Q. I don't have a 12-volt DC power supply for those Progress
Tests outlined in this manual. The cheapest one at Radio Shack™
is $30 what do I do? A. The very cheapest solution is to hook
up to a car battery, but we'll assume you wish to provide the 8
"C" cells accommodated by your receiver's go-anywhere design:
if so, the battery holder/shelf/snap connector assembly detailed
in Steps 7-2 ff. will provide 12VDC as needed for this project.
Q. What is the most important single procedure in the whole
building process? A. Double-checking completed phases, step
by step, for correct parts selection and orientation.
Q. Which kit-builders tend to make the most mistakes?
A. Typically, professional technicians and experienced do-it-
your-selfers, who ARE very good with electronics, may not have
the patience to follow the steady pace of complete part-by-part
directions. What to do seems so obvious to them that they
"stuff the board" very quickly, and then they need to spend lots
more time tracing just one or two little but critical mistakes. This
is common in most hobbies and crafts.
Before Soldering ANY Parts:
You will want to do some kind of sorting and grouping of the kit
parts to make them easier to find. ln particular, be sure to
separate the 9 molded inductors from the 21 1/4-watt resistors.
The inductors have a blue-green background and are slightly
fatter and shorter than the resistors. They also have a very low
resistance (one ohm or less) if measured with your ohmmeter.
Our 1/4-watt resistors normally have a tan background color,
though NOT always! The main possibility for confusion occurs
with R18 and R23, both 3.3 ohms, and L6, 3.3 microhenries, all
with the same color code of orange-orange-gold-gold! R18 and
R23 are installed early in Phase 1.0; simply keep L6 with the
other inductors until they are installed all together.
1253 - 18
PHASE 1
Audio Amplifier Section
1-1a. Carefully identify C12, a .1 μF mylar film capacitor.
It is marked 104 and has a dark, shiny somewhat rectangular
body, quite different from the many ceramic disc capacitors also
used in the kit.
1-1b. Install mylar film capacitor C12 per 1-1a.
1-2. Install C15, also .1 μF and marked 104, but is a ceramic
disc type.
1-3. Install C13, 100 pF, marked 101.
1-4. Install C19, .01 μF, ceramic disc type marked 103.
1-5. Install C9, also .01 μF ceramic disc.
Before soldering any of the following resistors, make certain that
you have selected the correct value. Pay close attention to the
color of the third multiplier band, so that you don't confuse 470,
4.7K and 47 K, etc. Also don't confuse R18 or R23 with L6 --
see note on previous page. Identify and install the following
resistors:
1-6. Resistor R23, 3.3 ohms (orange-orange-gold)
1-7. Resistor R18, also 3.3 ohms.
1-8. Resistor R14, 270 ohms (red-violet-brown)
1 -9. Resistor R16, 470 ohms (yellow-violet-brown)
1-10. Resistor R11, 4.7K (yellow-violet-red)
1-11. Resistor R12, 47 K (yellow-violet-orange)
1-12. Resistor R10, 1K (brown-black-red)
1-13. Resistor R13, 10K (brown-black-orange)
1-14. Identify correctly and insert Q4, transistor type
2N4124G, into its position, making sure that its flat side is
oriented per the board outline. Press the transistor as far into its
holes as it reasonably will go and solder all three connections.
1-15. Examine electrolytic capacitor C17, 220 μF. Notice
that one wire is longer: this is the (+) side. The (-) side is
marked by the dark band stripe down the side of the capacitor.
This and all other electrolytic capacitors in the kit MUST be
installed with the (+) side corresponding to the "+" marked on
the board.
1-16. Install C17, 220 μF electrolytic, per Step 1-15.
1253 - 19
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