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Three live police scanner streams are offered, broadcasting twenty-four hours a day from San Diego County. KE6CBF, the site's operator, provides real-time communications from agencies like the San Diego Police Department (SDPD), San Diego Fire-Rescue Department (SDFD), Sheriff, California Highway Patrol (CHP), and Air Traffic Control (ATC). Beyond the live audio, the platform includes a community forum for scanner enthusiasts. It also provides resources such as FAQs, _10-43_ information pages, and police codes to assist listeners in understanding the transmissions. The site aims for high-quality streaming audio with minimal downtime, supported by user donations. Powered by technologies like PERL, mySQL, ICECAST, APACHE, and LINUX, the site is designed for optimal viewing at **1024 x 768** resolution or higher.

Demonstrates the construction of a **multi-band HF mobile antenna** utilizing a modified CB whip antenna base. The resource details the process of stripping a commercial CB whip, winding a new helical coil with 0.7mm insulated copper wire, and identifying tapping points for various HF bands. It emphasizes the importance of a rugged, slim design for mobile operation, discussing mechanical length, power handling (up to 200 watts), and coil diameter considerations. The article includes a graphic illustrating the antenna's operational principle, where sections of the helical coil are shorted from bottom to top to maintain efficiency and high Q. The resource presents a practical approach to achieving **band switching** without an external tuner, by manually adjusting tapping points on the coil. It provides a table with reference lengths in centimeters from the feedpoint for 7 MHz (40m) through 28.7 MHz (10m), including WARC bands. The author details mounting techniques, suggesting a Diamond bracket for secure attachment to a vehicle trunk, and stresses the critical role of proper grounding for optimal performance. The design allows for operation on 75m and 80m bands by adding a 110mm steel whip.

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!

Schematics plans by K9GDT and all infos to build a 600 Watt HF Amplifier. The amplifier uses four Motorola MRF150 50 volt TMOS power FETs configured in push-pull/parallel and biased for class AB linear operation.

Sixty-four years of operating experience inform Glynn E. "Buck" Rogers Sr., K4ABT's, insights into the J-Pole antenna, which he describes as a direct descendant of the _Windom_ or _ZEPP_. His first article on the J-Pole appeared in HRC magazine in 1958, and he has since published numerous pieces in publications like CQ Magazine, consistently referring to the J-Pole as a Windom with a folded-back short section forming the parasitic element. He emphasizes that both the Windom and J-Pole are powerful multi-band antennas, performing exceptionally well at harmonics of their fundamental design frequency, and advocates for 50-ohm coaxial cable with a _BALUN_ at the feed-point to avoid RF energy losses. K4ABT details the J-Pole's features, noting its ease of erection, lack of radials, low angle radiation, greater bandwidth, and immunity to terrestrial noise. He highlights its suitability for local nets and distant repeaters, claiming more gain and durability than most ground planes, and its ability to meet stealth antenna requirements. The guide provides specific dimensions for 2-meter (145.000 to 146.000 MHz) and 6-meter (50.500 to 51.500 MHz) J-Pole antennas, including measurements for the long driven element, short tuning stub, and spacing. The construction section illustrates a modified feed technique using an SO-239 chassis-mount coax connector soldered into a copper tee, deviating from the usual hose clamp method. The author also discusses the use of _EMT_ (electrical metallic thin-wall conduit) as an alternative to copper in earlier days. He cautions against building a 75-meter J-Pole due to its impractical length, reinforcing the antenna's optimal application for VHF and UHF bands.

