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A comprehensive resource center with DX aids, live propagation, callsign searches, news and bulletins, maps, and more by NW7US

AirNav live. See live images from my AirNav Radar box here in Clacton on Sea, Essex. Also full setup details.

The Collins TRC-75 autotune linear amplifier, owned by JF2SVU, is presented with a focus on its internal modifications. This QRO amplifier utilizes three 4CX250 tubes in parallel for its final stage, delivering 1 KW output power. Notably, the amplifier achieves full power with only 100 mW of RF input, a characteristic often associated with Collins designs. The original 400 Hz power supply has been converted for easier shack integration, and the entire RF and power supply sections have been rehoused into a compact, clean enclosure. The control unit, positioned above the amplifier, features three meters for individual vacuum tube IP monitoring and a multi-meter on the right. A dedicated 7 MHz receiver, recently completed, is also part of this integrated system. The autotune functionality means the main amplifier unit only requires connections for power, control, and coaxial cables, simplifying its operation. Key components like the 4CX250 tubes and NF capacitors are visible, along with the gearing mechanism for the final tank circuit. A timer and relay system manages high-voltage delay and cooling fan off-delay, although the cooling fan's airflow is noted as somewhat insufficient. A central volume control, which experienced a contact issue, is also highlighted.

LIVE 911 audio of the Chicago Fire Department North & South channels.

Operating a specialized DX cluster, this service provides real-time DX spots exclusively from stations confirmed to be _Log of The World_ (LoTW) users. This unique filtering mechanism allows DXers to prioritize contacts with stations that are highly likely to upload their logs to LoTW, streamlining the process of achieving confirmed DXCC or other awards. The cluster aggregates data from various sources, presenting a focused view of active LoTW participants across multiple bands. By narrowing the scope to LoTW-active stations, the platform significantly reduces the effort required for QSL management, as users can confidently pursue contacts knowing a digital confirmation is probable. This targeted approach is particularly beneficial for contesters and DXpedition chasers aiming for rapid award qualification, offering a strategic advantage in identifying viable contacts. The service supports both web-based access and traditional telnet connections, ensuring broad compatibility for amateur radio operators. It processes thousands of spots daily, with a focus on delivering accurate and timely information relevant to LoTW users, facilitating more efficient and productive operating sessions.

A live police broadcast for the Detroit area police department. Michigan Public Safety Communications System (mpscs)

Live audio feed from Denver Colorado Police

Echos of USAF (Formally NAVSPASUR) radar signals reflected off of meteor trails received at Roswell, New Mexico

PSK31 is a digital communications mode which is intended for live keyboard-to-keyboard conversations, similar to radioteletype. Its data rate is 31.25 bauds (about 50 word-per-minute), and its narrow bandwidth (approximately 60 Hz at -26 dB) reduces its susceptibility to noise.

Australia, Sydney Fire information and monitoring website, Live sydney radio fire stream.

Operating on the amateur radio bands, DXers rely on timely information to chase rare contacts. This resource offers a specialized web interface for accessing DX cluster data, specifically designed for mobile phone displays. It presents real-time **DX spots** in a compact, easy-to-read format, stripping away extraneous elements often found on traditional cluster interfaces. The core functionality focuses on delivering essential spotting information—callsign, frequency, mode, and comments—without requiring complex navigation or excessive data loading, which is crucial for mobile data usage. The utility of this mobile-first design becomes apparent when operating portable or away from a shack. Unlike full-featured _telnet clusters_ or web-based aggregators, DXLite prioritizes quick access and readability on small screens. The interface displays a continuous stream of spots, allowing operators to rapidly identify potential DX opportunities across various bands. Its minimalist approach ensures fast loading times and efficient data consumption, making it a practical tool for on-the-go DXing and contesting.

Germany's International Broadcasting Station with links to numerous pages in multiple languages containing program schedules, and live audio feeds.

The 23 cm amplifier pictured here delivers more than 300 watts with 10 watts drive.

Selecting appropriate cabling for amateur radio installations, whether for antenna feedlines, control lines, or station wiring, is critical for optimal performance and safety. This resource provides access to a manufacturer specializing in a broad range of electronic and electrical cables, including options suitable for various ham radio applications. Their product line encompasses standard and custom cable solutions, designed to meet specific operational requirements for both indoor shack setups and outdoor antenna systems. The company emphasizes _proven quality_ and compliance, with products certified by the Canadian Standards Association (CSA), Underwriters Laboratories (UL), and Intertek (ETL). Their quality management system is registered to _ISO 9001:2015_, ensuring consistent product standards. They offer competitive pricing and utilize AI-logistic tools for reliable on-time delivery, serving customers globally with technical support. Access to detailed technical specifications and an online quote tool is available for registered site members, facilitating precise cable selection for projects requiring specific impedance, shielding, or environmental ratings.

