Ramsey Electronics FR146 User Manual page 17

73. Install R16, 100K ohms [brown-black-yellow].
74. Install R15, 470K ohms [yellow-violet-yellow].
5. FINAL CONNECTIONS: THE LM386 AUDIO IC STAGE
You now have a working FM receiver ready for adjustment. The output of the
MC3359 FM IC simply needs to be boosted to listening level. A few more
connections, and your receiver will be ready for adjustment and testing! Now
would be a good time to review some of your previous work and also to make
sure you have on hand what you'll need for testing: antenna, fresh battery,
earphone or speaker with correct plug or adapter.
75. Review the instructions for installing U1 and U2. Insert the LM386 IC
(U3) with the band or dot oriented correctly. Solder the 8 connections.
76. Install C32, a 100 to 220 uF electrolytic, observe correct polarity.
77. Install C31, .01 uF (marked .01, 103, or 10 nF).
78. Install C36, 4.7 or 10 uF electrolytic, observe polarity.
79. Install C33, 100 to 220 uF electrolytic, observe polarity.
80. Install the battery snap terminal in the two holes below S1, making
sure that the positive (red) lead is inserted into the (+) hole on the PC
board.
81. The battery bracket may be attached in a variety of ways. A wire
jumper can be passed through the two holes on the PC board, then both
ends soldered on the underside of the board. You may prefer to use very
small screws or even a double-sided mounting adhesive strip or glue. In
using such methods, make sure that the battery will not block the PC
board's mounting hole in its vicinity.
Wiring of the PC board is now complete. If you have the patience, we suggest
a short break. Then take a magnifying lens and a bright light and examine all
your solder joints, touching up any connection which appears less than
perfect. Make sure all excess leads have been trimmed, and that one is not
bent back flat against the board, possibly causing a short. Brush the solder
side of the board with a stiff brush to make sure that no loose wire trimmings
or solder drippings (tsk tsk) are lodged between connections.
FR146 • 17