Simple ATU
Posted: Mon Mar 31, 2025 3:33 pm
Covers all bands from 80m up w/o any band switching, for QRP it can be built using polyvaricons, in effect the hard to find parts are the twin air variable capacitors
full informations here
https://www.pa0fri.com/ATU/FRImatch/FRImatcheng.htm
and here is a nice version
http://dl4cs.de/funktechnik/ant/fri-match/en.htm
this ATU is easy to turn into a remote one since there's no band switching it's just a matter of using stepper motors or R/C servos to turn the variable capacitors plus a couple of relays for the hi/lo Z switching and for the ATU bypass (see second link above)
full informations here
https://www.pa0fri.com/ATU/FRImatch/FRImatcheng.htm
and here is a nice version
http://dl4cs.de/funktechnik/ant/fri-match/en.htm
this ATU is easy to turn into a remote one since there's no band switching it's just a matter of using stepper motors or R/C servos to turn the variable capacitors plus a couple of relays for the hi/lo Z switching and for the ATU bypass (see second link above)