Ramsey Electronics QAMP20 manual Construction

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In all the following instruction steps, our word "INSTALL" means to do the following:

Insert the part, oriented correctly, into its correct holes in the PC board.

If helpful, gently bend the part’s wire leads or tabs to hold it in place, with the body of the part snugly against the top side (component side) of the PC board.

Solder all wires or pins of the part, whether the 2 wires of a resistor or the 3 or 4 wires of a transistor.

Trim all excess wires extending beyond each solder connection, taking care that wire trimmings do not become lodged in PC board solder connections.

CONSTRUCTION:

Since you may appreciate some "warm-up" soldering practice as well as a chance to put some "landmarks" on the PC board, we'll first install some "hardware" components.

ˆ1. Install S1, PC mount pushbutton switch. Solder all 6 pins securely.

ˆ2. Install J1and J2, PC mount RCA phono jacks. Solder all 4 pins on each securely as these connectors will be subjected to some stress when coax cables are connected to them.

ˆ3. Install J3, PC mount DC power jack.

ˆ4. Install relay K1. Notice that it installs only one way.

ˆ5. Install potentiometer R4. This pot allows adjustment of the bias to the power transistors.

ˆ6. Install C9, .01 µf disc capacitor (marked .01 or 103 or 10 nf).

ˆ7. Install Q5, 221334 PNP transistor, with the flat side oriented toward D2.

ˆ8. Install R6, 470 ohm resistor (yellow-violet-brown).

ˆ9. Install R10, 51 ohm resistor (green-brown-black).

ˆ10. Install R11, 2.2 K ohm resistor (red-red-red).

ˆ11. Install R12, 10 K ohm resistor (brown-black-orange).

ˆ12. Install D2 and D3, 1N4148 style signal diodes (glass body with black band). Pay special attention to the banded ends. The banded end on a diode is the cathode and must be oriented correctly or the circuit will not work. Both diode D3 and diode D2 are detectors for sensing applied RF power.

ˆ13. Install C10, .1 µf disc capacitor (marked .1 or 104).

ˆ14. Install R7, 100 K ohm resistor (brown-black-yellow).

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Contents MTR 20 Watt QRP Linear Amplifier KIT Ramsey Transmitter Kits Meter QRP HOW IT Works IntroductionParts List for the QAMP20 QRP Power Amplifier Capacitors Tips and Notes Ramsey LEARN-AS-YOU-BUILD Assembly StrategyConstruction QAMP20 Transistor bend pix QAMP20 QAMP20 Initial Tests Verifying Transmitter RF Output Your Power Supply and RF Output PowerQAMP20 Troubleshooting Hints Maximizing RF Power OutputEnclosure Recommendations Using the QRP Power AmplifierParts Layout QAMP20 Power Amplifier KIT QAMP20 Ramsey Kit Warranty Total Solder Points Estimated AssemblyQAMP20 20 Watt Linear Amplifier Required Tools

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.