Instruction manual

DCI1 16
44. Install R3, a 1K ohm resistor (brown-black-red).
45. Install D10, one of the 1N4148 diodes (small glass diode with black
band). The lead closest to the black band is the Cathode end. Make sure
it lines up with the white band shown on the PC board silkscreen and the
Parts Layout Diagram. Be gentle with this fragile part and double check
the orientation before soldering.
46. Install D3, another 1N4148 diode in the same fashion as D10.
47. Install D11, another 1N4148 diode.
47. Install D2, the last 1N4148 diode.
48. Install Q6, the last 2N3904 transistor. Follow the same guidelines you
did for Q1 through Q4. We’re getting down to the last few parts!
49. Install C5, a .1µF ceramic capacitor (marked .1 or 104). This capacitor
is used to couple the feedback tone back onto the phone line.
50. Install C11, a .1µF ceramic capacitor (marked .1 or 104).
51. Install R9, a 10K ohm resistor (brown-black-orange).
52. Install R10, a 10K ohm resistor (brown-black-orange).
53. Install C15, a .1µF ceramic capacitor (marked .1 or 104).
54. Install C14, a .1µF ceramic capacitor (marked .1 or 104).
55. Install R8, a 10K ohm resistor (brown-black-orange).
With exception of the modular phone jack (J6), you just finished building the
entire DTMF detector circuit! Almost done… just a few more parts to go. Most
of the final few components form the user interface section of the kit.
56. Install R19, a 10K ohm resistor (brown-black-orange).
57. Install R18, a 220 ohm resistor (red-red-brown).
58. Install R11, a 220 ohm resistor (red-red-brown).
59. Install R2, a 10K ohm resistor (brown-black-orange).
60. Install C6, a .01µF ceramic capacitor (marked .01, 103 or 10 nF).
Almost there! Even though you can hardly wait to fire up the kit, take a few
minutes to recheck your assembly up to now. Touch up any solder
connections, recheck all electrolytic/diode/transistor component orientations. A
few minutes now can save time tenfold once you have energized the circuit.
Incorrectly installed parts can be damaged once power is applied.
61. Install pushbutton switch S1 by inserting all six leads through the
circuit board. The switch should fit flat to the circuit board before soldering.