I've been a QRP op for decades, and never used a stand-alone balun. I used to use a ZM-2 to match portable antennas, which incorporate a balun. These days, I use a SOTAbeams Bandhopper linked dipole for portable ops, and there's an integral balun. For small rigs at the home QTH, I now use an Elecraft T1, which is unbalanced.
I recently built a QCX-mini, and for the first time, there's an issue: the sidetone is harsh and loud and scratchy, and my RBN results don't seem right, for the amount of power out (~5.7W).
Transmitting into a dummy load results in a sweet sidetone. The diagnosis seems to be I need a balun between the T1 tuner and my balanced feedline (both antennas are doublets fed with ladder line.)
After doing some reading, it seems as though a 1:1 current balun is what I need. Searching through providers of baluns, parts, kits, looking for plans, etc., it looks as though the kit offered by the QRPguys is my best bet/bang for the buck.
Opinions and ideas gratefully solicited.