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I built a homebrew 75 meter Double Extended Zepp Antenna, And I needed a 4:1 Balun So I decided to Homebrew the Balun also. Here is how I did it!

Alinco is a prominent manufacturer in the amateur radio industry, specializing in a variety of transceivers, receivers, and accessories. Their product line includes HF radios, mobile transceivers, VHF/UHF handhelds, and scanners, catering to both novice and experienced operators. Alinco's commitment to quality is reflected in their ISO9002/140001 certification, ensuring that their products meet high standards of performance and reliability. In addition to transceivers, Alinco provides power supplies and various accessories that enhance the ham radio experience. Their offerings are designed to support a wide range of operating conditions, making them suitable for both portable and fixed station setups. With a focus on innovation and customer satisfaction, Alinco continues to be a trusted name among amateur radio enthusiasts worldwide.

This homebrew legal-limit antenna tuner is based on the famous "Ultimate Transmatch" introduced by the late Lew McCoy, W1ICP. The Ultimate Transmatch was described in the "Beginner and Novice" section of the July 1970 QST (Page 24).

Arrl document about invisible antennas and indoor systems. It is important to consider that few compromise antennas are capable of delivering the performance one can expect from the full-size variety. But the patient and skillful operator can often do as well as some fellows who are equipped with high power and full-size antennas. The "cliff-dweller" may not be able to "bore a hole" in the band as often, and as easily, but DX can be worked successfully when band conditions are suitable.

This resource provides a historical listing of **unlicensed amateur radio beacons** active in the United States as of December 1993, specifically detailing both **LOWFER** (Low Frequency Experimental Radio) and **MEDFER** (Medium Frequency Experimental Radio) operations. The data includes beacon frequencies in kilocycles (Kc), identification codes, state locations, and the callsigns or names of the beacon operators. Frequencies range from 166.667 Kc for LOWFER to 1706.0 Kc for MEDFER, illustrating the spectrum utilized by these experimental stations. The information was originally compiled by Mark Burkart and relayed to the rec.radio.shortwave newsgroup by Rick Robinson, KF4AR. The list serves as a snapshot of experimental beacon activity from the early 1990s, offering insight into the types of operations and the individuals involved in unlicensed, low-power transmissions. It highlights specific beacon IDs like "ABC SC" on 510.5 Kc and "GK HI" on 1620 Kc, alongside operator details such as Todd Roberts (WD4NGG) and Herb Vanderbeek (WY6G). While not a current operational guide, it is a valuable historical document for those interested in the evolution of LF/MF experimental radio and the early days of internet-based amateur radio information sharing.

Dchematics and photos of a secure power supply (short-cut, Rf feedback, high voltage etc.) by iz7ath

This page describes the loading coil (inductor) that W8WWV built for my center-loaded 160 meter band (1.83 MHz) vertical antenna.

High Power Solid State 600 Watts Output Motorola MRF 150 FETs

Based on VK5BR's Z-Match and designed for High RF Power covers 160 to 10 meters by VK6YSF

This high antenna require a large ground composed by 40 radials. It's not very handy expecially in windy situations but is very powerfull in pile-ups. In italian

Well documented Amateur Radio HF/VHF antenna projects, high power Russian GS35B RF amplifiers, mobile RFI solutions, related accessories, vintage radios, Six meter equipment, and useful techniques by K8CU are inside.

An easy to make HF low pass filter form high power

144 and 432 Mhz GS35b High Power Amplifier

We offer a large selection of standard and custom High Power RF and Microwave amplifiers for broadband, general communication, matched band, and personal communication markets.

SDR Receiver a compact high performance HF software defined radio receiver designed to be used in fixed or portable stations. Version 2 of the receiver is now available. It now has an RF pre-amplifier using a power MOSFET and other revisions to improve it's performance both as a stand alone receiver and as an IF panadaptor with HF and VHF transceivers.

