I built the transmitter almost 20 years ago. It is in the larger box,
which originally housed a Heathkit DX-40. There is a lot of soul in that
old machine. Details on this construction project are here: https://soldersmoke.blogspot.com/2021/12/junk-box-sideband-from-azores-2004-qst.html (The
smaller box is a Barebones Superhet receiver set up for 17 meters.) In the 2004 QST article I discuss