A 4 AMP / 18V regulated power supply schematic, designed by _ON6MU_, provides a detailed circuit diagram for constructing a robust power source. The design focuses on delivering a stable 18-volt output at up to 4 amperes, crucial for powering various amateur radio equipment. This resource presents a clear visual representation of component interconnections, including rectifiers, filter capacitors, and voltage regulation stages, essential for DIY enthusiasts building their shack infrastructure. The schematic's clarity facilitates understanding the power flow and component roles within the circuit. This circuit design offers a practical solution for hams needing a reliable 18V supply, potentially useful for driving specific transceivers, amplifiers, or accessory circuits. While specific performance measurements or comparisons to other designs are not detailed, the schematic itself serves as a foundational blueprint. Builders can adapt or modify the _power supply_ to suit their particular needs, such as integrating overcurrent protection or fine-tuning the output voltage with adjustable regulators. The straightforward presentation makes it accessible for those with basic electronics knowledge to assemble and troubleshoot.

Rutherford County Sheriff and Fire Live Scanner Audio Feed on RadioReference.com

Blackford and surrounding counties Police, Fire, EMS, and EMA.

Live streaming audio from Redding police, Redding fire, hospitals, ambulances, Fish and Game, Anderson police, search & rescue, CHP, and fire districts. Redding Californa.

DarkIce is a live audio streamer. It records audio from an audio interface (e.g. sound card), encodes it and sends it to a streaming server. Works on Linux and MacOSX

A live map of current KiWiSDR receivers available on the network. It allows users to explore a directory of web-controlled receivers for listening to HF and VHF stations worldwide. The site provides access to remote ham radio stations online, making it a valuable resource for amateur radio operators.

Live DX spots are presented through a _web cluster_ interface, utilizing both a world map and a Google Maps display for visualizing amateur radio propagation. The system provides real-time spotting data, enabling operators to track active stations globally. Users can observe current band conditions and station activity, which is crucial for optimizing contact strategies across various amateur bands. The platform's utility extends to contest operations and general DXing, offering a visual representation of where stations are being heard. While the primary function is DX spotting, the site also includes technical articles, such as instructions for interlocking two Flex Radios for single-transmitter compliance in contests, and a guide for constructing a simple **5KW** 1:1 balun for **160m/80m** dipoles using RG400 cable. This combination of live data and practical technical content supports both operational awareness and station improvement.

EchoLink and IRLP Internet Radio Linking Project Node's, Hurricane Watch Audio Feed's and Info, Live Scanner/Other Feed's from the USA, Local Ham Frequencies, Online Receiver's, Shoutcast Live Audio Feed's from the USA, Southern California Frequencies and more

Live Fire Radio Streams From Maryland, Delaware, PA.

Listen to the Baltimore City Police radio feed, carries all of the police districts in Baltimore City (BPD)

The grounded half loop describe in this article is basically a half wave length wire on 80 Meters. The 80M grounded half loop antenna, inspired by a 1984 QST article by SM0AQW, is a compact solution for limited spaces. Comprising a 127-foot wire fed against ground and supported by radials, it balances performance and practicality. Despite compromises in length and proximity to structures, the antenna delivers strong signal reports and effective multi-band tuning using an SGC 237 antenna coupler. Ideal for CW operation, it offers low SWR on 80-10M, though noise levels and safety considerations warrant attention. This versatile design excels in constrained environments.

This document details the design and construction of the PA70H, a 50-watt RF amplifier for the 70MHz (4-meter) amateur radio band. Built around the Mitsubishi RD70HVF1 MOSFET transistor, the amplifier delivers 45-55W output with 3-5W input power while operating on 13.8V DC at approximately 7-8A. The PCB design incorporates multiple protection circuits including overcurrent, SWR, and temperature control. The amplifier features various control modes including GND PTT, +13.8V PTT, and RF VOX. Two versions are available: PA70HLI (requiring 100mW input with additional driver) and PA70H (for 3-5W input). The comprehensive documentation includes circuit diagrams, assembly instructions, and performance data showing successful operation from both 100mW and 3.5W input sources.

This article compares two commercial vertical antennas for the 4-meter amateur radio band: the Watson WVB-70 half-wave and the Sirio CX4-71. The Watson measures 2.03m in length, costs around £40, and exhibited adequate performance but required additional waterproofing after rain affected its VSWR readings. The longer Sirio CX4-71 (3.02m) performed noticeably better, delivering signals approximately 2 S-points stronger than the Watson. The Sirio demonstrated high build quality, a stable 1.2-1.4:1 VSWR, and weather resilience, though minor VSWR fluctuations were observed during rain and frost. Both antennas are half-wave designs requiring no ground plane radials.

The resource, initially identified as "Alabama Radio," a dealer of amateur radios, antennas, CB equipment, scanners, and power supplies in Eastern Alabama, now redirects to a domain brokerage service. The original intent was to provide a commercial outlet for Ham Radio operators and CB enthusiasts seeking new equipment and accessories. This would have included transceivers, antenna systems, and various station components. However, the current content at the URL is _Startup Domains_, a platform for buying and selling premium .COM domain names. This shift means the resource no longer serves the amateur radio community directly. Instead, it focuses on digital asset transactions, with no mention of radio equipment, _DXing_, or _contesting_ activities. The original description of a regional radio dealer is no longer applicable to the live content.

