Ramsey Electronics SR2 User Manual

4-19.5 mhz shortwave radio

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4-19.5 MHz
SHORTWAVE RADIO
Ramsey Electronics Model No.
Have you ever wanted to get into the fascinating world of radio?
The Ramsey SR2 is a fine performer that will bring in the world
using just a few feet of wire as an antenna! Folks of all ages
have successfully built and enjoyed this easy and fun kit.
Enjoy hours of fascinating international listening using just a simple
indoor wire antenna
Select portions of the 4 to 19.5 MHz shortwave band, easily re-tuned at
any time
Smooth varactor diode tuning
Excellent sensitivity and selectivity
Front panel Volume and Tuning controls
Multi-stage audio amplifier for room filling volume
Well designed superhetrodyne circuit is easy to build, makes a nice
one-evening project
Ideal scout, school, or club project
Clear, concise step-by-step instructions carefully guide you to a
finished kit that not only works - but you'll also learn too!
Runs on a standard 9 volt battery
Add our matching case and knob set for a finished 'pro' look
SR2

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Summary of Contents for Ramsey Electronics SR2

  • Page 1 Ramsey Electronics Model No. Have you ever wanted to get into the fascinating world of radio? The Ramsey SR2 is a fine performer that will bring in the world using just a few feet of wire as an antenna! Folks of all ages have successfully built and enjoyed this easy and fun kit.
  • Page 2 2001 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. SR2 – 2...
  • Page 3: Table Of Contents

    AND INSTRUCTION MANUAL FOR 4-19.5MHz SHORTWAVE RADIO TABLE OF CONTENTS Introduction to the SR2 ........4 What You Can Expect to Hear ......4 Shortwave Listening as a Hobby ......5 Circuit Description ..........6 Parts Layout Diagram .......... 8 Block Diagram .............
  • Page 4: Introduction To The Sr2

    "null," listening fidelity is less than desirable. WHAT YOU CAN EXPECT TO HEAR First, let's take a look at what is POSSIBLE to hear on your SR2. The following are the international shortwave broadcasting bands within its tuning range: 4.750-5.060 MHz.
  • Page 5: Shortwave Listening As A Hobby

    Reception of CW and SSB signals on an AM receiver requires a BFO. This is not a complicated feature, but it is beyond the purpose of the SR2. Our companion receivers designed for the HAM bands will let you tune into these SSB and CW broadcasts.
  • Page 6: Circuit Description

    HAM radio, CB, antennas, and other topics. To learn more about Ramsey Electronics HAM radio kits, write for our complete catalog. (And, be sure to tell us how you're doing with your SR2 Receiver!) To learn more about the hobby of HAM radio, write ARRL (American Radio Relay League), 225 Main Street, Newington, CT 06111 or visit their website: http://www.arrl.org/.
  • Page 7 Indicator Light Emitting Diode, gives us a general signal level feature. The stronger the signal we receive, the brighter the LED will glow. This is great for help pulling in those weak transglobal transmitter signals. The gain of the SR2 – 7...
  • Page 8: Parts Layout Diagram

    AGC circuit increases the gain of the amplifier (Q2) allowing us to receive signals from around the world and listen to them with clarity. SR2 PARTS LAYOUT DIAGRAM SR2 – 8...
  • Page 9 SR2 – 9...
  • Page 10: Parts List

    1 1N270 diode, glass bead style (D1) 1 Varactor diode, transistor style body with two leads (MVAM108) (D3) 3 NPN transistors, 2N3904 or similar (Q1,2,3) 1 LM358 8-pin DIP IC (U1) 1 LM386 8-pin DIP IC (U2) SR2 – 10...
  • Page 11 1 9-volt battery hold-down clamp REQUIRED, NOT SUPPLIED: 9-volt alkaline or heavy-duty battery Earphone, small speaker, or external amplifier with speaker Antenna or suitable cable, connector, grounding OPTIONAL Ramsey SR2 case and knob set (CSR), or your own enclosure SR2 – 11...
  • Page 12: Assembly Instructions