This resource details the fundamental aspects of deploying longwire antennas, emphasizing ease of construction and installation for shortwave listening (SWL) and broadcast reception. It covers wire gauge selection, suggesting 14 to 24 AWG for general use, with heavier gauges (14-20 AWG) for permanent outdoor installations. Guidance is provided for various deployment scenarios, including indoor setups where the wire can be run around a room, temporary outdoor installations from balconies using light 18-24 AWG wire, and permanent outdoor configurations requiring higher placement and slack for tree movement. Feeding methods are discussed, recommending coaxial cable (50-75 ohms) to mitigate man-made interference, with instructions for connecting only the center conductor to the longwire. Safety precautions are highlighted, particularly avoiding contact with power lines and conductive materials, and managing static electricity buildup by unplugging the antenna after use and bleeding off charges before connection. The article also advises against using outdoor longwires during thunderstorms or snowstorms due to static and lightning risks. Optimal height considerations are presented, advocating for the highest safe placement, ideally a couple of feet above underlying structures, to maintain free air space. The text mentions a personal setup with one end at a roof peak (20 feet) and the other at a 17-foot mast, illustrating practical deployment without strict height requirements beyond safety and clearance.

Demonstrates the construction of **magnetic loop antennas**, detailing both multi-turn and single-turn designs. It covers a 30-inch diameter multi-turn loop for 80 meters, based on a February 1996 QST article, and an octagon single-turn loop made from 15mm copper tube with a 4.8-meter circumference, operating from 7 MHz to 14 MHz. The document also presents a smaller 800mm diameter loop for 14 MHz to 28 MHz, emphasizing the importance of high-voltage tuning capacitors. Covers the design and construction of custom **butterfly capacitors** and piston capacitors, including a split stator capacitor with 140 pF capacitance and a 6000 Volt rating, and a butterfly capacitor with 5-65 pF and 7200 Volt rating. It explains why butterfly capacitors are preferred over split stator types for high power applications due to lower losses and direct series connection of rotors, reducing resistive losses from wiper contacts. Material recommendations include clear PVC for plates and brass or stainless steel for non-magnetic hardware. Addresses practical considerations such as feeding the loop with a shielded 1/5 Faraday loop made from RG213 or RG8 coax, achieving VSWR 1.1 across bands, and optimizing its placement 180° from the capacitor. It also discusses mechanical joint resistance, dissimilar metal oxidation prevention using Vaseline, and a simple method for determining radiation angle with a TL-light tube. The guide includes diagrams for rotor, stator, and end plate construction.

Presents the official online presence for Yaesu, a prominent manufacturer of radio communication equipment. The site details their extensive product lines, encompassing amateur radio transceivers, antenna rotators, tuners, amplifiers, and various accessories like microphones, speakers, and power supplies. It functions as a central hub for product information, specifications, and support resources. The resource categorizes its offerings across several key areas, including **Digital Mobile Radio (DMR)** solutions, HF/VHF/UHF transceivers, and specialized receivers and scanners. Each product section typically includes model numbers, feature highlights, and often links to manuals or technical documentation, providing hams with essential data for equipment selection and operation. Beyond amateur radio, the site also covers Yaesu's contributions to aviation and marine radio sectors, illustrating the company's broader scope in wireless communication technology. It serves as a direct portal for accessing manufacturer-provided details, ensuring accuracy and currency for those researching Yaesu gear.

Presents _Henry Radio Inc._ as a manufacturer of solid-state RF power amplifiers, detailing their capabilities across HF, VHF, and UHF bands. The company designs and builds custom amplifiers tailored for various applications, including amateur radio, commercial broadcasting, military, scientific, and industrial uses. These amplifiers are manufactured in the USA, emphasizing domestic production. Beyond amplifier manufacturing, the resource highlights Henry Radio's role as a distributor for _Bird RF Test Equipment_, including wattmeters, dummy loads, and attenuators. It also mentions _Tohtsu Coaxial Relays_ and a range of miscellaneous amplifier parts and electronic accessories, providing a broader scope of communication equipment offerings. Additionally, the site describes a trunking two-way radio system operating on the 450-476 MHz band, covering significant portions of Los Angeles and Orange County. This service caters to professional dispatch needs for ambulances, taxis, and other commercial entities, requiring no long-term contracts.

