‰  NOW 40 WPM  ‰  
IF DESIRED, HOWEVER, YOU CAN PRESS AND HOLD THE ON MENU BUTTON, ENTER THE
MENU, AND SELECT INDIVIDUAL COMPONENT MANUAL MODES OR THE PROBE
COMPENSATION FUNCTION.  WHEN IN THE MANUAL MODE FOR INDUCTANCE, YOU WILL BE
ASKED TO SELECT A 1, 15, OR 200 KHZ TEST FREQUENCY.  FOR THE RESISTANCE
MANUAL MODE, THE RESISTOR IS ANALYZED ONLY AT DC.  FOR THE CAPACITANCE
MANUAL MODE, YOU WILL BE ASKED TO SELECT BETWEEN DC USED FOR LARGER
ELECTROLYTICS, 1, 15, OR 200 KHZ.  AND I

BECAUSE THE PLASTIC GUARD DOES NOT LET YOU SET THE OPTICAL SENSOR CLOSE
ENOUGH.  WHAT THE OUTPUT LOOKS LIKE  RATHER THAN QUOTE THE MAGNIFICATION
NUMBERS, LETS LOOK AT SOME RESULTS.  AS YOU TRY TO USE THE SCOPE, YOU WILL
QUICKLY FIND TWO LIMITATIONS.  IT IS A MICROSCOPE, AND AS SUCH, IT IS
DESIGNED TO LOOK AT FLAT OBJECTS, SUCH AS A SLIDE SITTING ON THE BASE.  IF
YOU PUT THE REVERSE SIDE OF A PC BOARD UNDER THE LENS, ANY COMPONENTS ON
THE OTHER SIDE OF THE BOARD THE COMPONENT SIDE WILL RAISE THE BOARD ABOVE
THE BASE SURFACE.  MOST OFTEN THE SIDE YOU ARE LOOKING AT WILL NOT BE
PARALLEL TO THE BASE, WHICH MAY RESULT IN SOME FUNNY EFFECTS DUE TO THE
OFFSET ANGLE.  IN ADDITION, YOU MAY NOT BE ABLE TO TAKE ADVANTAGE OF THE
FULL RANGE OF OPTICAL MAGNIFICATION WITH FOCUSING, DUE TO THE HEIGHT OF THE
PRINTED BOARD OVER THE BASE.  THESE EFFECTS SHOULD NOT DISCOURAGE YOU.  THE
PICTURES HERE SHOW EXAMPLES OF WHAT YOU WILL MOST PROBABLY SEE.  FIGURE 9
IS A SHOT OF A MONOLITHIC CERAMIC CAPACITOR, MEASURING APPROXIMATELY 3
MILLIMETERS 1/8 INCH ACROSS.  THE VALUE CODE 104 STANDING FOR 0R1 UF
BECOMES CLEAR.  FIGURE 10 SHOWS A PC BOARD UNDER CONSTRUCTION WITH SOME,
BUT NOT ALL, OF THE COMPONENTS MOUNTED AND SOLDERED IN PLACE.  THE TWO
CIRCLES AT THE TOP ARE PLATED THROUGH HOLES THAT HAVE NOT YET BEEN
SOLDERED.  THE LEFT MIDDLE CIRCLE IS A GOOD SOLDER JOINT WITH A STUB OF THE

SOLDERED LEAD STICKING OUT TO THE LEFT.  THE SMALL DOTS AND SPLASHES ARE
FLUX.  IN THE MIDDLE IS A SUSPICIOUS JOINT THAT LOOKS LIKE IT NEEDS MORE
SOLDER, AND THERE IS A GAP TOWARD THE TOP LEFT THE STUB OF THE CUT LEAD IS
AT THE 2 OCLOCK POSITION.  IN THE FINAL, RIGHT HAND CIRCLE, THERE IS A GOOD
SOLDER JOINT, BUT THE LEAD STICKING THROUGH WAS NOT CUT OFF AS CLOSE AS IT
COULD BE.  MOST PROBABLY THIS WILL NOT CAUSE ANY PROBLEMS BECAUSE THE AREA
AROUND THE PLATED THROUGH HOLES IS COVERED WITH AN INSULATED COATING.  IF
THE COATING WAS NOT THERE, THE EXTRA LEAD MIGHT GET BENT DOWN WHEN YOU
HANDLE THE BOARD AND SHORT TO THE SURROUNDING AREA.  FIGURE 11 IS A SHOT OF
ANOTHER BOARD, SET UP TO SHOW THE REFLECTIONS OF THE LEDS USED TO
ILLUMINATE THE WORK BEING EXAMINED.  THE USB LEAD CONNECTING THE MICROSCOPE
TO THE PC HAS A CONTROL BUILT INTO IT TO ADJUST THE INTENSITY OF THE LIGHT.
THE GOOD AND THE BAD THE FIRST QUESTION IS DOES THE MICROSCOPE WORK?  THE
ANSWER IS YES.  IT IS A MICROSCOPE.  IT REVEALS A LOT, PERHAPS MORE THAN
YOU WANT TO KNOW.  HOWEVER, THIS DEVICE MIGHT JUST BE THE TOOL TO FIND A
SOLDER RELATED PROBLEM OR A CUT PC BOARD TRACE.  THE PROBLEM, HOWEVER, IS
‰  END OF 40 WPM TEXT  ‰  QST DE W1AW  ƒ