Ramsey Electronics FM10C User Manual

FM10C 1
FM STEREO
TRANSMITTER
Ramsey Electronics Model No. FM10C
 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/CD deck for a “PRO” sounding station.
 Operates on 5 to 20 volts, using a crystal controlled subcarrier.
 Tunable anywhere in the 88-108 MHz FM band.
Own and operate your own FM Stereo broadcast station.
Definitely not a toy, the FM-10C 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!

Ramsey Electronics FM10C Specifications

General

Frequency Range	88-108 MHz
Modulation Type	FM
Power Supply	12 VDC
Antenna Impedance	50 ohms
Operating Temperature	0°C to 50°C

Summary

Introduction and Overview

Typical Uses for the FM10C

Lists common applications like home stereo extension and listening aids.

Circuit Description

Power Supply and Filtering

Details power input, voltage regulation, and RF filtering.

FM Stereo Transmitter IC (U1)

Explains the BA1404 IC, its functions, and surrounding circuitry.

Audio and Multiplexer Circuits

Covers audio input, filtering, level control, and multiplexer balance.

Stereo Generator and Pilot Signal

Describes the generation of stereo pilot tones and multiplexed audio.

RF Stages

RF Oscillator, Amplifier, and Output

Explains the RF oscillator, amplifier, and output stages.

Parts List

Electronic Components List

Lists all capacitors, inductors, resistors, and semiconductors for the kit.

Component Details

Jacks, Hardware, and External Items

Lists connector jacks, miscellaneous hardware, and required external items.

Assembly Strategy

Assembly Strategy and Tips

Provides guidance on soldering techniques and part installation.

Circuit Board Assembly: Initial Steps

Initial Component Installation

Details sorting parts, correct orientation, and basic installation.

Circuit Board Assembly: Audio Section

Audio Section Component Installation

Instructions for installing inductors, capacitors, and resistors in the audio section.

Circuit Board Assembly: Stereo and Power

Stereo Generator and Power Supply Assembly

Instructions for installing crystal, power components, and capacitors.

Circuit Board Assembly: RF Sections

Multiplexer and RF Oscillator Assembly

Instructions for installing trimmer potentiometers, RF coils, and capacitors.

RF Amp, Output, and Battery Holder Assembly

Instructions for installing transistors, connectors, antenna, and battery holder.

Setup and Adjustment

Frequency Range Selection

Guide for selecting C18 and R8 values for desired transmission frequency.

Choosing an Operating Frequency

Advice on finding clear FM broadcast frequencies to avoid interference.

Case Assembly

Steps for fitting the circuit board and panels into the case.

Adjusting Transmitter Controls

Procedures for tuning frequency, audio levels, and stereo balance.

Using the Transmitter

Practical applications, power options, and LED indicator.

Advanced Topics and Troubleshooting

Experimental Projects and Antennas

Ideas for broadcasting projects and antenna setup.

Antenna Ideas

Suggestions for dipole and ground plane antennas for optimal transmission.

Troubleshooting Guide

Guide to diagnosing and fixing common problems.

Regulatory Compliance

FCC Rules and Information

Summary of FCC rules applicable to FM transmitters.

FCC Rule Details

Details specific rules like bandwidth, frequency limits, and permitted uses.

Understanding Field Strength Limits

Explains the FCC's field strength limits for unlicensed operation.

Field Strength vs. Reception Area

Illustrates reception area based on field strength and distance.

Specifications

FM10C Technical Specifications

Lists technical data including frequency, bandwidth, power, and dimensions.

Warranty and Support

Ramsey Kit Warranty Details

Outlines warranty terms, return policy, repair services, and contact info.

Tools and Items

Required Tools for Assembly

Lists essential tools like soldering iron and cutters.

Suggested Additional Items

Lists recommended items like helping hands and desoldering braid.