    3. Install the other 10K PC mount pot, R21. Take care to seat it properly before soldering the 5 pins. 4. Install J1, the RCA jack. You will want to check your placement before soldering and be sure to solder all 4 tabs. SR2 – 12...
  • Page 13 20. Install C21, another .001µF disc capacitor [marked .001, 102, or 1nF]. Before installing T3, the shielded can inductor [marked 42IF123] we must make a modification to the part. It's time for a little "destruction"! (If you SR2 – 13...
  • Page 14 SR2 – 14...
  • Page 15 SR2 – 15...
  • Page 16 We’ll now move on to the RF section of your SR2 kit. The next few parts form an input filter and mixer section, to combine the RF input with the L.O.
  • Page 17 54. Install R10, 1K ohm [brown-black-red]. 55. Install R9, 1K ohm [brown-black-red]. 56. Install T2, the other shielded can inductors [marked 42IF-103]. 57. Install L3, 12 µH inductor [looks like a fat resistor with brown-red- black bands]. SR2 – 17...
  • Page 18 70. Install C13, placing the positive lead in the correct PC board hole. Remember, the banded side indicates the negative lead. • 71. Install the 9-volt battery snap connector, making sure that the red ( + ) black ( - ) leads are inserted correctly. SR2 – 18...
  • Page 19: Shortwave Antenna Ideas

    SHORTWAVE ANTENNA IDEAS The type of antenna you'll want to use for your SR2 depends on the degree of interest you have in shortwave listening, whether you are limited to an indoor or balcony antenna, and whether you think you may soon want to obtain a HAM radio license.
  • Page 20: Initial Testing And Adjustment

    AA-7 may be used with any receiver or even a VHF scanner. It's easy to build and a nice companion for your SR2. If you need more construction details on antennas, check the book mentioned on page 6, or any introductory HAM radio book, or the Radio Shack book on Antennas (No.
  • Page 21 If you are without any kind of testing or frequency reference equipment whatsoever, the easiest way to start enjoying your SR2 is, with the Tune control set at its midpoint, slowly tune T3 with your alignment tool as though it were a tuning dial.
  • Page 22: Troubleshooting Tips

    If you like precision, use a frequency counter or calibrated receiver to find the SR2's strong oscillator signal, remembering that there is a 455 KHz IF difference (above or below) between the local oscillator frequency and the broadcast signal you are hearing.
  • Page 23 THE RAMSEY ELECTRONICS CASE, KNOB & HARDWARE OPTION Your finished receiver can be installed in a variety of enclosures of your own design and choosing. You might be planning to combine several Ramsey circuit kit boards in a single enclosure. Use of the inexpensive and attractive Ramsey case and knob kit will give your unit that finished look and increase its resale value.
  • Page 24 17.67 NEW ZEALAND nx on N Ireland, ID, "Goon Show" 17.67 NEW ZEALAND classical mx, "In Touch with NZ" featuring oldies 17.67 NEW ZEALAND nx, Olympic update, ID's 17.68 CHILE relig pop & inspirational mx, ID's, promos SR2 – 24...
  • Page 25 (MHz) 18.96 SWEDEN "Sweden Today", special on Nobel prizes 18.96 SWEDEN "Sweden Today", article on burden of military spending on developing countries 18.96 SWEDEN Cinema Africa Film Fest being held in Stockholm 18.98 relig mx, sermon, ID SR2 – 25...
  • Page 26 SR2 – 26...
  • Page 27: Ramsey Kit Warranty

    '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 supplied...
  • Page 28 SR2 Shortwave Receiver Quick Reference Page Guide Introduction to the SR2 .......4 What You Can Expect to Hear ....4 Shortwave Listening as a Hobby ..5 Circuit Description .......6 Parts Layout Diagram ......8 Parts List ..........10 Assembly Instructions ......12 Schematic Diagram ......14 Shortwave Antenna Ideas ....20...

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