Table of Contents
Advertisement
FM STEREO
TRANSMITTER
Ramsey Electronics Model No.
Own and operate your own FM Stereo broadcast station.
Definitely not a toy, the FM-10A has an exceptional transmission
range... and the audio quality puts your favorite radio station to
shame. See why this is one of our most popular kits!
•
Great for transmitting your tape deck or CD player throughout the
house, yard or even your car.
•
Powerful enough for college or neighborhood radio stations - in
use all over the world.
•
Fantastic audio quality sounds better than most stations on the
dial. And we'll tell you why!
•
Easily connects to the line-level outputs on any tape deck, stereo
system or CD player.
•
Some users hook up one channel to the scanner and the other to
their two way radio. Now you can hear what's going on around
town up to several blocks away from your house with a simple
stereo receiver... and adjust the volume of each individually with
your balance control!
•
Add a mike-mixer and tape or CD deck for a "PRO" sounding radio
station.
•
Operates on 1.5 to 15 volts, using a crystal controlled subcarrier.
•
Tunable anywhere in the 88-108 MHz FM band.
•
Clear, concise instructions guide you step by step.
FM10A
Advertisement
Table of Contents
Related Manuals for Ramsey Electronics FM10A
Summary of Contents for Ramsey Electronics FM10A
- Page 1 FM STEREO TRANSMITTER Ramsey Electronics Model No. FM10A Own and operate your own FM Stereo broadcast station. Definitely not a toy, the FM-10A has an exceptional transmission range... and the audio quality puts your favorite radio station to shame. See why this is one of our most popular kits! •...
- Page 2 1994 by Ramsey Electronics, Inc. 793 Canning Parkway, 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.
-
Page 3: Table Of Contents
Parts Layout Diagram ..........7 Assembly Instructions ..........8 Choosing an Operating Frequency ......13 Adjusting your FM10A ..........14 Using your FM10A Within the Home ....... 15 Power Supply Considerations ......... 15 LED Power On Indicator .......... 15 Experimental Broadcasting Projects ......16 Antenna Ideas ............ -
Page 4: Introduction To The Fm10A
FM10A is definitely not a toy. We will refer to the FCC regulations frequently in this manual and provide you with some information necessary to enjoy the FM10A's capabilities in accordance with the law. -
Page 5: Fm10A Circuit Description
CIRCUIT DESCRIPTION A quick glance at the Schematic Diagram shows that the custom FM stereo transmitter IC (U1) is at the heart of the FM10A. The control of U1 is determined by its surrounding circuitry. Potentiometers R1 and R4 allow for adjustment of input level. -
Page 6: Parts List
1 38 KHz crystal (small silver cylindrical "can" with 2 small leads), taped to a piece of paper. 1 Shielded inductor coil (L1) (small square silver “can”) 1 Ramsey FM10A Printed circuit board 1 Plastic alignment screwdriver 1 PC board mounted push-button switch 3 RCA-type PC-mount jacks (J1,2,3) 1 2.5 mm phone jack (J4) -
Page 7: Parts Layout Diagram
(included with the Ramsey CFM case and knob set. OPTIONAL Ramsey FM10A case and knob set (CFM), or your own enclosure LED "power on" indicator and 1K resistor Audio switching-mixing accessories of your choice FM10A PARTS LAYOUT DIAGRAM... -
Page 8: Assembly Instructions
When a multi-function IC "chip" is the heart and soul of one of our kits, as is the case in this FM10A stereo transmitter, we try to make a reasonable compromise between following the signal path and... - Page 9 • SOLDER ALL wires or pins of the part, whether the two wires of a resistor or the 18 pins of an IC socket. • Nip or "trim" all excess wires extending beyond each solder connection, taking care that wire trimmings do not become lodged in PC board solder connections.
- Page 10 For use in Europe, Russia and some other countries, use 10K ohm resistors in steps 11 and 12. These resistors set the pre-emphasis characteristics for the FM10A. Pre-emphasis is a technique used in FM transmitters to increase the high frequency signal to noise ratio.
- Page 11 17. Install glass bead diode D1. 18. Install glass bead diode D2. 19. Install glass bead diode D3. 20. Install R7, the small yellow trimmer potentiometer marked "104". 21. Install C19, the 470 µF electrolytic. Be sure to position for correct polarity.
- Page 12 35. Install R10, 10K ohms [brown-black-orange]. The following two capacitors have the identical functions of coupling the RF output from the collector of Q1 to the RF output jack (J3) and also the mounting point provided if you wish to use an on-board whip antenna. 36.
