Solder side of
board
Component side of
b d
Solder can to PC
board

❒97. Install D4, 1N4148 style signal diode (glass body with black band). Observe correct orientation of the banded end.

❒98. Install TP3, the last test point. Select a 1K resistor, R29 (brown-black- red). Trim back one lead wire to a length of inch. Bend this wire into a small loop as before. Insert the resistor into the PC board and hold it carefully while you solder it to the board.

❒99. Install R22, 1K ohm (brown-black-red).

❒100. Install C15, 39 pf disc capacitor (marked 39 or 39K).

❒101. Install L4, 2 turn coil wound previously. Be sure it sits flush against the PC board.

❒102. Install C14, 56 pf disc capacitor (marked 56 or 56K).

❒103. Install L3, another 2 turn coil. Be sure it sits flush against the PC board.

❒104. Install C13, 39 pf disc capacitor (marked 39 or 39K).

❒105. Install C7, .001 uf disc capacitor (marked .001 or 1000 or 102).

❒106. Install C12, trimmer capacitor (black body with orange top).

❒107. Install L2, 1 turn coil wound previously. Ensure it sits flush.

❒108. Install L1, 6 hole ferrite bead RF choke you wound.

❒109. Install C1, .01 uf disc capacitor (marked .01 or 103 or 10 nf).

❒110. Locate Q6, SD1127 RF power transistor. This transistor mounts somewhat differently from all the other parts. Turn over the PC board and set the transistor snugly into the large hole and bend the leads over and into the indicated holes. The leads should be as short as possible without shorting against the transistor case. Solder the three transistor leads. See drawing in the step below.

❒111. Now we call for something unusual - soldering the transistor case to the PC board. Run a neat "flow" of solder around the transistor case to the PC

board ground plane. The SD1127 power transistor is designed by

the manufacturer to be soldered directly to a PC board ground

plane for heat sinking and proper

VHF performance. This part is different from other metal can transistors in that the case is connected internally to the emitter rather than the collector. This provides much higher gain at VHF frequencies.

FT146 • 17

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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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