ac power

295 links - and 4 categories

Pages: [prev] 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15

Antennas : 40M

40 meters band beverage antenna - The author describes his experience building and using a Beverage antenna for the 40-meter band. Despite encountering some challenges, the antenna offered some improvements in receiving stations compared to a 3-element inverted Vee antenna. The Beverage antenna showed a significant daytime signal-to-noise ratio improvement and received signals better than the Vee antenna. However, the front-to-back ratio was not ideal, and the transmit power seemed to affect the Beverage antenna. Overall, the author concludes that the Beverage antenna might be more suitable for locations with higher noise levels. The total cost of the antenna was around 30 Euros.
[ Hits: 34 | Votes: 0 | Rating: 0 ]

Antennas : End-Fed : End Fed Half Wave Antenna

40m QRO End Fed Half Wave Antenna Coupler - A medium power End Fed Half Wave Antenna coupler, specifically tuned to the QRP frequency of 7030 kHz. Constructed from coil stock and capacitors, it achieves an impedance ratio of 64:1. The coupler has proven effective for power ranges from 2 to 100 Watts on the 40m band.
[ Hits: 104 | Votes: 0 | Rating: 0 ]

Antennas : Wire

Wire on the Ground: Portable Radio Success with Grasswire Antenna - The author shares a unique experiment with a 200ft Grasswire antenna—laying wire directly on the ground. Despite inherent losses, the setup enables successful radio communication with a Kentucky station, highlighting the antenna's practicality for portable use with minimal power.
[ Hits: 103 | Votes: 0 | Rating: 0 ]

Operating Modes : Portable Operations

Hamstick Experimentation: A Day of Surprising Results - In his POTA activation, WK4DS experimented with radials for hamstick antennas. Despite sun and RF noise challenges, successful connections were made. Surprisingly, tuned radials proved unnecessary, simplifying setup. Hamsticks demonstrated versatility across frequencies. Increased power improved signal quality, sparking his curiosity for further exploration in radio technology.
[ Hits: 44 | Votes: 0 | Rating: 0 ]

Operating Modes : QRP

Antennas for QRP Operation - Antennas for low-power operation resemble those for 100W use. Minor adjustments, like capacitor voltage ratings, may apply, but basic principles persist. Portable antennas, notably Backpack Antennas for weight-conscious setups, hold relevance beyond QRP. While some antennas function acceptably at higher power, efficiency issues arise at QRP levels. Testing antennas at 100W exposes weaknesses, particularly in tuners, crucial for efficient QRP operation.
[ Hits: 88 | Votes: 0 | Rating: 0 ]

Radio Equipment : HF Transceivers : Icom IC-705

IC705 GoBox: A Portable Windows-Based Solution for All-Digital Modes - This project details the creation of a portable GoBox housing an IC705, Windows 11 PC, and Bluetooth microphone. The robust setup, enclosed in a weatherproof Hofbauer Explorer Case, ensures stability and functionality for QRP and emergency radio activities. The aluminum-mounted devices minimize RF interference, and a built-in LifePO4 battery powers the 10.1 TFT touch LED monitor, providing approximately 12 hours of use in receive mode. With a focus on grab-and-go versatility, this GoBox stands as an efficient solution for outdoor ham radio operations.
[ Hits: 96 | Votes: 0 | Rating: 0 ]

Radio Equipment : HF Transceivers : Icom IC-706

Icom 706MK2G Repair - After years of reliable performance, a 26-year-old Icom 706MK2G exhibited an unusual deviation during FM transmission, with the actual frequency being 10kHz off from the displayed frequency. Additionally, the power meter showed a sharp dip during transmission. Upon investigation, it was discovered that the FM VCO voltage adjust variable had become dirty and sluggish over time. By adjusting the variable capacitor and cleaning it with switch cleaner, the issue was resolved, restoring stable power output and accurate frequency transmission.
[ Hits: 18 | Votes: 0 | Rating: 0 ]

