Ramsey Electronics DDF1, Руководство пользователя

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DDF1
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32. Install U11, the 24 pin 74HC4515 IC. Make sure all the pins pass
through the circuit board before e soldering.
Great job so far! Take a moment now to check your previous solder joints for
“opens” where the solder did not completely flow around the connection or
solder “bridges” between closely spaced pads or IC pins. It seems the best
time to identify these types of problems is now when you’re focused on this
section of the board, saving you time to try to rethink your steps later.
‰ 33. Install R39, 10K ohm (brown-black-orange).
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34. Install R38, 33K ohm (orange-orange-orange).
‰ 35. Install R46, 470 ohm (yellow-violet-brown).
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36. Install C51, .1uF disc (marked 104).
‰ 37. Install R47, 48, and 49, all 470 ohm (yellow-violet-brown).
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38. Install disc capacitors C52, 53, and 54, all .1uF (marked 104).
That concludes most of the digital circuitry included in your kit, take a mo-
ment to recheck your work. We’ll get started now on the audio processing
section of the direction finder kit.
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39. Locate the position of C9 in the upper left hand corner of the main
circuit board. Install C9, .01uF disc capacitor (marked .01 or 103 or
10nF).
‰ 40. Install R23, 220K ohm (red-red-yellow).
‰ 41. Identify D2, the 1N4148 small signal diode (marked with a polarity
band). Use care to orient the part as shown in the parts diagram, and in-
stall in the D2 position.
‰ 42. Install R25, 330 ohm (orange-orange-brown).
‰ 43. Install R24, 10K ohm (brown-black-orange).
‰ 44. Install speaker output jack J4 using the pin connector.
‰ 45. Identify and install Q2, the transistor marked 2N3904. The flat side
must be placed as shown on the PC board, facing R24. Mount it as close
to the board as possible without forcing it. Carefully solder all three
leads.
‰ 46. Identify and install C33, a 10 uF electrolytic capacitor. Remember