Most of the yahoo groups I've given up on due to poor management and off topic junk. We need to get Fred over here or on the ATM forum. Get his book like Colin says. There are others who have built on his plans, here and over in Europe.

My own recommendation would be to build a solar spectroscope first. If you are already an accomplished builder then maybe you could jump into a SHS. I think Dave Groski is building an SHS currently - he often contributes here on ATM related stuff. If I'm wrong about that I am sure that Dave is knowledgeable about SHS.

I see no problems posting SHS questions here on this forum, many of us are interested in its technology and history, but the ATM forum is your best bet.

Glenn