The change is described in Part 9 of this series, and the schematic's revision is now A1.
- The Return Loss schematic also changed after I first wrote this post. Its revision is now A1, and a description of its changes can also be found in Part 9 of this series.
- The RF Frequency Sampler schematic has changed, too. Its revision is now A1. I renamed the +5V power going into the circuit to clarify that it is not from the +5VDC power bus, but instead it comes from an NPN transistor.
Links to my blog posts in this Auto-tuner series:
Part 1: Preliminary Specification
Part 2: Network Capacitor Selection
Part 3: Network Inductor Selection
Part 4: Relays and L-Network Schematic (Preliminary)
Part 5: Directional Coupler Design
Part 6: Notes on Match Detection
Part 7: The Build, Phase 1
Part 8: The Build, Phase 2 (Integration of Match Detection)
Part 9: The Build, Phase 3 (Incorporating a Microcontroller)
Part 10: The Final Schematics
Links to my Directional-Coupler Posts:
Notes on HF Directional Couplers
Notes on the Bruene Coupler, Part 1
Notes on the Bruene Coupler, Part 2
Notes on the Monimatch
Notes on the Bird Wattmeter
Building an HF Directional Coupler
Notes on the Twin-lead "Twin-Lamp" SWR Indicator
As always, I might have made a mistake in my equations, assumptions, drawings, or interpretations. If you see anything you believe to be in error or if anything is confusing, please feel free to contact me or comment below.
And so I should add -- this design and any associated information is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.