Ramsey Electronics FT146 manual Other Enclosure Recommendations, Crystal Requirements

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Here's a handy reference chart for the 5 pin DIN jack

PIN #

FUNCTION

1

+12 VDC power input

2

Power ground

3

Audio input

4

Audio ground

5

PTT (Push-To-Talk)

Audio level required is in the 10 to 50 mV range. PTT requires a path to ground of less than 10K ohms.

OTHER ENCLOSURE RECOMMENDATIONS

Your finished transmitter can be installed in a variety of enclosures of your own design and choosing. You might be planning to combine several Ramsey circuit boards in a single enclosure. Use of the inexpensive and attractive Ramsey case set will give your unit that finished look and increase its resale value. These sturdy black instrument cases are supplied with neatly-lettered front and rear panels, rubber feet and mounting screws.

While we believe that the Ramsey enclosure option is a fine value for finishing off your Ramsey kit transmitter, we're happy to give you a couple of additional suggestions and our reasons for them. If your first goal is economy and rugged portability, you will find that the circuit board can be mounted nicely in a standard VHS videotape storage box, which also gives room for additional microphone, power and antenna connectors, and even a small mike. The connectors are easily mounted at one end of such a box. It may be necessary to cut away the molded posts which secure the tape cassette itself. These storage boxes come in several styles, so pick one that looks truly practical as a project enclosure.

If you wish to accomplish RF shielding, the most economical metal enclosure nicely suited for Ramsey amateur kit boards is Radio Shack No. 270-253A. This metal utility cabinet can accommodate both a receiver and transmitter board, plus speaker, with room for various refinements you might like to add.

CRYSTAL REQUIREMENTS

The FT146 transmitter uses a crystal at 1/9 the final carrier output frequency. This is a fairly common type of crystal that is found in many of the older "rock- bound" rigs that populate many hamfest flea market tables. You may order additional crystals from JAN Crystal, 1-800-JAN-XTAL, specify HC-18/U holder, wire leads, parallel resonant, 18 pf load capacitance.

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Contents Meter FM 5 Watt Transmitter KIT Ramsey Transmitter Kits FT146 FM Receiver KIT Introduction FT146 Circuit Description FT146 2 Meter FM Transmitter KIT Parts List CapacitorsResistors and potentiometers Inductors and ferrite cores Semiconductor devicesSpecial components Required, not suppliedRamsey Learn-As-You-Build KIT Assembly FT146 FT146 FT146 Test point loop ResistoPC board Winding L3 and L4 Use the same wire Procedure as used above for these coils. Each coilEnameled wire Is 2 1/2 turns and will appear to be 3 turns ifFT146 FT146 Wire jumper Wire sits flat FT146 TESTING, Alignment and Adjustment Short lead hereFT146 Your Power Supply and RF Output Power Verifying Transmitter RF OutputFT146 Maximizing RF Power Output Troubleshooting HintsMicrophone Considerations Other Enclosure Recommendations Crystal RequirementsFT146 FT146 Parts Layout Diagram Ramsey Kit Warranty Estimated Assembly Required ToolsTotal Solder Points Time

FT146 specifications

The Ramsey Electronics FT146 is a versatile and compact FM transmitter that stands out for its user-friendly operation and impressive performance in both amateur and professional audio applications. Designed for hobbyists, educators, and small businesses alike, the FT146 offers a reliable solution for broadcasting audio signals over a short to moderate range.

One of the main features of the FT146 is its simple plug-and-play setup, which allows users to get started quickly without needing extensive technical knowledge. The device operates with a frequency range of 88.1 to 107.9 MHz, covering the entire FM broadcast band. This flexibility enables users to choose the best frequency for minimal interference in their transmission area. Additionally, with an adjustable output power of up to 2 watts, the FT146 can effectively cover distances ranging from a few hundred feet to several miles, making it ideal for a variety of broadcasting scenarios.

The FT146 utilizes advanced modulation technology to ensure high-quality audio transmission. It supports monophonic audio, which is perfect for clear voice and music transmission. The integrated audio limiter prevents distortion, ensuring that the sound quality remains consistent, even at higher volumes or varying audio signals.

Another notable characteristic of the FT146 is its robust construction. Housed in a durable metal enclosure, the transmitter is built to withstand everyday use. The compact design allows for easy portability, making it suitable for field applications, on-location broadcasting, or as a permanent installation in a small venue.

In terms of connectivity, the FT146 features multiple audio input options, including a 3.5mm jack and RCA inputs. This versatility allows users to connect various audio sources, such as MP3 players, computers, or professional-grade audio equipment.

Furthermore, the FT146 also includes an LED power indicator and a built-in antenna output for enhanced transmission efficiency. Users can either connect an external antenna for increased range or utilize the included telescopic antenna for convenience.

Overall, the Ramsey Electronics FT146 combines ease of use with professional-grade features, making it an excellent choice for anyone looking to explore FM broadcasting. Whether for personal projects, educational purposes, or small business promotions, the FT146 delivers reliable performance and adaptability in a compact package.
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