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A Versatile Tuner for SOTA Activations by KX0R


Thank you for many S2S contacts!
No I understood why it was possible.
How about publishing this material in QST or other amateur radio magazine?
This tuner concepts may be interesting not just for SOTA forum members, but for any QRP lovers.

73! Oleh


One if the best threads on the reflector. Thank you again George.
73 de OE6FEG

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Thanks for your comments!

The QRP Quarterly published my article last year. It also was published in Spain with a few additions.

It’s still here online, which is nice. A few people have built similar tuners that work well, and that is what I hoped would happen.

My larger tuner works well down through 60M, and up through 15M, but I need to build some new tuners for higher frequencies and lower frequencies. When the sunspots return, great times await, perhaps on 10M with easy DX during the day.

With the virus crisis, this is a good time to stay home and build tuners and other gear for SOTA!




Just finished the toroids this morning:

I used L3 as is from my old tuner, just shortened the leads a bit. However, I wanted to rewind L1 and L2 (coupling toroid) to get the windings as tight and neat as possible. I also left longer leads to get to the additional variable capacitor between L1 and ground.

Other improvements include shaping the holes in the enclosure with a file so they have flat sides to grip the switches and BNC. I’m trying to think of a way to improve the connections between common on the switches, and the input and output. I’ve plenty of time to think it over.
73 Matt