Once day i decided to build automatic antenna tuner, becouse i'm creazy man who spend time
and monney for building own design devices. Yes, of course twenty years ago that was just one
way to get anything. If you something wanted, you had to build it. But now is too easy buy anything on the internet
and many Chinese producers push prices to low. But i'm more satisfied when using something i builded.
My goal is small,
easy and cheap automatic antenna tuner which can works as locale or as
remote. Tuner has EEPROM memory for store settings for faster
tunning and four interfaces:
- Universal interface is for most radios and contains two signals (TUNE - to start tunning; TX - to transmit with low power).
- BCD interface sends band information by BCD code (FT857, FT897, etc....)
- Voltage interface send band information by level (FT817, IC706, etc...)
- Serial interface is for firmware update and in the future for send band data and remote control.
Projection budget is about 40 € (~ 60 $). PCB board is designed in eagle software and size is limited by free
version restrictions. Due to selected relay are small and i hope, that they can be able to stay alive up to 100W output
power. :-) This is just prototype for basic testing, SW debuging, etc... I'm going to build next version with bigger relays
for power up-to 150W.