Ramsey Electronics QRP20 manual Crystal Oscillator Testing, Further Assembly

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CRYSTAL OSCILLATOR TESTING:

◊Connect a key, keyer or momentary switch to J3.

◊Connect +12VDC to power connector J4. Note that the CENTER connection is the positive (+) side.

◊Tune a nearby receiver to the anticipated crystal frequency.

◊Make sure that S1 is set to the correct crystal position.

Keying J3 should result in a crisp, clean oscillator signal in your receiver. Adjusting the R1 tuning control should vary the crystal frequency up to 7 KHz.

If you have installed a second crystal, test it in the same manner. Also, you will notice that the VXO circuit usually swings the frequency down, a fact to remember if you order additional crystals.

NOTE TO NEWCOMERS:Please be aware that even this one transistor oscillator is itself a transmitting device, quite capable in good propagation conditions of emitting an RF signal and HARMONICS, when and if connected to an antenna. It is correct practice to keep your test brief and to identify them with your callsign.

FURTHER ASSEMBLY;

The following three steps connect a simple low-pass filter to the antenna jack. The low-pass filter prevents harmonics from the transmitter from reaching the antenna.

‰37. Install C18, 220 pf (marked 220 or 221).

‰38. Install inductor L6, 1 uh (brown body with wire wrapped around it).

‰39. Install C17, 220 pf (marked 220 or 221).

BUFFER AND RF AMPLIFIER WIRING:

‰40. Install C8, .01 uf (marked .01 or 103 or 10 nf).

‰41. Install Q2, marked 2N3053. Observe the case of transistor Q3. The small metal case tab must be oriented correctly! Please be careful.

‰42. Install R9, 100 ohms (brown-black-brown).

‰43. Install L2, 100 uh [brown-black-brown-silver]

The buffer stage is now completed and connected to the base of the power amplifier stage, Q3.

‰44. Install R10, 270 ohms (red-violet-brown).

‰45. Install L3, 1 uh inductor [brown body with wire wrapped around it].

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Contents CW Transmitter Ramsey Transmitter Kits QRP20 20 Meter CW Transmitter KIT Introduction Watts vs 1 Watt Understanding the Difference QRP-20 WHO should USE a QRP TRANSMITTER? Circuit DescriptionBlock Diagram Parts Supplied with QRP20 Transmitter KIT CapacitorsQRP-20 QRP20 Parts Layout Diagram LEARN-AS-YOU-BUILD Transmitter Assembly Strategy First Assembly StepsQRP-20 Building the VXO Variable Crystal Oscillator Halftime Suggestion Further Assembly Crystal Oscillator TestingBuffer and RF Amplifier Wiring Your Power Supply and RF Output Power Initial TestsVerifying Transmitter RF Output Maximizing RF Power Output TRANS-RECEIVE OperationRamsey Electronics CASE, Knob & Hardware Option Other Enclosure RecommendationsTroubleshooting Guide Final ConsiderationsQRP-20 Ramsey Kit Warranty Ramsey Model NO. QRP20 Meter CW Transmitter KIT

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.
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