❒3. Install J2, the subminiature phone jack. Solder all three points. Be gentle and patient in inserting, so as not to damage the solder tabs.

❒4. Install R13, 5K trimmer pot. This is the modulation adjustment control.

❒5. Install U1, LM358 op-amp IC chip. In installing the IC, you may wish to use an 8-pin DIP socket rather than soldering the IC directly to the board. Reasons for doing this might include the peace of mind of being able to easily replace the IC if ever necessary. However, please be aware that we have seen more service problems with improper socket insertion than from soldering in IC's. Even if this is your first IC, don't be afraid to use enough heat to make 8 clean connections, but DO be sure to orient the end marked by a band or dot correctly. Before soldering, make sure that the IC or socket is perfectly flat against the top of the PC board and that all pins are properly in each PC board hole. This little 8 pin chip contains two separate amplifiers and is used to amplify the microphone output and process the audio for transmisssion.

❒6. Install C39, .001 uf disc capacitor (marked .001, 1 nf or 102).

❒7. Install C38, .001 uf disc capacitor (marked .001, 1 nf or 102).

❒8. Install C36, .01 uf disc capacitor (marked .01 or 10 nf or 103).

❒9. Install R14, 100K ohm (brown-black-yellow).

❒10. Install R18, 100K ohm (brown-black-yellow).

❒11. Install R19, 100K ohm (brown-black-yellow).

❒12. Install C41, .001 uf disc capacitor (marked .001, 1 nf or 102).

❒13. Install R20, 270 ohm (red-violet-brown).

❒14. Install C42, 10 uf electrolytic capacitor. Electrolytic capacitors are polarized with a (+) and a (-) lead and must be installed in the correct orientation. Ordinarily, only the negative side is marked on the capacitor body with a dark band and the (-) sign clearly shown, while PC boards will usually show the (+) hole location. Use care to ensure proper polarity.

❒15. Install JMP2, jumper wire. Use a piece of wire clipped from a previously installed component bent into a small "U" or wire staple shape. Jumpers act as electronic "bridges" carrying signals over PC board traces underneath.

❒16. Install another wire jumper, JMP1.

❒17. Install C34, 10 uf electrolytic capacitor. Remember to observe correct polarity.

❒18. Install C37, .001 uf disc capacitor (marked .001, 1 nf or 102).

❒19. Install R17, 47 K ohm (yellow-violet-orange).

❒20. Install C40, .001 disc capacitor (marked .001, 1 nf or 102).

FT146 • 9

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Ramsey Electronics FT146 manual
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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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