MFJ manufacturer of ham radio antenna products, antenna tuners, antenna analyzers, morse code & CW, SWR wattmeters, antenna accessories , power supplies, audio filters, TVI filters, baluns, coax switches and more

RM is an Italian company operating in the radio communication field since 1974, main products are: HF-CB-VHF-UHF-Dual Band RF Power Amplifiers, Power Supply, DC-DC Converters Antennas and more products.

Presents the WA7BNM Contest Calendar, a long-standing resource for amateur radio operators seeking contest schedules and rules. Bruce Horn, WA7BNM, compiles comprehensive listings that include an _8-Day Calendar_ for immediate planning, a _5-Week Calendar_ for near-term strategy, and a _12-Month Calendar_ for broader outlooks. The site also offers specialized views like the Perpetual Calendar for predictable events and a dedicated section for State QSO Parties. Operators can access historical data back to **2005** and customize their calendar views to filter for specific modes or QRP power levels. The calendar integrates with modern tools, providing RSS feeds, iCal downloads for desktop calendars, and direct links to Google Calendar for seamless integration. This resource is a staple for contesters, offering essential details like log due dates and links to official contest sponsor rules.

Base station and repeater antennas, mobile antennas, ,multi-band HF antennas , handheld transceivers, receiving and scanner antennas, power meters, swr meters, power supplies, coaxial switches

Antenna Restrictions, Power Restrictions, RFI Problems, or Limited Space keeping you off the air?

Amateur radio operators often seek reliable equipment for various modes and bands, from QRP operations to high-power DXing. Historically, Ten-Tec has been a notable manufacturer in the amateur radio market, known for its range of products including HF and VHF transceivers, RF amplifiers, and antenna analyzers. Their product line also encompassed specialized items such as QRP transceivers and kits, catering to enthusiasts of low-power communication, and antenna tuners for impedance matching. The company's offerings included test equipment vital for shack setup and maintenance, like SWR meters and RF analyzers, which assist in optimizing antenna systems and ensuring efficient power transfer. Additionally, Ten-Tec provided various accessories and components, supporting both commercial products and homebrew projects. The brand was recognized for its _made in the USA_ manufacturing, appealing to operators who prioritize domestic production. While the website currently displays limited product information, it mentions upcoming items like the _MODEL 594 PHOENIX_ and the _Tune-A-Tenna_, indicating potential future product releases.

The website https://www.qsl.net/dl5dbm showcases homebrew projects related to KW, 2-meter, 6-meter, antennas, amplifiers, preamps, power supplies, and more. It provides information and resources for radio amateurs interested in DIY projects and experimentation.

ACOM international, manufacturer of HF power amplifiers, HF Antennas, Antenna tuners, Switches and Crankup masts

Zetagi CB amplifiers, 10m amplifiers and accessories, power supplies, microphones, SWR and power meters, battery charges manufacturers based in Italy. - Company out of business since 2024.

Monitoring shortwave broadcast stations effectively requires accurate schedule information to identify transmissions. This online utility offers a straightforward, graphical interface designed to search for and display current shortwave radio broadcasting schedules. Users can precisely filter results by frequency, specific language, broadcaster, time of day, and even by shortwave band, which simplifies the process of pinpointing desired content. The database, last updated on March 26, 2023, details station callsigns (e.g., BBC), start and end times in UTC, days of the week, broadcast language, transmitter power in kilowatts, and azimuth. Crucially, it includes the precise geographical coordinates of transmitter sites, such as Woofferton in the UK or Al Seela in Oman. This data is invaluable for predicting signal paths and optimizing antenna direction for improved reception, a key consideration for serious SWLs. For instance, a search for BBC English broadcasts at 21:04 GMT quickly reveals multiple active frequencies like 17780 kHz from Woofferton, offering a clear overview of current transmissions. The tool processes queries rapidly, returning results within seconds, demonstrating its efficiency for broadcast listening enthusiasts seeking timely information.

