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Ramsey Electronics Model No.
FR1
Build your own FM Broadcast receiver. Radio covers 70 to 110
Mhz, ideal for tuning in out-of-band FM wireless mikes, 'bugs'
and other transmitters that exist where 'others' can't find them!
An added feature of the FR1 is its SCA output, which allows
easy connection of SCA decoders - for commercial -free music,
stock quotes, sports, etc.
Typical uses for the FR1 FM radio receiver:
• Tuning in hidden FM wireless mikes and phone bugs
• Hooking up SCA adapters
• Learning how FM receivers operate
• Snooping around for clandestine transmitters
• Just plain ol' easy listening to the standard FM radio
The Ramsey FR1 FM Broadcast receiver features:
• Runs on 9 volt battery
• Choice of on-board whip antenna or external antenna
• Stable tuning from 70 to 110 Mhz
• Clear, concise step-by-step instructions
• Plenty of speaker volume
• Handy SCA demodulator output
• Lots of helpful hints and hook-ups
FR-1 • 1
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Table of Contents
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Summary of Contents for Ramsey Electronics FR1
- Page 1 Mhz, ideal for tuning in out-of-band FM wireless mikes, ‘bugs’ and other transmitters that exist where ‘others’ can’t find them! An added feature of the FR1 is its SCA output, which allows easy connection of SCA decoders - for commercial -free music, stock quotes, sports, etc.
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Page 2: Fr1 Fm Broadcast Receiver
1994 by Ramsey Electronics, Inc. 590 Fishers Station Drive, Victor, New York 14564. All rights reserved. No portion of this publication may be copied or duplicated without the written permission of Ramsey Electronics, Inc. Printed in the United States of America. FR-1 • 2... -
Page 3: Table Of Contents
KIT ASSEMBLY AND INSTRUCTION MANUAL FOR FR1 FM RADIO RECEIVER KIT TABLE OF CONTENTS Introduction to the FR1 ....4 FR1 Circuit Description ....5 Parts List ........6 Building your kit ......8 Testing and Alignment ....12 Troubleshooting Tips ....14 Other Hook-ups ...... -
Page 4: Introduction To The Fr1
Why you may ask does Ramsey sell a 'plain old FM radio' receiver? No better person to ask than yourself! The FR1; teaches radio theory, allows you to tune outside of the standard broadcast band (great for bugs, FM mikes and other goodies!), has easy hook up for SCA adapters, small size and is just plain fun. -
Page 5: Fr1 Circuit Description
Audio signals from the volume control are amplified to speaker levels by U2, an LM-386 audio amplifier chip. Transistor Q3 provides a buffer stage to external SCA devices you may connect up to the FR1. SCA units decode (demodulate, actually) 'hidden' audio and data services transmitted over standard FM broadcast channels. -
Page 6: Parts List
RAMSEY FR1 FM RADIO RECEIVER KIT PARTS LIST CERAMIC DISC CAPACITORS: 4 .001 uf disc (marked .001 or 102 or 1 nf) [C4,5,15,27] 12 .01 uf disc (marked .01 or 103 or 10 nf) [C2,3,7,8,16,18,20,21,23,24, 28,29] 1 .1 uf disc (marked .1 or 104) [C25] 1 4.7 or 5 pf disc (marked 5 or 5K) [C1]... - Page 7 HARDWARE & MISC: 1 Printed-circuit board 1 9-volt battery hold-down bracket 1 9-volt battery connector 2 RCA-style jack (antenna connector) 1 subminiature earphone jack 1 PC mount pushbutton switch REQUIRED, NOT SUPPLIED: 9-volt battery (alkaline or "heavy duty" type required) Earphone, or small speaker Antenna (whip or wire style) OPTIONAL:...
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Page 8: Building Your Kit
BUILDING YOUR KIT Check off each step as understood and completed. Examine the schematic circuit diagram and PC-board X-ray illustration as you proceed. In all steps, "install" means to insert the correct component in its correct PC board holes, solder properly, and cut or "nip" away any excess wire. Use good soldering technique - let your soldering iron tip heat each connection wire enough so that the wire itself and the foil trace both become hot enough together to melt the applied solder so that it flows smoothly around the wire... - Page 9 13. Install R11, 47K ohm (yellow-violet-orange). 14. Install D1, varactor diode. It has a black body with green and red bands. Observe the correct positioning of the banded end by following the silkscreen. The green band is positioned as shown on the silkscreen. 15.
- Page 10 31. Install C5, .001 uf disc capacitor (marked .001 or 102 or 1 nf). Time for another break. We've now assembled the whole 'front-end' of our receiver. Front-end means the beginning of a receiver up to where it converts to the IF (Intermediate Frequency). 32.
- Page 11 52. Install jumper JMP3. How about another break? Everything is done except for the demodulator section. The front-end is bringing in the signal, the IF amp and filter are amplifying the converted intermediate frequency signal and the audio amplifier is waiting to drive a speaker.
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Page 12: Testing And Alignment
TESTING AND ALIGNMENT A Hex head alignment tool is required to tune up your FR1. If you do not already have a set of plastic or nylon coil alignment tools and expect to build other radio or transmitter type kits, such tools are well worth having and can be found at any electronics store, including Radio Shack. - Page 13 FM broadcast band. RECEIVER SENSITIVITY Your FR1 FM receiver will exhibit sensitivity equal to most standard radio receivers. For the ultimate in sensitivity when using an external antenna, our SA7 broadband preamp is an ideal choice. Or, our AA-7 Active Antenna...
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Page 14: Troubleshooting Tips
SPEAKER SELECTION A fifty-cent' speaker, lying naked on your workbench will not give you a fair test of your FR1 audio quality or volume. Speaker quality and well-designed enclosures have their clear purposes! A reasonable speaker in a box delivers a pleasant listening volume as well as significantly improved fidelity. -
Page 15: Other Hook-Ups
OTHER HOOK-UPS: ALTERNATE POWER SOURCES Most of the FR1 circuitry can be operated from 6 to 14 volts without damage or significant modification. However, it is quite important that you carefully hook up with the correct polarity - reverse polarity or excessive voltages WILL damage your kit. -
Page 16: Sca Output
Your FR1 was designed for clean, undistorted audio from average FM broadcast stations, while keeping battery current drain low. You may significantly increase the FR1’s audio output by adding a single 10 uf electrolytic capacitor across pins 1 and 8 on the LM-386 audio amplifier IC. - Page 17 IN CLOSING... Finally, we remind you that modifications of the kit put you on your own, voiding your Ramsey limited warranty, making your unit ineligible for factory repair. Make sure the receiver is working properly and that you understand how to use and repair it BEFORE making any changes in the original design.
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Page 18: Schematic Diagram
FR-1 • 18... - Page 19 '1K ohm' resistors are actually the 'missing' 10 K parts ("Hum-m-m, I guess the 'red' band really does look orange!") Ramsey Electronics project kits are packed with pride in the USA. If you believe we packed an incorrect part or omitted a part clearly indicated in your assembly manual as...
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Page 20: Ramsey Kit Warranty
ESTIMATED ASSEMBLY Ramsey Publication No. MFR1 TIME Assembly and Instruction manual for: Beginner ....6 hrs RAMSEY MODEL NO. FR1 FM BROADCAST Intermediate ..3.4 hrs RADIO RECEIVER KIT Advanced ..... 2.6 hrs RAMSEY ELECTRONICS, INC. 590 Fishers Station Drive...