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Operating in a Single Operator Two Radios (SO2R) setup, especially with beverage antennas, often exposes the receiving radio's front-end to significant RF energy from the transmitting radio. This resource details a practical, homebrew receiver protection circuit designed to mitigate this risk. The core of the design involves a non-inductive 2W 22 Ohm carbon composition resistor in series with the RX antenna line, followed by two stacks of four fast-switching diodes (e.g., _1N914_) configured in opposite polarizations. This arrangement effectively clamps the incoming voltage to approximately 2.8 V peak-to-peak, safeguarding sensitive receiver input components. The series resistor plays a crucial role by absorbing excess power, preventing the diodes from exceeding their current ratings and potentially failing open, which would leave the receiver unprotected. The author, _N4KG_, measured up to 50 watts of coupled power between 80M slopers on the same tower, highlighting the necessity of such protection. The design is presented as a cost-effective solution to prevent damage to receiver input transformers, with the author noting successful protection of a receiver even after a resistor showed signs of overheating. This simple circuit can be integrated via a transverter plug, offering a robust defense against high RF input.

Saskatchewan Hamfests Then and Now

Explores the re-establishment of SDRGadgets as an online shop, focusing on accessories for Software Defined Radio enthusiasts. The proprietor details the process of rebuilding the website and restocking products after a hiatus, emphasizing a commitment to affordability and user experience in the SDR hobby. The site aims to offer items that enhance SDR operation, such as VFO controllers, without significant financial outlay. Anticipates a refreshed product line featuring a "sleeker and more technical look and feel," leveraging new manufacturing technologies. The owner expresses enthusiasm for showcasing these redesigned items and expanding the inventory beyond initial offerings, inviting customer suggestions to tailor product development. Welcomes both returning customers and new visitors, acknowledging the current limited product availability during the rebuilding phase. The site promises worldwide postage and encourages interaction for product ideas, aiming to foster a community around practical, budget-friendly SDR solutions.

Voldatech, a manufacturer based in China, produces a range of RF feeder cables and site components essential for amateur radio installations and telecommunication infrastructure. Their product line includes various types of coaxial cables, such as **50 Ohm** and 75 Ohm options, along with a comprehensive selection of connectors like N-type, UHF, and BNC. These components are critical for maintaining signal integrity and minimizing loss in antenna systems, whether for a home shack or a remote DXpedition setup. The company's focus on _RF Coax cables_ and connectors directly supports the needs of radio amateurs seeking reliable transmission lines for their transceivers and antennas. Amateurs often compare Voldatech's offerings to established brands, evaluating factors such as impedance matching, shielding effectiveness, and durability under various environmental conditions. The availability of diverse cable types allows operators to select optimal solutions for different frequency bands and power levels, from QRP to high-power amplifier setups. Their products are particularly relevant for those constructing new antenna arrays or upgrading existing feedline systems, aiming to achieve maximum power transfer and reduce standing wave ratio (SWR) for efficient signal propagation.

DMR in Helena, Montana. Experiments in Digital Amateur Radio Communications

This page provides a detailed guide on the Guanella Current Balun for ham radio operators. The author shares very nice schematics, photos, and explanations on the construction and use of this type of balun. The content explains when a balun is needed and how it can help with common-mode currents in antenna systems. It also discusses the construction process, including winding the balun around a ferrite core. This resource is useful for hams looking to improve their antenna systems and reduce common-mode currents for better performance. This article is in Dutch.

The Clovis Amateur Radio Pioneers is a non-profit Amateur Radio Club located in Clovis, California

Ham Radio personal web site

DF0WD/DL4YHF's Longwave Overview details amateur radio operations on the 135.7 to 137.8 kHz segment in Germany. The author outlines the "inofficial" European band plan, specifying segments for QRSS, TX tests, beacons, conventional CW, and data modes. Early LF activities at DF0WD began with a 20-watt CW transmitter, later upgraded to a homemade linear transverter capable of 100 watts, driven by an Icom IC706 on 10.137 MHz. The station's antenna system includes a 200-meter wire, approximately 10 meters above ground, supported by football field light-masts. Despite its length, the antenna's efficiency is noted as very low due to the immense wavelength of about 2.2 km. The author's experience highlights the significant challenge of achieving effective radiated power (EIRP) on LF, estimating DF0WD's EIRP at around 80 milliwatts based on field strength measurements from PA0SE. DF0WD/DL4YHF has successfully worked numerous countries on 136 kHz CW, including DL, F, G, GI, GM, GU, GW, HB9, HB0, LX, OE, OH, OK, OM, ON, OZ, PA, and SM. The author also mentions ongoing efforts to log contacts with CT, EI, LA/LG, and to complete a two-way QSO with Italy, demonstrating persistent activity on this challenging band.

