Simple ATU

[Andrew (grayhat)]

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)

[Andrew (grayhat)]

also see

https://www.hamradiosecrets.com/homebre ... tuner.html

although the links at previous post carry all the needed infos

[KL7MJ]

... there's no band switching ...

I was just reading through W6SAI's antenna book, and he has a Z-match that switches in additional capacitance that allows a tuner to cover 160 - 10m!
I have a ZM-2 (Z-match) as well as some small pi and T-match tuners, and I think the Z-match is the most flexible in terms of frequency coverage.

[k8zfj]

I agree about the z match. Have built several blt+ that worked just as well if not better than an em-2

[k8zfj]

I agree about the z match. Have built several blt+ that worked just as well if not better than an em-2

[Andrew (grayhat)]

The Fri-Match is derived fron the Z-match, full story here

https://www.pa0fri.com/ATU/FRImatch/FRImatcheng.htm