Vectronics VEC-821K - Manual (Page 18)

VEC-821K Instruction Manual Super CW Filter Kit
• 020. Take another 3" piece of insulated wire and insert one end into the hole
silk-screened SPKR on the circuit board. Solder in place and trim the
excess lead.
•
0 2 1 . L o c a t e t h e b a t t e r y s n a p .
• 022. Insert the RED wire of the battery snap into the hole on the circuit
board labeled, PWR. Solder in place and trim the lead.
• 023. Insert the BLACK wire of the battery snap into t h e h o l e o n t h e
circuit board labeled, GND. Solder in place and trim the lead.
• 024. Locate both LM747 op amp integrated circuits. Insert them into is
sockets for U1 and U2. Please refer to the "Parts Placement" section,
Figure 1 for proper orientation. Be sure not to bend any of the pins
underneath the is body, and that all pins are inserted into the socket.
• 025. Locate the LM380 audio amplifier integrated circuit. Insert it into is
socket for U3. Please refer to the "Parts Placement" section, Figure 1 for
proper orientation. Be sure not to bend any of the pins underneath the is
body, and that all pins are inserted into the socket.
At this point, your kit is finished and it's time to take a well-earned break! You
s h o u l d h a v e o n e w a s h e r a n d n u t l e f t . T h e s e parts are to be used when the
circuit is installed in an enclosure, so do not discard them. When you come
back, be sure to give your work a close "quality control" inspection.
PC Board Inspection:
Before applying power to your kit, give it a thorough QC ( quality control)
inspection. This will help you find inadvertent assembly errors that might
prevent the filter from working or cause damage to sensitive parts. Follow this
procedure:
•
Compare parts locations against the parts -placement diagram. Was each p a rt
installed where it is supposed to be? Was the correct value used? Start at
one side of the board and work your way across in an organized pattern.
•
Inspect the solder side of the board for cold -solder joints and solder bridges
between tracks or pads. Use a magnifying glass to obtain a clear view of
the track area. If you suspect a solder bridge, hold the board in front of a
bright light for a better view. All joints should be smooth and shiny,
indicating good solder wetting and flow. Resolder any beaded or dull-
appearing connections.
If you find a construction error and need to remove a part or two, it will be
easier if you have the right tools. One very convenient item for freeing