Radio Equipment : HF Transceivers : Yaesu FT-817

FT-817 Audio Speech Compressor: Boosting Signal Power with SSM2165 - Designed for the FT-817, this audio speech compressor, centered on the Analog Devices SSM2165, offers a 40 dB compression range, enhancing signal power. Built externally with the SMD version to preserve warranty, the circuit interfaces smoothly with electret microphones. Testing shows a 6 dB average power increase. Adaptable to rigs with electret microphones, it maintains unity gain and 40 dB compression.
[ Hits: 60 | Votes: 0 | Rating: 0 ]

Software : Linux : Linux Distributions

DragonOS Focal - DragonOS is a linux distribution dedicate to Software Defined Radio. It leverages the portability, security, and power of Lubuntu Linux as a delivery package and operating environment for a pre-installed suite of the most powerful and accessible open source SDR software. DragonOS has verified support for a range of inexpensive and powerful SDR hardware, including RTL-SDR, HackRF One, LimeSDR, BladeRF, and many others.
[ Hits: 206 | Votes: 0 | Rating: 0 ]

Technical Reference : AI Ham Radio

AI Projections for Ham Radio Modes in 2023-2025 - In an innovative analysis, Michael G7VJR employs NeuralProphet to predict ham radio modes' usage trends. The AI model, leveraging deep learning, forecasts a steady FT8 dominance, with slight declines in CW and Phone activities. This approach simplifies statistical predictions, showcasing the power of AI in understanding complex patterns and facilitating insightful time series projections. Access the freely available Club Log data for continuous exploration.
[ Hits: 55 | Votes: 0 | Rating: 0 ]

Technical Reference : Alternative Power

Reliable Emergency Power: Solar Solutions - In a quest for reliable emergency power, the article discusses the necessity of accessible power solutions amidst blackouts and energy crises. It introduces the American-made Merlin Panther 100-watt solar briefcase and budget-friendly LiFePO4 batteries. The setup addresses the need for modular, renewable power solutions, balancing cost-effectiveness with functionality for various scenarios. The narrative emphasizes the importance of reliable power sources in unpredictable situations.
[ Hits: 48 | Votes: 0 | Rating: 0 ]

Technical Reference : Amplifiers : VHF Amplifiers

50 MHz 300W Power Amplifier - This project addresses the need for a 50 MHz Amplifier providing substantial power for Australian "Advanced Licensees" permitted to use 400W PEP in the 52-54 MHz band. In regions limited to 100W PEP due to TV channel usage, this initiative aims to enhance power output for transceivers with lower capabilities on the 6m band.
[ Hits: 69 | Votes: 0 | Rating: 0 ]

Technical Reference : Antenna Switch

Smart SO2R Antenna Switcher: A DIY Solution - In pursuit of enhanced station efficiency, the author describes crafting an Arduino-based smart antenna switcher for an SO2R setup. Faced with manual antenna switching challenges during contests, the project utilizes a Logos Electromechanical 4x4 Driver Shield and a Power Screw shield for seamless functionality. Despite its raw appearance, the automatic switcher proves indispensable in contest scenarios, prompting considerations for future improvements and standardization of station control protocols.
[ Hits: 153 | Votes: 0 | Rating: 0 ]

Technical Reference : Ham Radio Go Kits

Portable Efficiency: Building a KX3 Go-Box - A Go-box streamlines radio setup for temporary operations. Detailed guidance is provided on constructing a KX3 Go-box based on Radioset-go products. Emphasizing cooling, it incorporates silent fans and a temperature-controlled system. Wiring complexities, power considerations, and battery installation are covered. The Go-box offers a neat solution for field days and temporary setups, improving the efficiency and portability of the Elecraft KX3.
[ Hits: 37 | Votes: 0 | Rating: 0 ]

Technical Reference : LoRa and LoRaWan

LoRa in Amateur Radio - About LoRa, wireless communication technology designed to transmit data over long distances. LoRa provides a means for wireless data transmission over long distances with low power consumption. Practical applications of LoRa in amateur radio
[ Hits: 102 | Votes: 0 | Rating: 0 ]