The Discovery series of amplifiers are designed and built in the UK by Linear Amp UK Ltd, one of the world's leading amplifier manufacturers, specializing in high power RF tube amplifiers. The amplifiers use large GS31 or GS35 ceramic triode tubes. Band coverage 6m, 2m and 70 cms

High-power 3-500 HF linear amplifier by Don Pinnock G3HVA

The I0JXX is an italian company that offers market their projects, also sells electronic products of high quality, both for Ham, both Broadcast and their accessories. VHF Antennas, mosfet power amplifiers, filters, insulators, power dividers, telescopic poles, antenna masts

MARS, Israel's Antenna and RF System manufacturer, flat antennas for cellular, military broadband, multiband MF high power antenna

Manufacturers of high performance low power am transmitter products: sstran amt3000, bc-100, and the mw-250. for home and professional use.

D3+ High Performance Antennas for Field Day. This article describes versatile broadband wire antennas. These antennas will double your effective radiated power over a dipole, will be easy and inexpensive to build and install, and will be simple to match.

High Voltage Supply for GS 35B Amplifier

VU3NSH article on high current universal supply for rigs

Engineering Solutions for Unique Problems. Manufacturer of high Voltage, high Current, high Power Power Supply

Every ham needs an RF power meter. Here is a high performance unit to build at home.

High Power RF Amplifiers by Delta Sigma, Inc

An engineering oriented organization specializing in the design and manufacture of high performance parabolic antennas, 3dB high power RF couplers, Antenna power splitters, directional RF couplers and more items for RF transmission from HF through Microwave frequencies.

Construction details of a multiband dipole that can can operate at high power levels, and match its 50-ohm coax feedline without a tuner

SM5BSZ article on building VHF RF amplifiers

RF and Microwave Power Amplifier and Transmitter Technologies, amplifierlinearity, efficiency and available RF power devices.

RF Connectors Cable Assembly Attenuators Filters High Power VHF Amplifiers, Adapters MMCX MCX SMA SMB SMC BNC TNC N from RFAC Solutions

The _Italian VHF Beacons_ resource provides a detailed listing of active and QRT amateur radio beacons operating across VHF, UHF, and SHF bands within Italy. Each entry specifies the beacon's callsign (e.g., IQ1SP/B), operating frequency (e.g., 144.411 MHz), QTH locator (e.g., JN44VC), effective radiated power (ERP) in watts, and antenna configuration (e.g., Big Wheel, 4x Dipole, Yagi). This data is crucial for radio amateurs involved in propagation studies, equipment testing, and long-distance (DX) communication on these higher frequency bands, offering fixed signal sources for monitoring. This compilation, last updated in October 2005, serves as a historical snapshot of Italian beacon activity. For instance, it lists several 144 MHz beacons with ERPs ranging from **0.1W** to **10W**, and higher frequency beacons such as I8EMG/B on 1296.880 MHz and I3EME/B on 24192.132 MHz. The inclusion of QRT (Quiet Radio Teletype) status for many entries indicates the dynamic nature of beacon operations over time. Users can utilize this information to identify potential signal sources for band openings or to calibrate their receiving equipment against known transmissions.

Solartech Power Inc. manufactures, distributes and sells high efficiency solar panels and wind power turbines.

This program intended for electronic circuit analysis (mainly for Linux). ViPEC is a powerful tool for the analysis of high frequency, linear electrical networks.

A comeplete home made 600W LDMOS RF power amplifier. Settings can be made on a 7-inch touch screen, and on this screen you can see a lot of useful information during operation, such as output power, temperature, SWR, and so on. The power amplifier includes 2 MRF300 LDMOS FETs and several built-in sensors. The amplifier also contains several types of protection functions like too high current, too high swr, too high temperature, etc.

