Ramsey Electronics FR146, User Manual

Page: 11 / 24

FR146
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11
FURTHER COMPONENT INSTALLATION
All "directions" on the PC board (ie: right, left, above, below and so forth)
assume orientation of your board as shown in the parts layout diagram.
Therefore the rear of the board (connectors) is the lower end, and the front
(controls) is the upper end.
1. ANTENNA INPUT AND TUNED RF PREAMPLIFIER
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5. Install C1, 100 pF disc capacitor.
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6. Install C2, 10 pF.
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7. Install C3, 56 pF.
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8. Install L1, one of the small 1 1/2 turn coils.
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9. Install C4, 56 pF.
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10. Install L2, just like L1 above.
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11. Install C5, 10 pF.
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12. Clearly identify Q1, the 2SC2498 or 2SC2570A transistor. Do not
confuse it with the other transistors supplied. Position Q1 as shown on the
PC board layout, with the flat side facing to the right, toward the middle of
the board. Press the transistor snugly into the PC board so that only a
minimum amount of wire lead is exposed above the board. In soldering,
don't be afraid to use enough heat to make good clean connections.
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13. Install R4, 47K. [yellow-violet-orange] just to the left of Q1.
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14. Install C6, 100 pF. [marked 100, 101, or 101K]
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15. Install R5, 470 ohms. [yellow-violet-brown]
2. SA602 OSCILLATOR-MIXER and VARACTOR TUNING
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16. Install R6, 270 ohms. [red-violet-brown]
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17. Install C7, a .001 uF bypass capacitor. [marked .001, 102, or 1 nF]
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18. In installing the SA602 IC, you may wish to use an 8-pin DIP socket
rather than soldering the IC directly to the board. Reasons for doing this
might include the peace of mind of beginners afraid of damaging the IC, or
experienced builders testing the merits of the SA602's cousin, the SE602.
However, please be aware that we have seen more service problems with
improper socket insertion than from soldering heat damage to IC's. Even if
this is your first IC, don't be afraid to use enough heat to make 8 clean
connections, but DO be sure to correctly orient the end marked by a band,