Advertisement
Trimmer Potentiometers
Mount the four trimmer potentiometers by inserting their
three pins into the holes provided. Press them down
until the "shoulders" of the solder pins are resting
on the surface of the circuit board. Solder all three pins on
each part.
DESIGNATION
VALUE
( ) R5
10k Trimmer
( ) R87
10k Trimmer
( ) R27
1k Trimmer
( ) R58
1k Trimmer
Integrated Circuits
Of all the parts, the ICs are the most easily damaged
and should be treated with some respect. In particular,
they may be destroyed by discharges of static electricity.
Modern ICs are not nearly as sensitive to this kind
of damage as were earlier versions, but it is still good
practice to handle these parts as little as possible.
Also good practice: don't wear nylon during assembly.
Don't shuffle around on the carpet immediately before
assembly (or if you do, touch a lamp or something to
make sure you're discharged). Don't be intimidated.
It's rare for parts to be damaged this way.
ICs are polarized in one or both of two ways; A dot
formed into the case of the IC corresponding to pin 1
or a semicircular notch that indicates the end of the
package with pin 1. Take care that this polarizing
indicator corresponds to the similar indicator on the
circuit board graphics.
The pins of the ICs may be splayed somewhat and not
match the holes in the circuit board exactly. Carefully
re-form the leads if necessary so that they are at right
angles to the part.
Solder each IC in place as it is installed by initially
soldering two pins in diagonal corners of the
pattern. Make sure that the part is seated firmly
against the circuit board by pressing it down while re-
melting the solder joint at first one corner, then
the other. Finally, solder the remaining
connections.
010321
MARKING
CAUTION: Too much solder
here may flow through and
cause problems
Note pin 1
9720 VCO
9
Advertisement
