QRP-20 | Ramsey Electronics QRP20 specs

5. Insert and solder R1, the 10K tuning potentiometer.

6. Insert and solder S1, pushbutton switch.

Carefully select, insert and solder the following components in the order given in the following steps. Check off each step as completed.

7. C16, 100 to 220 uf electrolytic. Electrolytic capacitors are polarized, which means there is a right and a wrong way to install them! Generally, the Negative ( - ) side is indicated on the capacitor, while the Positive ( + ) is shown on the PC board. Make sure that the capacitor is inserted correctly into the PC board with the ( + ) lead into the ( + ) hole and the ( - ) lead into the ( - ) hole.

8. R11, 100 ohm [brown-black-brown].

9. C19, .01 uf (marked .01 or 103 or 10 nf).

10. D2, 1N4148 diode. This diode is the small glass bead type, do not confuse with D1, the 1N4002, which is larger in size. For correct polarity, the dark band must face as shown on the parts layout diagram.

11. C10, .01 uf (marked .01 or 103 or 10 nf).

The preceding parts comprise much of the circuitry which blocks RF from the receiver during transmission and permits the antenna to be connected to the receiver jack during "key-up" conditions. To further complete this section of the circuit, we now install the first of three 100 uh RF chokes. They look like a resistor with brown-black-brown-silver (or gold) bands. In the following steps, be sure to save the clipped-off component lead wires from R12 and R13. These will be used for "jumpers" in later steps.

12. Install L5, 100 uh inductor [brown-black-brown-silver].

13. Install R12, 1K resistor [brown-black-red].

14. Install R13, 1K resistor [brown-black-red].

15. Using a scrap component lead wire, install JMP1. Jumper wires simply connect two PC board traces together, jumping over other traces!

Next study the orientation of Q4, the keying transistor. Be careful in identifying Q4; it is the only PNP device, and its part number or case style may vary slightly. If necessary, positively identify Q1, the 2N3904 oscillator transistor, and set it aside, since Q4 is similar or identical in style. Proceed with the following steps, in order, once you are positive you have selected Q4 as the 221-334 PNP transistor.

16. Install R15, 10K ohms [brown-black-orange].

17. Install C13, .01 uf (marked .01 or 103 or 10 nf).

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QRP20 specifications

The Ramsey Electronics QRP20 is a compact and innovative low-power transceiver designed for amateur radio enthusiasts who appreciate both portability and efficiency in their operations. This QRP (low power) radio is primarily aimed at those who seek to operate on the HF bands, providing an exhilarating experience for operators who thrive on the challenges and satisfaction of making contacts with minimal power output.

One of the standout features of the QRP20 is its compact design. This radio can easily fit into a backpack, making it ideal for field operation, portable use, or emergency communication scenarios. Weighing in at just a few pounds, it’s lightweight enough for extended outings without burdening the operator.

The QRP20 operates on a range of HF bands, specifically covering 20 meters, which is especially popular among amateur radio operators for its relatively consistent propagation and activity level. The transceiver leverages solid-state technology, ensuring reliability and optimizing performance. It can produce an output of up to 5 watts, which is standard for QRP operations, allowing operators to experiment with different antenna configurations and propagation techniques.

Another significant aspect of the QRP20 is its user-friendly interface. The radio features a straightforward layout with well-placed knobs and buttons for efficient tuning and operation. The built-in digital display provides clear visibility of frequency information and operational status, enhancing the overall user experience. In addition, the QRP20 includes a narrow bandwidth filter, which effectively reduces noise and enhances signal clarity, enabling clearer communication even in crowded band conditions.

The QRP20 is equipped with an internal speaker as well as a headphone jack for private listening. It also features a built-in keyer for CW (Continuous Wave) operation, making it versatile for various modes of amateur communication including voice and Morse code.

Powering the QRP20 is effortless, as it can be run off a standard 12V power supply or a rechargeable battery, giving operators flexibility in power sourcing. Whether during portable activations or in a home setup, the QRP20 is adaptable to different operating situations.

In conclusion, the Ramsey Electronics QRP20 is a remarkable choice for amateur radio users who value portability, versatility, and performance. Its efficient design, solid technology, and ease of use make it a compelling addition to any operator's gear, offering a satisfying QRP experience while staying connected with a global community of radio enthusiasts.