"micro" qrp EFHW antenna
I was looking for a resonant antenna for SOAT/POTA that would match my (tr)uSDX transceiver.
Heard about this little guy on the DL2MAN forum, I think.
This is a kit from K6ARK, about $20. It's about as small as you can make a matching transformer, just a bit bigger than the BNC connector. I built it as a multiband EFHW using 22GA poly stealth wire.
It tunes great on 40m and 20m, less than 1.5:1 SWR across each when I set it up as a sloper in the back yard.
You can build the same kit into a 1:1 Unun or a random 9:1, just wind the toroid differently.
I'm throwing it in a smaller go-bag with the (tr)uSDX so I can run straight without a tuner and maybe less effort than my QRPGuys vertical.
You need good eyeballs and a steady hand! 😜 That looks like the female version of this one: Ultimate UL Portable Resonant Antenna Build - DIY Micro End-Fed Halfwave Matching Unit (YouTube, K6ARK)
Yep, Jed. Same kit he builds in that video. I may get his 20W version as well for my G90.
Everything is packed tight and getting some of it soldered is a challenge. But it's working really well. I had it out today down in Larkspur and made some good contacts on 20m with the (tr)uSDX.