David,
you'll get a lot more on this subject before you're done and it will 
all be good info.  The linear supply has been around forever; for a 
given amount of power it is pretty heavy, sometimes hums a bit and is 
very reliable.  Astron is the name that comes to mind, although all 
of the transceiver manufacturers have their brand name on linear and 
switching supplies as well.  I'm sure that I have a Kenwood and an 
Icom linear supply down in the shack as well as a couple of 35 amp Astrons.
Switching supplies are newer technology and seem to have improved 
over the years.  There were horror stories of their losing their 
regulation and frying the equipment that they were powering but you 
never hear those stories any more.  I have an Icom switcher that will 
run their 100 watt gear and a couple of others that all work well and 
very quietly.  So R F noise has been no problem for me.  The 
switchers are physically very lightweight and I think a person could 
safely go that route these days.
I'm sure that there is a lot more technical info on its way.
Hope this helps.
Pat Byrne, K9JAUAt 03:59 PM 5/25/2013, you wrote:
>Hello List:
>
>Apart from the fact that they're 2 basic types of power supplies(linear, =
>and "switching), I know very little about their relative =
>merits/shortcomings except that the latter type seem to be much less =
>expensive, smaller, but perhaps at the price of a little more noise.  It =
>seems that many people on this list use an Astron supply providing from =
>25-30 amps.
>
>I could use a primmer/tutorial on supplies, and the practical reasons =
>for  preferring one type over the other.
>
>73,
>
>
>
>David S. Pearson-wa4dsp