Further alignment now consists of adjusting the oscillator coil L3 to permit the tuning control (R1) to cover the 5 MHz. segment between 135 and 175 MHz of primary interest to you. Assuming you wish to adjust for the Two Meter 144-148 MHz Amateur Band, adjust L3 until you hear your intended test signal.

If you are a beginner with no license or other equipment, any Ham operator with a 2-meter transceiver should be willing to give you the test signal and extra help that you need. The FR146 is very sensitive, so operate the transceiver on low power on a simplex frequency from a distance of at least across the room. An 8" piece of wire will be a sufficient receiving antenna for such tests. If you don't know any Hams, visit a friendly two-way radio service center to get close to the test signal you need!

RECEIVER SENSITIVITY

Your FM receiver features sensitivity under 1 uv. Radio Hams constantly marvel at how an FR146 displayed at hamfests tunes in dozens of hand-held QSO's on the premises without an antenna connected! You can expect to monitor local repeater and simplex transmissions easily, using a simple groundplane style antenna. The receiver also responds very well to the addition of a low-noise pre- amplifier such as the Ramsey SA-7/PR-2. For 2 meters, the Ramsey PR-10, with its high-Q tuned circuitry and exceptional signal-to-noise ratio, offers significant performance improvement. A new and versatile receiver accessory is the Ramsey AA-7 HF-VHF Active Antenna, which doubles as a preamplifier with other antennas in addition to the excellent performance of its own whip.

ADDING AN LED POWER "ON" INDICATOR

For many people, a pilot lamp to indicate "power on" is more than a nice touch. They expect it and depend on it, reminding us that "real radios glow in the dark!" Adding a simple LED power-on indicator to your Ramsey kit receiver is easy. All you need is the LED itself and a small 1K to 2.2K resistor.

Study the PC traces between the positive battery supply wire and the on-off switch. The unused connectors on top of your switch are an ideal point to get the

+DC voltage needed for the anode (longer lead) of the LED. Plan where and how you wish to install the LED in your enclosure.

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Ramsey Electronics FR146 manual Receiver Sensitivity, Adding AN LED Power on Indicator
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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.
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