Demonstrates the operational status and reception reports for the SK6RUD/SA6RR QRPP beacons, which transmit on 478.9 kHz, 1995 kHz, 10.131 MHz, and 40.673 MHz. These beacons utilize extremely low power, with the 630-meter beacon operating at approximately 0.1 watt ERP into an L-antenna, showcasing the potential for long-distance contacts under favorable propagation conditions. The site details the specific frequencies and antenna types employed, such as a vertical at 500 kHz and a 1/4 vertical for higher bands. The resource compiles over 10,530 reception reports from amateur radio operators worldwide, logging details such as date, time, band, RST signal report, locator, distance, and receiver setup. Notable long-distance reports include a 500 kHz reception by AA1A-Dave from 5832 km in 2008 and a 10.133 MHz reception by ZL2FT-Jason from 17680 km in 2010, illustrating the global reach of these low-power transmissions. Each log entry provides specific equipment used by the reporting station, including transceivers like the Yaesu FT817, ICOM IC-7300, and various antenna configurations such as coaxial mag loops, inverted Ls, and end-fed wires. The primary objective of the SK6RUD beacons is to challenge conventional notions of power requirements for effective two-way communication, proving that contacts over significant distances are achievable with minimal output. The site also includes a submission form for new reception reports, fostering community engagement and continuous data collection on propagation phenomena across different bands. The detailed logs offer practical insights into real-world propagation characteristics and the efficacy of QRPP operations.

Magnetic Loop Antennas for The Radio Operator with Limited Space, a two part series of articles on how to construct a magnetic loop antenna, including directions on selecting high voltage tuning capacitor

Errante's virtual ground Balun, a state-of-the-art high power HF balun family.

The practice of converting computer server power supplies to make a very high quality high power supply at low cost is attractive. It doesn't normally require any modification to the supply but the hard part is figuring out how to trick them into turning on.

Communication Coil, Inc. designs and produces custom, high reliability Filter Networks, RF Coils, Chokes, Inductors, Baluns, Toroids and Power Magnetics for communications

1500 watts of RF output on the 70cm band requires robust amplifier design, a challenge addressed by this project featuring the GS-23b / 4CX1600U Svetlana tube. The resource details the construction of a high-power UHF amplifier, providing insights into component selection and layout necessary for stable operation at these frequencies and power levels.

This video will provide a foundation for understanding how power amplifier circuits work. If you are new to High Frequency Power Amplifier Circuit Design, this is the place to start.

Broadband over power lines (BPL) is a technique for transmission of high speed data (broadband Internet) over powerlines. Access BPL technology injects radio frequency energy into powerlines which were not designed for transmission of radio frequency energy, and leak substantial energy that causes interference to radiocommunications service

An High voltage power supply design by F1FRV

The MC3423 can protect sensitive circuity from power supply transients or regulator failure when used with an external "Crowbar" SCR.

HF/50 MHz 100W All Mode Transceiver. The FT-891 provides stable 100 W (25 W AM) high power output

Schematic diagram for a high voltage power supply by W4NFR

High Frequency Expermental Beacon "WV". The Beacon operates on the frequency of 13.55567mhz. This Beacon is very low power. It operates under Part 15 of the FCC Rules and Regulations. It transmits with only 1.5 milliwatts of power

Martek Power designs and manufactures a wide of high performance power supplies for various industries. Power supplies AC-DC, DC-AC inverters, DC-DC, EMI Filters

Demonstrates the construction of a high-power 6-meter (50 MHz) amplifier, specifically designed for demanding modes like EME, TEP, and multiskip Es. It details the use of a _GU-43B_ tetrode in a grounded-cathode configuration, emphasizing the need for stabilized grid voltage and input capacitance compensation. The resource provides a comprehensive schematic, power supply design, and practical considerations for component sourcing, particularly for high-voltage and high-current sections. The builder achieved an output power of **1250 watts** with an anode current of 0.65 amperes and 3200 volts anode voltage. The article also covers the physical construction within a modified P6-31 enclosure, outlining the internal layout for RF and power supply sections, and includes photos of the completed unit. It highlights critical safety precautions for working with high voltages and reactive currents up to **20 Amperes** in the P-network.