Thank you very much for all that you have shared!!
I just now loaded yagi.exe on my Win 10 desktop clone.
The pgm opens OK; but it presents two fields for each element (except the driven element). Sorry; but I have no idea what the pgm is looking for. So far, the only thing it does reliably is crash.
And also, the yagi I had in mind has 2 reflectors and 4 driven elements.
Should I be looking elsewhere?