-
Page 13: Choosing An Operating Frequency
"trial" C16 capacitor with a small amount of lead-length to spare, so that it is easy to salvage and replace. This will enable you to properly test your FM10A and then at a later point, you may change C16 as desired. -
Page 14: Adjusting Your Fm10A
"line-level outputs" of a cassette deck or CD player. Most stereo systems have a variety of auxiliary output jacks of which one or more are line-level outputs. Hooking up an audio source to your FM10A is really quite simple. However, there are some general rules: •... -
Page 15: Using Your Fm10A Within The Home
USING THE FM10A WITHIN THE HOME A most practical use for the FM10A would be to connect it to the main stereo system within a large home so that whatever is playing on the main system can also be tuned-in on portable FM radios in other rooms, the garage or out in the yard. -
Page 16: Experimental Broadcasting Projects
2. It would be an excellent class, family or Scout project. 3. Commercially-made stereo mixing consoles, while much less expensive today than a decade ago, will cost much more than did your FM10A kit! 4. The more home-built your complete setup, the more it is in conformity with the spirit of FCC Part 15 regulations. -
Page 17: Antenna Ideas
Companion (STC-1) for a “radio station” quality home broadcasting set-up. ANTENNA IDEAS The simplest, yet very effective, antenna for the FM10A consists of a "dipole", set up either horizontally or vertically, and connected to the transmitter output jack through a few feet of coaxial cable (either RG-58, RG- 59 or miniature RG-174, available at Radio Shack and other sources). -
Page 18: Troubleshooting Guide
If you know how to do correctly, then do so - safely. If not, you can show your FM10A and this book to a licensed radio engineer and negotiate with that person for a safe installation which will feed your signal through interior wiring of your home or building. -
Page 19: Appendix A: Fcc Rules And Information
In the United States, this is how the FCC regards your transmitter kit: Licensed FM broadcast stations and their listeners have ALL the rights! Your use of a device such as the FM10A kit MAY have some limited privileges in locally-unused band space. - Page 20 Part 15.221. Use our AM-1 AM radio broadcast kit for this use. 6. FCC Rule No. 15.239 specifically addresses operation in the 88-108 MHz FM broadcast band for which your FM10A transmitter kit is designed. However, this Rule does not, by itself, tell you everything you need to know about using a device of this kind.
- Page 21 FM stations, this is a "generous" limitation designed to accommodate cruder FM devices. Properly built and adjusted, the FM10A kit operates well within this limit. In fact, its signal should sound no "wider" than any other FM station when listening on an ordinary FM radio.
-
Page 22: Appendix B: Understanding Field-Strength
APPENDIX B: UNDERSTANDING LEGAL "FIELD STRENGTH" A "microvolt" is one-millionth of one volt and designated "µV" in the following explanations. The new FCC Part 15 Rules specify a maximum "Field Strength" of your transmitted signal. Since it is unlikely that you have the equipment to carry out accurate field strength measurements in microvolts, it is useful to understand at least the theory of field strength so that you can understand both what you can expect from such transmitters, and what limits the FCC... - Page 23 DISTANCE FROM TRANSMITTER ANTENNA METERS FEET FIELD TOTAL STRENGTH RECEPTION (µV) AREA 314 FT 1256 FT 4800 FT 19113 FT 1.8 ACRES 7.2 ACRES 28.6 ACRES 1260 11.4 ACRES 2520 458 ACRES 5036 1830 ACRES 1536 broadcast on a school campus, campground or local neighborhood, as long as you do not cause interference to broadcast reception.
-
Page 24: Summary
The present edition of Part 15 of the FCC rules does not provide detailed guidance on ALL aspects of using a low-power transmitter such as the FM10A. The main point is that you may not cause any interference whatsoever to licensed broadcast services and that you must be willing to put up with any interference that you may experience. - Page 25 The radio-frequency "intentional radiator" device which may be constructed from kit parts supplied by us is intended and designed by Ramsey Electronics, Inc. to conform to applicable provisions of Part 15 of FCC Rules. The individual kit-builder and all users of this device assume responsibility for lawful uses conforming to FCC Part 15 Rules.
- Page 26 [1] This device may not cause harmful interference, and [2] this device must accept any interference received, including interference that may cause undesired operation. Final comment A well-informed person will see today's FCC Rules to be evolving and progressively less-restrictive. Even though today's technology is far more complex than what was possible at the time of the Communications Act of 1934, the FCC rules are becoming more relaxed, giving radio experimenters more and more opportunities to explore many frequency bands, using many...
-
Page 27: Fm10A Kit Warranty
But on rare occasions a sour component can slip through. All our kit parts carry the Ramsey Electronics Warranty that they are free from defects for a full ninety (90) days from the date of purchase. Defective parts will be replaced promptly at our expense. If you suspect any part to be defective, please mail it to our factory for testing and replacement. -
Page 28: Canning Parkway Victor, New York
Holder for PC Board/Parts (RS64-2094) • Desoldering Braid (RS-2090) Manual Price Only: $5.00 Ramsey Publication No. MFM10A Assembly and Instruction manual for: RAMSEY MODEL NO. FM10A FM STEREO TRANSMITTER RAMSEY ELECTRONICS, INC. 793 Canning Parkway Victor, New York 14564 Phone...