background image

AM RADIO KIT

MODEL AM-780K

Assembly and Instruction Manual

Elenco

®

Electronics, Inc.

Copyright © 2007, 1999 by Elenco

®

Electronics, Inc.  All rights reserved.            Revised 2007       REV-F

753108

No part of this book shall be reproduced by any means; electronic, photocopying, or otherwise without written permission from the publisher.

Summary of Contents for AM-780K

Page 1: ...nual Elenco Electronics Inc Copyright 2007 1999 by Elenco Electronics Inc All rights reserved Revised 2007 REV F 753108 No part of this book shall be reproduced by any means electronic photocopying or otherwise without written permission from the publisher ...

Page 2: ...241031 2 C3 C9 047μF Discap 473 244700 3 C4 C5 C8 10μF Electrolytic Radial 271045 2 C6 C7 470μF Electrolytic Radial 284743 SEMICONDUCTORS Qty Symbol Value Description Part 2 D1 D2 1N4148 Semiconductor Silicon Diode 314148 1 IC2 LM 386 Integrated Circuit 330386 1 IC1 484 7642 Integrated Circuit 33K484 MISCELLANEOUS PARTS IDENTIFICATION Qty Description Part 1 Antenna with Holders 484004 1 PC Board 5...

Page 3: ...rst Digit Multiplier Tolerance Note The letter R may be used at times to signify a decimal point as in 3R3 3 3 103K 100V The letter M indicates a tolerance of 20 The letter K indicates a tolerance of 10 The letter J indicates a tolerance of 5 Maximum Working Voltage The value is 10 x 1 000 10 000pF or 01μF 100V Electrolytic capacitors have a positive and a negative electrode The negative lead is i...

Page 4: ...ncy component of the signal leaving a clean audio signal The amount of gain control is varied by potentiometer R3 which also varies the audio level and consequently the volume Capacitor C5 couples the audio signal from the volume control to the input of the audio amplifier Our kit uses the standard design for the audio amplifier on the base of the integral circuit LM 386 To make the LM 386 a more ...

Page 5: ...Solder all components from the copper foil side only Push the soldering iron tip against both the lead and the circuit board foil 2 Apply a small amount of solder to the iron tip This allows the heat to leave the iron and onto the foil Immediately apply solder to the opposite side of the connection away from the iron Allow the heated component and the circuit foil to melt the solder 1 Insufficient...

Page 6: ...e IC socket into place Insert the IC into the socket with the notch in the same direction as the notch on the socket Notch Figure E D1 1N4148 Diode D2 1N4148 Diode see Figure A R4 150Ω 5 1 4W Res brown green brown gold R2 3 3kΩ 5 1 4W Res orange orange red gold IC1 484 7642 IC see Figure B R1 100kΩ 5 1 4W Res brown black yellow gold C1 01μF Discap 103 C3 047μF Discap 473 C5 10μF Electrolytic C4 10...

Page 7: ...ds as shown Fasten C1 into place on the top side of the PC board with two 3 x 5 32 screws Fasten the knob to the shaft of the gang with a screw Solder leads to pads 3 Leads 4 Leads Foil Side Figure G Turn the dial fully clockwise Remove the protective backing from the label and align the 1600 with the arrow on the PC board NOTE SAVE the protective backing from the label for it will be used on page...

Page 8: ...iron The insulation should come off very easily CAUTION The soldering iron will burn the hard surface that you are working on 7 Solder the 4 colored wires to the PC board Wire 1 green to the hole marked 1 Wire 2 red to the hole marked 2 Wire 3 blue to the hole marked 3 Wire 4 white to the hole marked 4 Figure I INSTALL BATTERY HOLDER AND ANTENNA Bend the leads of the battery holder as shown in Fig...

Page 9: ... the ferrite core as shown in Figure L 1 One of the most frequently occurring problems is poor solder connections a Tug slightly on all parts to make sure that they are indeed soldered b All solder connections should be shiny Resolder any that are not c Solder should flow into a smooth puddle rather than a round ball Resolder any connection that has formed into a ball d Have any solder bridges for...

Page 10: ... hear tapping from the speaker check capacitors C3 C4 and C5 and resistor R3 e Short pins 2 and 3 of IC1 several times If you don t hear tapping from the speaker check IC1 R1 R2 R4 R5 D1 D2 and C1 Turn OFF power Remove the short wire from C2 f Check the antenna coils L1 and L2 and capacitor C2 If you have an ohmmeter measure the resistance on the pads of capacitor C2 see Figure N The resistance sh...

Page 11: ...Electrical flow Diode An electronic component that changes alternating current to direct current FM Frequency Modulation Frequency Wave or pulse repetition rate Gain Signal multiplication IC Integrated Circuit PC Board Printed Circuit Board Potentiometer Three terminal variable resistor volume control Power Supply An electronic circuit that produces the necessary power for another circuit Resistor...

Page 12: ...Elenco Electronics Inc 150 Carpenter Avenue Wheeling IL 60090 847 541 3800 Web site www elenco com e mail elenco elenco com ...

Reviews: