I'm not sure if this made it to the list.  Sorry if it is a repeat.

I got to thinking, and I apologize, I was backwards on the pass 
transisters .  Hold the transister with pins pointing toward you, the 
mounting holes should be at 9 and 3 o'clock.  The pins should be closer to 
the left or 9 o'clock hole. When held this way, the base is at 12 o'clock 
and the emiter at 6.  The case is the colector.  On astron supplies, the 
case or shell is hot, will have about 24 volts unregulated dc on it.  The 
emiter is the regulated output.  A simple block diagram would be, 723 chip 
is the regulater and drives the base of a driver transister.  The emiter 
of this driver transister drives the bases of the pass transisters.  The 
secondary of the main transformer is 18 volts ac which goes through a 
bridge rectofier.  The output of this bridge goes to a very large 
electrolitic which will have around 24 volts on it.  The main board is 
usually mounted on top of this large capacitor.  I could go into a bit 
more on what the 723 does such as over current protection and so forth, 
but will keep this sort of simple.  The 24 volts on this capacitor, as 
mentioned above, goes to colectors of the pass transisters which are in 
paralel.  AS I explained in a previous note, transisters, not f e t s, can 
be checked like back to back diodes in many cases.  In this case, the 
2n3055 or similar are n p n transisters, that is why plus goes to colector 
and output or minus with respect to the colector is the emiter.  The more 
positive voltage fed to the base with respect to the emiter, will make the 
transister conduct more, the p in the n p n.    Because this is an n p n, 
positive lead of the ohm meter will show conductance to emiter and 
colector.  Reversing these should show open.  Also colector to emiter 
should show open regardless of polarity.  This is because there is no bias 
voltage on the base.  P N P transisters are just the opposite, negative 
lead on the base for conductance.  The emiter is positive with respect to 
the colector, and the more negative the base the more it conducts.  Hope 
all this is of some interest and makes sense.  N P N are kind of like a 
tube, cathode or emiter is negative, base is gride and collector or plate 
is positive.

73
Butch
WA0VJR
Node 3148
Wallace, ks.