NARL homepage, the namibian amateur radio league

A club for all those who are interested in Amateur Radio, meet in the London Borough of Harrow which is located in North-West London, UK

Weblog from Florence Italy, with personal infos and updates on his ham radio activity

MARCA, Inc. operates approximately 24 repeaters across Arizona mountaintops and Phoenix-area rooftops, supporting modes like D-STAR and Fusion. The club, holding the **W7MOT** callsign, engages in diverse activities including ARRL Field Day events near Forest Lakes, AZ, ARRL FMT contests, and antenna experimentation. Members actively participate in HF operations such as voice, digital, CW, DXing, and various digital HF modes, alongside MESH and EOC operations within the valley. The club's interests span a broad technical spectrum, from SDR radio building to antique radio restoration, and include modern digital modes like WSPR, WSJT, FT8, and FT4. They also explore computer-based operations such as Echolink, fostering a dedicated Single Board Computer (SBC) and Raspberry Pi group. Monthly VE testing sessions for Technician, General, and Extra Class licenses are conducted by Ray Vasquez, K4RMV. Meetings are held on the third Tuesday of each month, typically lasting two hours, with a business segment followed by a technical presentation. These gatherings occur in-person at IHop in Mesa, AZ, and concurrently via Zoom, accommodating both local members and winter visitors. Informal chat groups often form post-meeting to discuss specialized topics like D-STAR, SDR, APRS, MESH, and Fusion.

St. Albans, VT

The WCARC is a general interest ARRL Affilated Special Service Club.

New Zealand Association of Radio Transmitters Auckland Branch 02

Associacao de Radioamadores de Amadora-Sintra Portugal

FPARC - Supporting amateur radio enthusiasts and SWLs in the Portsmouth area. Monthly meetings and summer Field Weekends using club call M0GZN and occasional Special Event Station GB1PF.

Tait Digital Mobile Radio (DMR) is an affordable digital communications platform that delivers a range of workforce efficiencies and operational benefits for mission critical users.

The Sandy Amateur Radio Club was organized on September 25, 2014. It is open to any and all licensed amateur radio operators and anyone who is interested in the hobby

The Pickens County Communications Group are volunteers for the Pickens County Emergency Management Agency in Pickens, S.C. and members of R.A.C.E.S.-Radio Amateur Civil Emergency Service, with the South Carolina State Guard. We are not a club. We are a group of amateurs radio enthusiasts with similar interests, dedicated in providing emergency communications for public service, public safety, and commercial communications for local agencies. We also provide Skywarn communications for Pickens County and the National Weather Service in Greer, S.C.

The Bella Vista Radio Club (BVRC) welcomes you to the NW Arkansas, SW Missouri and NE Oklahoma Area.

This site is established by a group of ham members who wish to see the interests of amateur radio in Malaysia protected.

Mason County Amateur Radio Club / Washington State USA

Radioamadorismo ,amador, ciência, comunicação, rádio, hooby, experiências from Brazil by PY3AB

The club is based in chingford, north east london

San Rafael, CA ham radio club

The Japan Amateur Radio web journal, CQ Web is a portal to radio related japanese resources established in 1995

Military Recreation Station and Club. Located on Elmendorf AFB and licensed since 1948. We provide a working Amateur Radio Station to Active Duty, Dependents and Retiree's. As well as DOD Civilians.

Our goal is to provide helpful and useful information to Ham Radio Beginners so you can get started as soon as you want to enjoy the amateur radio hobby.

927.1250 MHz Santiago Peak, CA USA

SMCC Amateur Radio Club - K9ONA

Ultimax antennas manufacturer of amateur radio End-Fed and bazooka antennas made in USA

Coastal Amateur Radio is for hams south of the Fraser. Even if you live north of the Fraser you are welcome to join in. Hams who come together for the love of HF & VHF in the hobby.

Crystal receivers are radio receivers that work without a power supply or batteries. Gallery of some crystal radio projects

Portuguese Amateur Radio Station with personal info and logs.

Liga Amadores Radio Sintra

The Primary N6OCS Repeater is located at 5700 feet on Santiago Peak in the Santa Ana mountains.

The RACES ARES Disaster Assistance Repeaters (RADAR) group was formed by a team of amateur radio operators dedicated to providing high quality repeater communications for amateurs involved in public service communications or response to emergency/disaster situations.

Pittsburgh, PA

What are the Differences between UV5R and UV82 Series

Frankston and Mornington Peninsula Amateur Radio Club

GM4YEQ Galashiels and District Amateur Radio Society (GDARS)

Broadcast listenening radio magazine in spanish

Using portable battery power is always a challange when operatin amateur radio in sota oprations. This article is about implementing lithium iron phosphate cells (LiFePO4) in ham radio portable operations.

Hytera, a leading designer and manufacturer of professional mobile radio communication equipment, offers complete and customized communication solutions to government, public security, utility, transportation, enterprise & business for higher organizational efficiency.

A mission of the club is to promote amateur radio by way of educational programming and activities. MCARC is an affiliated club with the ARRL.