CommCat Mobile is a free integrated spot management, remote radio control, and logging app for the iPhone. CommCat is required for remote control.

Live Fire/EMS feed from Eastern King County, WA as dispatched by Eastside Communications

FREE ham radio newsletter The K9YA Telegraph is in full-color and delivered to your computer each month as a PDF.

Community blog at livrjournal

Columbus Police Dispatch - Citywide Live Audio Feed

This site serves a community of volunteer and paid professionals in Search & Rescue and Civil Air Patrol who save lives and Amateur Radio enthusiasts who use DF skills as a hobby. We provide antennas and other resources for people in these fields.

Carteret County NC Public Safety Live Scanner Audio Feed

Listen to Missouri State Highway Patrol live scanner

Hose Company 1 East Rockaway Fire Department Official Page. Scanning FDNY & East Rockaway Fire

Rail Radio Communication Feeds broadcasted from all over the United States and beyond.

Long Beach Los Angeles county live scanner feed

Beginners guide and introduction to get started in ham radio if you live in India

Ten essential tips and truisms for understanding HF antenna: Non-resonant wire dipole antennas fed with open-wire line and an antenna tuner can function effectively as multiband antennas, as detailed in "The Classic Multiband Dipole Antenna" by WB8IMY in March 2004 QST. Coaxial cable, unlike balanced parallel-wire feed lines, can cause RF to travel on the outer shield braid, leading to RF feedback to the station; a 1:1 balun at the dipole center can mitigate this by isolating the unbalanced coaxial feed line. Antenna gain is achieved by shaping and directing RF energy, with beam antennas concentrating power in a specific direction, and wire antennas also exhibiting shaped radiation patterns. An antenna tuner's primary role is to match the transceiver's 50-ohm output to the antenna system's impedance, allowing modern transceivers to deliver full power. Wire antennas do not always require center feeding; end-fed long wires or off-center-fed dipoles (like the Windom) can be used, though they often necessitate an antenna tuner and a counterpoise or radial network. Dipole antennas do not need to be perfectly horizontal; their legs can be bent or inclined, which affects feed point impedance and may require SWR experimentation with coaxial feed. Vertical antennas shorter than a half wavelength require an efficient ground system, typically comprising elevated or buried radial wires, with more radials generally leading to better efficiency. A 1:1 SWR indicates an impedance match but does not guarantee antenna efficiency; an inefficient vertical antenna with a poor ground system can show a low SWR while wasting most RF as heat. Investing in high-quality, low-loss feed line, especially coaxial cable, is crucial for maximizing RF signal transfer and overall antenna system performance.

Manufacturer & distributor of vacuum tubes for all applications, we guarantee best service,pricing & delivery and we also guarantee sameday shipping.

This resource presents a domain name for sale, specifically _Kl7aa.com_, for $995, with an option for a 24-month payment plan at $41.46 per month. The page details the purchasing process, including immediate domain access, zero percent financing, and secure shopping. It also outlines the transfer process to other registrars like _GoDaddy_, clarifies what is included with the domain purchase (only the domain name, not hosting or web design), and explains how to maintain WhoIs privacy protection. The content includes testimonials from buyers like Dann Berg and Greg Shepard, highlighting smooth transactions and quick domain delivery. It also provides information on HugeDomains' 30-day money-back guarantee and frequently asked questions regarding domain transfers, access post-purchase, and payment plans. The page emphasizes the importance of a web address and lists other similar domains for sale, such as _Kl35.com_, alongside quick stats about the domain's length and structure.

This resource presents a domain name for sale, Grandicelli.com, which was previously associated with an HF-VHF-UHF-SHF digital monitoring site, Wavecom Decoder tools, Winradio and DRM decoders, a WD3000 Direction Finding System, Radioraft software, and a PFSL3000 Integrated HF-VHF-UHF signal monitoring system. The current page functions as a sales portal, providing information on the domain's price of $695, with an option for a 24-month payment plan at $28.96 per month with 0% interest. The page outlines the purchasing process, including quick delivery of the domain within one to two hours, and details the transfer procedure to registrars like GoDaddy. It also highlights customer testimonials regarding the ease and speed of domain acquisition through HugeDomains, emphasizing the 30-day money-back guarantee and secure shopping experience. The resource clarifies that only the domain name is included, with hosting and web design services needing to be sourced separately.

Live feed for NHP rural areas of Moapa Laughlin Primm Alamo Indian Springs

Tri-Cities Frequencies, Live Scanners, CTCSS information and more

City of Milwaukee Fire Department Live Audio Feed

Live audio of the National Hurricane Center’s Skywarn Nets. This live feed covers several different states, and locations throughout the US including: TX, LA, MS, AL, FL, GA, SC, NC, VA, MD, DE, PA, NJ, NY, CT, RI, MA, VT, and ME

Live Police and Fire scanner feeds from Albion PA, Erie County PA USA.

Two coupled PAs with each 2 times 2C39 deliver around 400W RF.