Ramsey Electronics FM25B, Сборка и инструкция по эксплуатации

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FM25B
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ˆ 58. Install C6, .047 uF ceramic capacitor (marked .047 or 473).
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59. Install R13, 100k ohms (brown-black-yellow).
ˆ 60. Install Q3, the transistor marked 2N3904. The flat side must be placed
as shown on the PC board. Mount it as close to the board as possible
without forcing it.
ˆ 61. Install Q2, another 2N3904 transistor. If you can’t remember how you
just did it, reread the step above!
ˆ 62. Install L1, the shielded can inductor. It only fits in the board one way;
just be sure to seat it flat on the board before soldering.
ˆ 63. Install C10, 10 µF electrolytic capacitor. Watch polarity when install-
ing.
ˆ 64. Install R15, 270 ohms (red-violet-brown).
ˆ 65. Install R12, 10k ohms (brown-black-orange).
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66. Install C7, the last .1 µF disc capacitor (marked .1 or 104 or 100 nF).
ˆ 67. Install C12, 33 pF ceramic capacitor (marked 33).
ˆ 68. Install C9, the other 33 pF ceramic capacitor (marked 33).
ˆ 69. Install X1, 7.6 MHz crystal (thin shiny rectangle marked 7.600000).
The next group of parts are all the same and all must be oriented the same
way. Be careful with this step! One diode installed backwards will make it im-
possible to transmit on some frequencies while having no effect on others.
Makes for interesting troubleshooting! Don’t worry, hardly anyone messes this
one up so we’re sure you’ll have no trouble installing these parts. Do a double
check before soldering.
ˆ 70. Install diodes D3 through D6, and D9 through D16, all 1N4148 diodes
(small glass diodes). There are 12 installed in this step so you should
have 1 left over when you’re through. Be gentle when bending the leads
down to fit them in the board; these can be fragile. Orient the banded end
as shown on the PC board silkscreen. Solder them all in when you’re sure
they’re oriented correctly.
ˆ 71. Install S3, one of the 8 pin DIP switches. Place the part so that it is flat
to the board and the switches (little white tabs) are toward the outside of
the circuit board. That will place them next to the numbers running along
the outside of the board and they should make it easier for you to tune
your FM25B. Also, if you decide to cut a hole in the side of the enclosure
so that you can reach the DIP switches without taking the cover off, you’ll
be glad they’re placed that way!
ˆ 72. In the same way, install S2. As with the other parts, be sure this one is