,

I have heard that Astron is very tight-lipped about tech info for their
power supplies. It isn't just Astron, however. I have a Magnetech RV

I have bought several differant kinds of the Astron linear supplies and they
all come with a schematic. They just have minor changes of the standard
lm723 type supplies. I have not seen the switching supplies so can not
comment on them. I just don't like the switchers. Not as simple to repair
as the others and some can generate RF noise.