Use 4CX10000D / 8171, RF output power of 11 KW in key-down carrier on all bands. Power was measured with a Bird 4712 wattmeter and a 25 KW slug

Optimizing the impedance transformation and common-mode current suppression in antenna systems often involves selecting an appropriate balun. This project presents a **hybrid balun** design, combining characteristics of both voltage and current baluns to achieve superior performance, particularly when used with an antenna tuner. The design addresses issues like **common-mode current** on the feedline, which can distort the antenna's radiation pattern and introduce RFI in the shack. The construction details include winding techniques for the toroid core, component selection, and practical considerations for integration into an existing antenna system. Performance comparisons are drawn against conventional balun types, highlighting the hybrid balun's effectiveness across the HF bands. The resource provides insights into the current distribution and impedance matching properties, crucial for efficient power transfer and reduced SWR.

Determining the actual need for an antenna tuner often hinges on the specific antenna and feed line configuration in use. While many hams believe a tuner is always essential, its primary role is to present a 50-ohm impedance to the transceiver, not to "tune" the antenna itself. For instance, a resonant dipole fed with _coaxial cable_ at its design frequency typically requires no tuner, as the feed line impedance closely matches the radio's output. However, operating a non-resonant antenna, or using a resonant antenna on multiple bands, frequently necessitates a tuner to manage high Standing Wave Ratio (SWR) on the feed line. The article clarifies that a tuner placed at the transceiver only matches the radio to the feed line, not the antenna to the feed line. For maximum efficiency with a non-resonant antenna, an _automatic antenna tuner_ (ATU) or a remote tuner placed at the antenna feed point is often more effective, minimizing losses in the feed line. The discussion also touches on the practical implications of SWR, noting that modern transceivers often fold back power at high SWR, making a tuner a practical necessity to achieve full output power, even if the antenna itself is not perfectly matched.

The project details a DIY SWR/Wattmeter designed around an _Arduino Uno_ shield, providing capabilities to measure RF power from 2 to **200 watts** and Standing Wave Ratio (SWR) for HF amateur radio bands. This construction features a compact design, integrating the measurement circuitry directly onto a custom PCB that interfaces with the Arduino Uno microcontroller. Key components include a directional coupler for sensing forward and reflected power, precision rectifiers, and analog-to-digital conversion for processing RF signals. The Arduino firmware handles calibration, calculations, and displays the results on an integrated LCD, offering real-time feedback on antenna system performance. The design prioritizes simplicity for homebrewers. Performance specifications indicate accurate readings within the **2-200W** power range, suitable for typical QRP to medium-power HF operations. The project provides schematics and a basic overview of the software logic.

NGC is now distributor for COMET and MALDOL brand antenna products designed, manufactured in Japan. Distributor of DAIWA brand RF SWR/power meters and switching power supplies, antennas, test equipment, antenna analyzers and more

Oscilloscope, Realtime spectrum analyzer, Impedance meter, RLC bridge and signal generator for Windows. Is a Windows application that converts your PC into a powerful dual-trace signal analyzer (oscilloscope, FFT etc...) . Uses your PC sound card as an Analog-to-Digital a Converter to digitize any input waveform and as Digital-to-analog Converter for the signal generator. True 24 bit adc/dac 48K/96k/192k sampes/sec.

A 20 ampere and more 13,8V power supply for RTX

Amateur radio HF amplifiers and power supplies manufactured in Australia

Project for a 12 volt, 30 ampere Power Supply Unit

500W Power Amplifier by Harry Lythall - SM0VPO

Galaxy DX 47HP and DX 99V2 models are highlighted, showcasing the manufacturer's current offerings in both amateur and Citizens Band radio transceivers. The site details several amateur models, including the DX 29HP, DX 44HP, DX 55HP, DX 98VHP, DX 33HP2, and DX 94HP, catering to different operational needs and power levels. For CB operators, a range of models like the DX 2547, DX 979, and DX 929 are presented, with specific features such as _StarLite_ front panel lighting for low-light conditions, as seen on the DX 929 and DX 979. The DX 979 is noted for its compact form factor and SSB capability, making it suitable for installations where space is a constraint. Conversely, larger models like the DX 939, DX 949, and DX 959 are available for those with more room, offering features such as blue lighting and integrated frequency counters. The DX 939, for instance, combines aesthetic appeal with functional design, providing clear readouts and robust audio performance. A downloadable CB radio shopping guide is also offered, enabling users to compare Galaxy's product specifications against other radios on the market, facilitating informed purchasing decisions.

