The QRPer Board

After running the numbers, I assume that the design is metric?

73,
Mike, KL7MJ

I've used AA5TB's design for years - I don't think the current multiband approach existed when I first started looking for EFHWs. The plus of his design vs. the more common FTx-43 multiband design is that you can tune it for best SWR for each band. The only downside is that it is a one-band-at-a-tim...

... 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 i...

I finally got my DX-FT8 https://github.com/WB2CBA/DX-FT8-FT8-MULTIBAND-TABLET-TRANSCEIVER/tree/main assembled and on the air yesterday. It's a low power (less than 1w on all 7 bands) FT8 only rig that runs its software on a microprocessor - no computer required. It has two modes of operation. One is...

First I've heard of it. If you have a 3D printer, take a look at K6ARK's designs at https://www.printables.com/search/models?q=k6ark . I use his single lever design for all my portable kits. I've printed a bunch and put them together as needed. The cheap, simple and good enough for me. He even has a...

I received the QRP Pocket Tuner kit from Barb, WB2CBA last week. It's a credit card sized T-network tuner designed to handle QRP power. It took less than an hour to assemble - all of the inductors and capacitors are pre-soldered SMD parts. You just add the switches and SMA antenna jacks. One I had i...

Maybe connect the dummy load to the output of the unun and try again? It won't have a 1:1 match, but you'd see if the SWR remains constant over the range.
How does the unun do with an actual wire attached? And did you find a capacitor or not?

73,
Mike, KL7MJ

Mark,
The website is still at https://azscqrpions.org/ but it looks like they're not producing any kits these days.
Hope this helps.

73,
Mike, KL7MJ

I am looking to build (yet another) 4:1 unun for a Rybakov antenna. Looking online, I see about half of the articles recommend a TX-2 toroid, and half recommend a TX-43. I would think that the TX-2 toroid wouldn't be great for the hgher bands - if a powdered toroid were needed I would have expected ...

Geoff,
My understanding is that the capacitor helps on the higher bands (15/12/10m) but is not necessary for the lower bands. I usually use a 100pf cap in my builds, but I've never really tested its importance.

73,
Mike, KL7MJ