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NOISE REDUCTION ANTENNA
Ramsey Electronics Model No.
Trying to receive distant stations "down in the noise" ?!!
Frustrated by continuous powerline noise or adjacent channel
interference ? Try our signal "magnet" to pull in those weak
stations.
•
Tunes entire AM broadcast band and can also be configured for
any frequency range between 500 KHz to 15 MHz !
•
Stuck for space ? Out performs "long wire" short wave radio
antennas 100 times it size !
•
Features a Faraday shield to eliminate electrostatic noise caused
by powerlines, florescent lamps, or light dimmers - completely
static free reception.
•
Varactor diode tuning ensures precise station tuning - really helps
to pull in those weak stations.
•
Directional properties of the antenna help to "null" overpowering
local stations in order to get that rare station.
•
Low noise, high gain FET preamplifier circuit is housed inside the
antenna assembly, where it's needed most !
•
Rugged antenna enclosure constructed from PVC pipe
"weatherproofs" the ferrite rod antenna assembly, making the
antenna ideal for use indoors or out.
•
E - Z one wire connection from the tuner box to antenna assembly,
can be run up to 500' !
•
Complete and informative instructions guide you to a kit that works
the first time, every time - enhances resale value, too !
SM100
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Table of Contents
Troubleshooting
Related Manuals for Ramsey Electronics Signal Magnet SM100
Summary of Contents for Ramsey Electronics Signal Magnet SM100
- Page 1 NOISE REDUCTION ANTENNA Ramsey Electronics Model No. SM100 Trying to receive distant stations “down in the noise” ?!! Frustrated by continuous powerline noise or adjacent channel interference ? Try our signal “magnet” to pull in those weak stations. • Tunes entire AM broadcast band and can also be configured for any frequency range between 500 KHz to 15 MHz ! •...
- Page 2 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. SM100 • 2...
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Page 3: Table Of Contents
Ramsey Publication No. MSM100 Price $5.00 KIT ASSEMBLY AND INSTRUCTION MANUAL FOR SIGNAL MAGNET NOISE REDUCTION ACTIVE ANTENNA TABLE OF CONTENTS Introduction ........4 SM100 Circuit Description .... 5 Parts list ........6 Parts Layout diagram ....8 Schematic diagram ....... 9 SM100 Assembly instructions .. -
Page 4: Introduction
INTRODUCTION From the earliest days of radio until the present, news, sports, and “talk” radio broadcasts have been transmitted using an (A)mplitude (M)odulated waveform. This type of transmission ensured reliable broadcasts with a large transmission range. In fact, large AM transmitters are used on the shortwave radio bands to send signals around the world! Sounds almost to good to be true? Well, there are a few disadvantages. -
Page 5: Sm100 Circuit Description
electromagnetic waveform is also produced. This waveform is not susceptible to the ravages of electrostatic bursts so it is more desirable to receive. Well, this is exactly the problem we encountered here at Ramsey. While trying to “keep an ear on” the football sports broadcasts 90 miles away, power line noise and low power conditions caused us to string a long wire antenna in hopes of receiving a stronger signal. -
Page 6: Parts List
SM100 PARTS LIST RESISTORS 1 10 ohm [brown-black-black] (R1) 1 75 ohm resistor [violet-green-black] (R14) 3 470 ohm [yellow-violet-brown] (R5, 11, 15) 5 1K ohm [brown-black-red] (R2, 3, 4, 7, 13) 1 8.2K ohm [grey-red-red] (R8) 1 10K ohm [brown-black-orange] (R 9) 2 100K ohm resistors [brown-black-yellow] (R10, 12) 1 1 megohm resistor [brown-black-green] (R16) 5K ohm trimmer potentiometer [marked 502M] (R17) - Page 7 1 9 inch length of RG-174 mini coaxial cable 1 1/2 inch chassis mount “F” connector, with nut and ground lug 2 7 inch lengths of 1 inch diameter PVC pipe. 1 1 inch PVC elbow 1 1 inch PVC endcap with a .375 inch hole drilled in the center 1 1 inch PVC endcap with no hole drilled 1 8 inch length of 1/2 inch PVC pipe 1 12VAC @ 250 mA (or greater) plug in type wall transformer...