SigJenny turns your PC into a flexible and powerful audio signal generator for free. It can create multiple waveforms, sweep, fire single or repeating tone bursts. You can save your sound as a wav file, display a frequency response, use SigJenny a bit like an oscilloscope, and do a very good impression of a police car!

11 Meter CB, 10 Meter Amateur Ham, FRS, GMRS Radios, Test Meters, Scanners, Antennas, Microphones, Power Supplies, Inverters, Accessories and Technical Reference Information.

Amateur Contact Log (AC Log) by N3FJP is a commercial Windows-based general logging program designed for amateur radio operators, supporting Windows 7 through 11. It provides comprehensive tracking for various operating awards, including Worked All States (WAS), Worked All Counties, Worked All Countries (WAC), DXCC, VUCC, Grids, Zones, IOTAs, and Lighthouses. The software features a customizable user interface, allowing operators to display specific data fields and adjust font sizes. It includes built-in databases for counties and countries, facilitates queries by band, mode, or power level, and offers a bearing and distance calculator for DX contacts. AC Log also provides DX spotting via Telnet or packet TNC, supports keyboard CW, and can play wave files. The program offers full support for ADIF import and export, enabling seamless integration with external services like eQSL, QRZ, Club Log, and the ARRL's Logbook of the World (LoTW) for QSO uploads and confirmation downloads. It interfaces with popular transceivers from Elecraft, Icom, Kenwood, Ten Tec, and Yaesu, and connects with digital mode software such as WSJT-X, Fldigi, and JTAlert via API. AC Log includes a Net Manager form for group logging, prints basic QSL label strips, and integrates with QRZ and Ham Call lookup services. The software is fully networkable for multi-PC operation, supports Parks on the Air (POTA) logging, and displays worked entities and DX spots on a real-time world map. Full featured Trial version available for 45 days

Demonstrates the construction of a **remote antenna tuner** utilizing a standard radio-controlled (RC) servo mechanism to adjust a variable capacitor. The design focuses on enabling remote tuning for narrow-bandwidth antennas, specifically mentioning frame and packing crate antennas, from within the shack. It covers the mechanical arrangement for integrating the servo with a capacitor and provides a circuit diagram for a control unit that generates the necessary 0.5mS to 1.5mS pulse-width modulation (PWM) signals to drive the servo's 180-degree rotation. This setup was successfully tested with up to 20 watts RF power without arcing or adverse effects on the servo, though tuning was performed at 1 watt for VSWR readings. The resource highlights the use of inexpensive, readily available components, such as Futaba servos, and details critical considerations like power supply decoupling with a 47uF capacitor to prevent unintended servo movement upon power-off. The system provides a practical solution for optimizing antenna performance for specific frequencies without manual adjustment at the antenna itself.

3 elements VHF Yagi homebrew antenna designed with YAGIMAX 3. Maximum forward GAIN is about 8,17 DBi. This antenna offering an effective radiation power 4 times greater of the transceiver output by SV1BSX

