On Fri, 19 Apr 2024, Nick England wrote: > https://www.navy-radio.com/manuals/tty/rtty-journal/1963-1972/PDF/VO15NO8.P > DF > > Assuming that is a Mainline TT/L-2 ??? > The late Keith Petersen W8SDZ was a co-developer with Irv Hoff and I've heard him say he thought the TT/L-2 was a better performer than the ST-6.