AUTO-SCAN FM RADIO KIT MODEL FM-88K ELENCO® 150 Carpenter Avenue Wheeling, IL 60090 (847) 541-3800 Website: www.elenco.com e-mail: elenco@elenco.com To see our complete line of Educational Products go to WWW.ELENCO.COM Assembly and Instruction Manual ELENCO ® Copyright © 2011 by ELENCO® All rights reserved. No part of this book shall be reproduced by any means; electronic, photocopying, or otherwise without written permission from the publisher.
PARTS LIST GLOSSARY (Continued) If you are a student, and any parts are missing or damaged, please see instructor or bookstore. If you purchased this kit from a distributor, catalog, etc., please contact ELENCO® (address/phone/e-mail is at the back of this manual) for additional assistance, if needed. DO NOT contact your place of purchase as they will not be able to help you. RF Radio Frequency. Sensitivity The ability of a receiver to pick up low-amplitude signals.
PARTS IDENTIFICATION TROUBLESHOOTING Contact ELENCO if you have any problems. DO NOT contact your place of purchase as they will not be able to help you. ® r d) Have any solder bridges formed? A solder bridge may occur if you accidentally touch an adjacent foil by using too much solder or by dragging the soldering iron across adjacent foils. Break the bridge with your soldering iron. 1. One of the most frequently occurring problems is poor solder connections.
TESTING - SECTION 2 You Will Need: • 9V Battery • 25 or 30 watt Soldering Iron • Small Phillips and Slotted Screwdrivers • Long Nose Plier • Side Cutters Voltage reference chart for U1 TDA 7088T (turn radio on and press reset). Test IDENTIFYING RESISTOR VALUES Verify that FM signals are present in your location by listening to another FM radio placed near the FM-88K. Use the following information as a guide in properly identifying the value of resistors.
DESCRIPTION AND FEATURES SECTION 2 ASSEMBLE COMPONENTS TO THE PC BOARD Place a check mark in the box provided next to each step to indicate that the step is completed. C5 - 220pF Discap (221 or 220) S1 - Push button switch S1 - Cap yellow (see Figure J) R4 - 10kΩ 5% 1/4W Res. (brown-black-orange-gold) The ELENCO® FM-88K Kit is a monophonic, two-IC, FM (frequency modulation) receiver designed to receive FM signals in the frequency range (88-108MHz).
TESTING - SECTION 1 a class B amplifier (transistor on for ½ cycle), the maximum theoretical efficiency is 0.785 or 78.5%. Since transistor characteristics are not ideal in a pure class B amplifier, the transistors will introduce crossover distortion. This is due to the non-linear transfer curve near zero current or cutoff. This type distortion is shown in Figure 1.
ASSEMBLE COMPONENTS TO THE PC BOARD Place a check mark transferred through resistor R3 to the anode of the varactor diode D1 (BB910), causing its capacitance to decrease. Decreasing the capacitance of D1 increases the frequency of the local Oscillator (VCO). in the box provided next to each step to indicate that the step is completed. The Oscillator voltage and signals of all the other FM stations (Fs) from pin 11 are inputted into the Mixer.
CONSTRUCTION SECTION 1 • Turn off iron when not in use or reduce temperature setting when using a soldering station. Introduction The most important factor in assembling your FM-88K Auto-scan FM Radio Kit is good soldering techniques. Using the proper soldering iron is of prime importance. A small pencil type soldering iron of 25 - 40 watts is recommended. The tip of the iron must be kept clean at all times and well-tinned.