Constructing a **reduced-size coaxial Moxon rectangle** antenna for the 17-meter band is detailed, presenting a method to achieve a compact directional antenna. The resource outlines the use of RG-58/U coaxial cable for elements, enabling a substantial reduction in physical dimensions compared to traditional wire or tubing Moxon designs. It provides specific instructions for tuning coaxial elements using an **MFJ-259B antenna analyzer**, including a formula to calculate trimming lengths based on measured resonance and desired frequency. The article explains how to prepare the coaxial cable for both driven and reflector elements, specifying connections for testing and final assembly. Performance data from an MFJ-259B shows SWR readings between 1.0 and 1.2 across 18.068 MHz to 18.168 MHz, with R values from 51 to 59 ohms and X values of 0 or 6 ohms. The antenna's power handling is approximately 500 watts continuous, limited by the RG-58/U coax. Comparative receive testing against an All-Band Sterba Curtain at 50 feet indicated a 2 S-unit reduction for the coaxial Moxon at 9 feet, suggesting optimal performance at a height of 34-40 feet for a 15-18 degree take-off angle. The design achieves an electrical quarter wavelength with over 30 percent size reduction.

13.8 V 15A from a PC power supply

Alinco's factory in Toyama, Japan, holds ISO9002/140001 certification, underscoring its commitment to quality manufacturing processes for amateur radio equipment. The company produces a diverse range of products, including HF transceivers, mobile VHF/UHF radios, handhelds, and scanners, serving both new and experienced operators within the ham radio community. Their product line extends beyond transceivers to encompass essential accessories such as antenna tuners and power supplies, which are crucial for complete station setups. These offerings support various operating environments, from portable field operations to fixed home stations, ensuring versatility for radio amateurs. Alinco, Inc. Electronics Division is headquartered at Yodoyabashi Dai-Bldg 13F, 4-4-9 Koraibashi, Chuo-ku, Osaka 541-0043 Japan, maintaining a global presence in the amateur radio market.

Members discuss the operation of and modifications to this outstanding QRP rig that covers 160m 70cm with all modes. Site contains a large database of FT-817 FAQs and data files. Antennas, tuners, and power sources are also covered as related to this ultra-compact transceiver.

Maco Manufacturing, HF Antennas, gamma matches, cable assemblies, power supply, swr meters, watt meters

Get maximum power to your antenna by learning how to hook up and use a tunner to properly "trick" your rig

Difona is a german base dealer for amateur radio transceivers, anntennas, PA, power supplies, accessories from several brands like Kenwood, ICOM, Yaesu, MFJ, ACOM, DAIWA, Diamond, DXSR, Alinco, Ameritron, ETM, Fritzel, UKW Technik, AOR, Bencher, Create, G.B., Heil, Hotline, Maldol, Tonna, Titanex, Outbacker, Hy-Gain, Mirage, SCS, SGC, SSB Elektronik

Building a directional antenna for limited space, M0MRR shares his experience constructing a 10-meter Moxon rectangle. Initially using fiberglass fishing poles and a plastic breadboard, he achieved a 1:1.2 SWR across the band with 50 watts, making contacts as far as PY2TO from the UK. The design incorporates 10-amp power cable for elements and RG58 coax with crocodile clips for feeding, demonstrating a cost-effective approach. His field observations confirm the directional properties, noting European signals fading when facing Stateside, and receiving better reports from stations in the antenna's favored direction. While not formally measured, the front-to-back ratio appears effective. The initial build was somewhat flimsy, intended for temporary deployment, but proved effective for DX. Later, M0MRR constructed a more robust 10-meter Moxon using tubular aluminum pipe, indicating an evolution in his design approach for durability. The project highlights practical antenna building for small backyards, emphasizing the benefits of a directional antenna even with modest power.

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).

Complete real time signal analysis software with wide range of powerful FFT spectral analysis tools, statistics functions and comprehensive visualization system.

Ham radio dealer based in germany offer RF power amplifiers, from Alpin and SPE, antennas, RFI suppression products and GSM GPRS products

This sketch will read RF power and SWR from any SWR bridge, designed to work on VHF UHF bands

W7TDC modification of the Ameritron AL-80A power amplifier

HF amplifiers manufacturer maker of HF-2000 RF power amplifier

Midland Consumer Radio, Inc. is one of the most experienced and respected names in radio equipment. Midland offers the broadest line of CB transceivers in the industry, Amateur radio transceivers, VHF marine transceivers, VHF power amplifiers, and RF equipment for the broadcast industry.