Progress Summary

So far, you have wired the tuned input from the antenna, the RF preamplifier, and the SA602 mixer-oscillator, including the varactor tuning circuit. The work you have done has actually formed a simple receiver capable of tuning in VHF signals of all kinds and converting them to a low-level 10.7 MHz output to be amplified by Q2. This is a good time to review the steps completed to this point before proceeding. Due to the many functions of the MC3359 FM receiver IC, further assembly steps will be in the order of easiest parts installation.

3.TRANSISTOR COUPLING & AFC CIRCUITS, VOLUME & SQUELCH CONTROLS

❒36. Install Q2, a 2N3904 transistor. Correctly position the flat side.

❒37. Install R13, 47K ohms (yellow-violet-orange).

❒38. Install C20, .001 uf (marked .001 or 102).

❒39. Install R12, 1K ohms (brown-black-red).

❒40. Install Q3, 2N3904 transistor.

❒41. Install R10, 1 megohm (brown-black-green).

❒42. Install R11, 1K ohms (brown-black-red).

❒43. Install R22, 2 ohms (red-black-gold).

❒44. Install C29, .01 uf (marked .01 or 103 or 10nf).

❒45. Install C30, 10 uf electrolytic, observe correct polarity.

❒46. Install R18, 18K ohms. (brown-gray-orange).

❒47. Install C28, .01 uf (marked .01, 103, or 10nf).

❒48. Install R19, 10k ohms (brown-black-orange).

❒49. Install jumper wire, JMP2.

❒50. Install C34, .1 uf (marked .1 or 104).

❒51. Install R21, 47K ohms (yellow-violet-orange).

❒52. Install C35, 100 to 220 uf electrolytic, observe polarity.

❒53. Install R20, 270 ohms (red violet-brown).

❒54. Install Q4, 2N3904 transistor.

FR146 • 15

FR146 specifications

The Ramsey Electronics FR146 is a versatile RF transmitter that has gained popularity among hobbyists and professionals alike for its reliability and performance. This compact and efficient device operates in the 146 MHz frequency range, making it suitable for various applications, including remote control systems, wireless audio, and telemetry. Its lightweight design and user-friendly interface make it an excellent choice for both beginners and seasoned RF enthusiasts.

One of the standout features of the FR146 is its ability to deliver a stable and clean signal. It employs advanced modulation techniques to ensure high-quality transmissions, minimizing interference and distortion. The device supports AM modulation, which is ideal for long-range communication due to its excellent propagation characteristics. This feature is particularly useful in outdoor environments where signals can travel considerable distances.

Another significant advantage of the FR146 is its user-adjustable output power. Users can easily modify the transmitter's power settings to suit specific needs, whether they require low power for short-range applications or higher power for extended reach. This flexibility allows for greater versatility in operation and makes it suitable for various scenarios.

The FR146 also comes equipped with a built-in tone generator, which can be used to encode audio signals. This feature allows for the integration of sound with the RF transmission, making it a perfect choice for projects that require audio broadcasting. Furthermore, the device includes a frequency stabilization circuit, ensuring that the transmitter maintains a consistent frequency even under varying temperature and voltage conditions.

In terms of construction, the FR146 is designed for durability and ease of use. It features a robust enclosure that protects the internal components from environmental factors. The device is straightforward to set up, often requiring only a few simple connections for operation. Its lightweight design enables easy mobility, making it suitable for portable applications.

Overall, the Ramsey Electronics FR146 stands out for its combination of advanced features, robust performance, and ease of use. Whether you are working on a personal project, conducting experiments, or managing professional tasks, the FR146 offers a reliable and effective solution for your RF transmission needs. Its adaptability across different applications makes it a valuable addition to any electronics enthusiast's toolkit.