I started wspr via the 80-10 desktop unit with couple switchable fan dipoles in the attic of my home. 30/17/12 & 40/20/15/10. Running the given bands for a week or two then switching to the other bands, reconfiguring the software as per bands i chose. The dipoles are resonate with acceptable match so there was no issue there & of course good for ssb & ft-8 like digimodes. After searching around the forum here i noticed ops were having good luck with endfed random length wires and able to get very good results on many bands. I purchased a 9:1 unun (LDG Electronics part # LDG-RU-9-1) In my quest for more bands with reasonable swr and began fiddling with different lengths of wires. Using an antenna analyzer helped tremendously to see just what the best wire lengths were. You can roll your own unun (internet search) i choose purchase. I believe i seen here on the forum comments that the unit will radiate a signal unharmed on a non resonate antenna. My random wire has swr of 3 (the poorest) and still gets spots.

Thank you for responding ! Harry has graciously offered to take a look at the unit. I do believe your comment in best practices to not only disconnect power i.e. shutdown the unit but also disconnecting the antenna while operating hf. (perhaps not necessary for all operators applications as thier situation may be the transmitter antenna and zachtek antenna have enough physical distance from one another) My setup is such that the antennas are relatively close in proximity & i feel it would be advisable for me to disconnect the 80-10 unit antenna/power while operating hf . I do believe i did not always disconnect the 80-10 antenna while operating hf modes (ft8,ssb). So, we shall wait and see what the prognosis is and go from there. I do know the zachtek desktop 80-10 unit is a wonderful device and of course wspr a great experience for those of us interested in propagation. Kb0vyg Bill