ˆ50. Install L2, the 14 turn toroid inductor - you marked it special, remember?

ˆ51. Install L3, the remaining 12 turn toroid inductor.

This completes the assembly of your QRP power amplifier. Now's a good time to give your masterpiece a good going over, being especially alert for any:

•bridged-over solder joints;

•misplaced components;

•transistors or diodes placed wrong;

•electrolytic capacitors installed wrong.

INITIAL TESTS:

To prepare your amplifier for testing you'll need the following:

•1. Multimeter capable of measuring voltage and current.

•2. 12 volt DC power source of at least 3 amp capacity.

•3. Suitable dummy load and resonant antenna.

•4. QRP transmitter with a power output in the ½ to 2 watt range, such as the Ramsey QRP-20.

•5. Proper cables to interface between the QRP transmitter and the QRP power amplifier.

With the above all set up and handy, let's get testing!

1.Rotate Bias pot R4 fully CCW.

2.Connect a multimeter to TP1; set the meter to read up to 5 volts DC

3.Connect a dummy load to J1, the amplifier RF output. In a pinch, a light bulb may be used - see the section, "Verifying RF Power Output."

QAMP20 • 12

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Ramsey Electronics QAMP20 manual Initial Tests
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QAMP20 specifications

The Ramsey Electronics QAMP20 is a versatile high-fidelity audio amplifier designed to meet the needs of audio enthusiasts and professionals alike. This compact amplifier is characterized by its exceptional sound quality, robust construction, and user-friendly features, making it suitable for a wide range of applications, from home theater systems to professional audio setups.

One of the standout features of the QAMP20 is its power output. With a maximum output of 20 watts per channel, the amplifier delivers clear and powerful sound, capable of driving a variety of speaker types with ease. The QAMP20 is particularly well-suited for small to medium-sized speakers, providing ample power to enhance the listening experience without distortion, even at higher volumes.

The QAMP20 employs advanced technology to ensure the best possible audio performance. It features a class AB amplifier design, known for its excellent linearity and low distortion. This technology strikes a balance between performance and efficiency, ensuring that users receive high-quality sound while minimizing power consumption. Furthermore, the unit utilizes high-grade components, including capacitors and transistors, which contribute to its overall durability and reliability.

In addition to its impressive audio performance, the QAMP20 boasts a user-friendly interface, making it easy to integrate into any audio setup. It includes multiple input options, allowing users to connect various audio sources, including CD players, computers, and digital music players. The rear panel features standard RCA inputs, while the front includes a 3.5 mm auxiliary jack, providing flexibility and convenience.

Another noteworthy aspect of the QAMP20 is its compact design. The amplifier is lightweight and small enough to fit seamlessly into most setups without taking up much space. This portability makes it an excellent choice for both home and on-the-go applications, allowing users to enjoy high-quality audio wherever they are.

In conclusion, the Ramsey Electronics QAMP20 stands out in the crowded market of audio amplifiers due to its combination of power, advanced technology, and user-centric design. With its ability to deliver exceptional sound quality and its flexible connectivity options, it represents an excellent investment for anyone looking to enhance their audio experience, whether at home or in a professional setting.
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