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Page 8: Parts Layout Diagram
SM100 • 8... -
Page 9: Schematic Diagram
SM-100 PARTS FINDER DIAGRAM LONG LEAD SM100 • 9... -
Page 10: Parts Layout Diagram
Now, let's get building! First things first. You'll notice that the two circuit boards are connected together. Before we begin building. we’ll need to separate the circuit boards by gently twisting the smaller SM100A circuit board to separate it from the larger SM100C board. - Page 11 6. Install 1N4002 diodes D1 and D2. Notice that the bands do not face in the same direction when installed. 7. Install C1, 220 uf electrolytic capacitor. Electrolytic capacitors are polarized with a (+) and a (-) lead and must be installed in the correct orientation.
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Page 12: Sm100 Assembly Instructions
18. Install R4, 1K ohm (brown- black-red). Leave these leads 19. Install R1, 10 ohm (brown- as long as possible black-black). PC Board 20. Locate and install Q1, a 2N3904 transistor. Transistors have three "legs" and must be mounted correctly. Notice that the part contains a "flat" side with the writing imprinted on it. - Page 13 31. Install Q5, FET marked 2N5485 or MPF102. Make sure that the flat side is facing C13. 32. Install C10, .1 uF capacitor (marked .1 or 104). 33. Install D6, a varactor diode. It looks just like a transistor with only two leads, and is marked MVAM108.
- Page 14 46. Install C12, .01 uF disc capacitor (marked .01 or 103). 47. Install R11, 470 ohm resistor (yellow-violet-brown). 48. Install D7, 12 volt zener diode (grey glass marked 1N759A). A 12 zener diode has no greater than 12 volts across it. This means that there is always 12 volts at the base of Q3 under normal operating conditions.
- Page 15 Wrap another six turns of foil and cut it. You may wish to hold down the foil with a small piece of tape at each end. 56. Using a sharp hobby knife, cut away a strip of aluminum foil the length of the 1/2 inch PVC about 2/10 of an inch wide.
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Page 16: Setup And Testing
63. Carefully push the antenna board into the PVC pipe until only the F type connector extends from the end. Fit the PVC pipe onto the elbow. You can now place the caps on both PVC pipes. Be sure that the one that covers the antenna board has a hole just large enough to allow the connector to pass through. - Page 17 SM100 • 17...
- Page 18 TUNING YOUR SM-100 TO OTHER FREQUENCIES VARACTOR TUNING TURNS TURNS TURNS TURNS VALUE 30 pF 1.67 4.11 13 MHz 350 pF TUNING YOUR SM-100 TO OTHER FREQUENCIES. In order to use your SM-100 on other frequencies, you must wrap the coil differently. Using the table above, and knowing your intended frequency range, pick the correct number of turns for your purposes.
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Page 19: Troubleshooting
Now you are all set to sit back and enjoy your Signal Magnet! We hope that you find it both useful and valuable, both as an educational tool, which you have already benefited from, and a recreational one, which you will enjoy for years. -
Page 20: Troubleshooting
suspect a construction problem on the main board and inspect it for incorrectly placed parts and bad solder joints. Problem: “The antenna doesn't pick anything up, but signals are received through the existing antenna.” Solution: You probably have an faulty wire connection, or a problem on one of the two boards. - Page 21 Problem: “Hey, I don’t own an AM radio!” Solution: We can’t help you with that, but the Signal Magnet does work great with our HR40 40 Meter Receiver Kit! SM100 • 21...
- Page 22 “user friendly” format that is possible. As our customers, we value your opinions, comments, and additions that you would like to see in future publications. Please submit comments or ideas to: Ramsey Electronics Inc. Attn. Hobby Kit Department 590 Fishers Station Drive Victor, NY 14564 techsupport@ramseymail.com...
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Page 23: 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 with the basic kit by Ramsey, please write or call us with information on the part you need and proof of kit purchase. - Page 24 SM100 Signal Magnet Quick Reference Page Guide Introduction ........4 SM100 Circuit Description ..... 5 Parts list ......... 6 Parts Layout diagram ....8 Schematic diagram ......9 SM100 Assembly instructions ..12 Setup and Testing ......19 Troubleshooting ......20 Ramsey kit warranty .....23 REQUIRED TOOLS TOTAL SOLDER POINTS •...
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