[mwoodruff]

Attached is a clip from a 16b schematic that I found online.  

   

Having culled the forum for info, I still have a few questions (my xmas gift to you!):

1.  What is that thing with the two concentric circles in the lower-left quadrant?  A brief search of symbols online didn't reveal anything.  It does not appear in other 16b schematics.

2.  Re: the line-filtering caps directly off the mains:  Are these y-caps because they each go to a (common/chassis) ground?  Or are they x-caps because they bridge the mains (L-N)?

3.  Because the caps are upstream of the on-off switch, doesn't this mean that the chassis is always hot?  (I get the voltage divider and minimal current points, but why not move the switch upstream of the caps?  Or does this mean that you can get shocked if you touch the switch and a ground at the same time (if the wall plug is not spaded)?)

4.  Finally (for now) if you ground the chassis to earth (cold water pipe, radiator, etc.) does this eliminate any possibility of a shock from the chassis (per 3 above)?

5.  Another "finally": If I want to put a fuse in the power circuit, where should it go?

Thanks in advance,

Matthew W. Woodruff