Rich,
 
   I've included some pictures to help in the description.  The wire rig shown is one that
   I made for another portable and has 7 connectors.  That set needed 65 volts so 
   7x9 = 63 volts was close enough.
 
   Ok, here are the instructions:
 
1 - Take two battery connectors and connect the red wire from one to the black wire of
      the other one.  To connect the wires, simply twist the bare ends together.  If the
      connectors didn't come with the ends stripped of insulation, you'll have to do that.
      This is where a wire stripper would come in handy.  Also, if you have a soldering
      iron and know how to solder, you should solder the connections together.  If not,
      just twist them tightly.   Finally, wrap a piece of tape over the joint to insulate it. 
 
 2 - Then take another connector and connect its red wire to the loose black wire of the 
       first pair.  Continue this, connecting red to black until all five are in one long string.  
      This is kind of like what I show in picture #1, except that you'll only have the 5 connectors 
      instead of the seven.
 
 3 - Now you need to connect the two loose ends (one red and one black) to the battery
      connector of the radio.  This is the thing that has a piece of cardboard with wires going
      into the radio and two little metal caps.  These caps look like bigger versions of the caps
      on the 9 volt battery connectors and are the connectors to the special 45 volt battery
      that the set was designed to use.  You'll see that I marked the cardboard with a + sign
      by one cap.  You should connect the red wire from your jig to that cap and the black wire
      to the other cap.  Doing this is the hardest part.  If you can solder, that is the easiest way,
      just solder the wires to the caps directly.  Otherwise, strip off about 1 inch if insulation from
      the two loose ends, loop each one around the appropriate cap (red wire to +, black wire to
      the other) and twist the end together.  Finally, wrap some tape around the caps to help hold
      them in position and insulate them.
 
 4 - Now make sure the radio is off by turning the volume control all the way counter clockwise
      until you hear it click.  Then put the D cells and the 9 volt batteries into the radio as shown 
      in picture #2.  Make sure the + end of the D cells is toward the top of the radio.  There is 
      plenty of room in the bottom for the 9 volt batteries.  You might want to stuff in a little bit of
      paper to keep them from rattling around.  The final will look like picture #3 (except that 
      you won't have the spare 2 connectors hanging there).
 
 5 - You are done!  Close the cover and turn the radio on.  It should play.
 
  If you have any problems, feel free to e-mail me.
 
Good Luck,
 
Hank
 
P.S. I estimate you ought to get about 10 hours from a set of batteries, depending on how
        loud you play the radio and how fresh the batteries are.  Also, if you're not going to use
        it for a long time, take the batteries out!