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Ramsey Electronics SR2 manual

Models: SR2

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jumped ahead and installed T3, we've got bad news for you). Before this shielded transformer can be installed, its internal capacitor needs to be removed. Looking at the underside of this transformer, you'll see a tubular part, probably white with a brown band, somewhat like the resistors in this kit. This is brittle and easily crushed with any sharp object that can be pressed against it with mild force (small nail, nutpick, small screwdriver). You'll find this capacitor will easily disintegrate into particles. DO NOT crush the capacitors in the other two inductors!

ˆ21. After crushing the internal capacitor, install T3. The part fits in the board only one way. Solder all pins.

That completes assembly of the local oscillator section except for two parts. You may notice that we skipped over C15 and C16 while installing the other parts in the area. The reason is that you will have to decide the frequency range you’re trying to receive to know what value capacitors to install. We’ll leave that until the end of the assembly process.

We’ll now move on to the RF section of your SR2 kit. The next few parts form an input filter and mixer section, to combine the RF input with the L.O. section just built. The output of the mixer is the IF, from which we’ll extract the final audio. But let’s not get ahead of ourselves.

ˆ22. Install L1, 1µH inductor [looks like a fat resistor with brown-black- gold bands].

ˆ23. Install L2, the other 1µH inductor [looks like a fat resistor with brown-black-gold bands].

ˆ24. Install C3, .001µF disc capacitor [marked .001, 102, or 1nF].

ˆ25. Install C2, 330 pF disc capacitor [marked 330 or 331].

ˆ26. Install C1, .001µF disc capacitor [marked .001, 102, or 1nF].

ˆ27. Install R13, 1K ohms [brown-black-red]. R13 isn’t part of the RF section but is easier to install now, while we’re in the area.

ˆ28. Install R3, 1K ohm [brown-black-red]. Watch that third color band as red is easily confused with orange!

ˆ29. Install Q1, another of the NPN transistors [marked 3904]. Observe correct orientation of the flat side when placing this part.

ˆ30. Install C10, .1µF ceramic disc capacitor [marked .1 or 104].

ˆ31. Install R12, 1M ohm [brown-black-green]. C10 and R12 are part of the bias circuit for the audio amplifier, U1. Like R13, it is easier to install these parts now.

ˆ32. Install C30, 10pF [marked 10].

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Ramsey Electronics SR2 manual
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SR2 specifications

The Ramsey Electronics SR2 is a versatile and robust RF transmitter designed for a range of applications, including hobbyist projects, educational purposes, and practical uses in the field of amateur radio. Its compact size and user-friendly design make it a popular choice among enthusiasts and professionals alike.

One of the standout features of the SR2 is its frequency range, which typically spans from 88 MHz to 108 MHz. This wide range allows users to operate within the FM band, making it suitable for transmitting audio signals, music, or voice communications. This flexibility is particularly advantageous for those interested in creating their own radio stations or conducting experiments in radio frequency communication.

The SR2 utilizes advanced technology to ensure high-quality transmission. It incorporates modulation techniques that enhance audio clarity and reduce noise, resulting in a smoother listening experience. The transmitter is also equipped with a low distortion audio preamplifier, ensuring that sound quality remains pristine even at higher transmission stages.

Another important characteristic of the SR2 is its ease of assembly. The kit comes with all necessary components, including a printed circuit board (PCB), which simplifies the building process for users. Detailed instructions guide the user through the assembly, making it accessible even for those with limited electronics experience.

The SR2 also boasts a power output of approximately 100 mW, allowing for a transmission range of up to several miles, depending on the surroundings and antenna used. This power level strikes a balance between effective transmission and energy efficiency, catering to various operational settings.

In terms of design, the SR2 features a compact enclosure that protects the internal components from dust and damage, which is vital for maintaining reliability in various environments. Its user-friendly interface includes adjustable controls for tuning and volume, enabling users to customize their transmission settings easily.

Additionally, the SR2 is compatible with a variety of external audio sources, such as microphones, CD players, and smartphones, enhancing its versatility. The unit can be powered by standard power supplies or batteries, making it suitable for both portable and stationary use.

Overall, the Ramsey Electronics SR2 is a well-designed RF transmitter that combines quality, functionality, and ease of use, making it an excellent choice for anyone looking to explore the world of radio transmission.