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Offer PC based virtual instrument for electronics enthusiasts, students and professionals, including full-fledged sound card real time Oscilloscope, Spectrum Analyzer and Signal Generator.

Over 200 Electronic Plans and Kits

KJI Electronics, Inc. has been serving the Amateur Radio Community since 1978. An authorized Icom and Kenwood dealer, we carry many other manufacturers of HAM radio equipment. Located in Caldwell NJ, we service the radios we sell.

For radio amateurs and electronics enthusiasts maintaining vintage tube gear, having accurate documentation for tube testers is crucial. Michael Marx, WB0SND, through SND Tube Sales, provides high-quality reproductions of these essential manuals. These aren't mere photocopies; each manual is digitally scanned, cleaned of imperfections, and professionally printed on a _Laserjet 5000_ with heavy card stock covers and plastic comb binding, often making them difficult to distinguish from originals. The catalog includes instruction manuals, schematics, and roll chart supplements for a wide array of classic tube testers. Operators can find documentation for popular models such as the _Hickok 539B/C_, _AVO CT-160_, and _B&K 700_, along with military-grade testers like the _TV-7_ and _USM-118_. Many listings also offer specialized supplements for obsolete or foreign tubes, ensuring comprehensive coverage for diverse tube collections. WB0SND's offerings extend to calibration instructions and data for specific adapters like the _Hickok CA-4_ and _CA-5_, providing critical support for precise tube testing.

Kenwood Ibérica's online presence details their extensive product line, including the NEXEDGE NXDN and DMR digital radio systems, alongside traditional analog offerings. The site categorizes transceivers by mode, such as HF / Todo Modo (All Mode), and portable/mobile VHF/UHF units, catering to various amateur radio operating preferences. This includes specific accessories like batteries, chargers, microphones, and programming cables, essential for maintaining and customizing radio equipment. The Spanish portal also highlights Kenwood's broader electronics portfolio, extending beyond amateur radio. This encompasses car electronics, featuring navigation and multimedia systems, as well as marine receivers and speakers. The product range covers everything from CD and CD-less car receivers to power amplifiers and DashCam/RearCam solutions, demonstrating the brand's diverse market reach. Beyond communications gear, the site presents home audio systems, including all-in-one receivers and portable party speakers. This breadth of offerings underscores Kenwood's long-standing presence in both the consumer electronics and two-way radio sectors, providing a centralized resource for product information and support.

GCARA is a general interest amateur radio club intended to promote amateur radio, electronics education and fellowship through amateur radio in the Greater Cincinnati Tristate - Indiana, Ohio and Kentucky area. The club service area lies within a circle having a radius of 25 miles from downtown Cincinnati.

The _Sci.Electronics FAQ: Repair: RFI/EMI Info_ document, authored by Daniel 9V1ZV, provides a detailed analysis of computer-generated RFI/EMI, focusing on its impact on radio reception. It identifies common RFI sources such as CPU clock rates (e.g., 4.77 MHz to 80 MHz), video card oscillators (e.g., 14.316 MHz), and even keyboard microprocessors, all of which generate square-wave harmonics across HF and L-VHF regions. The resource outlines a systematic procedure for pinpointing RFI origins, including disconnecting peripherals and using a portable AM/SW receiver with a ferrite rod antenna to localize strong interference sources. The document categorizes RFI mitigation into shielding, filtering, and design problems, offering practical solutions for each. It recommends applying conductive sprays like _EMI-LAC_ or _EMV-LACK_ to plastic casings of radios, monitors, and CPUs to create effective Faraday cages, emphasizing proper grounding and avoiding short circuits. For filtering, the guide suggests using line filters, ferrite beads, and toroids on power and data lines, and small value capacitors (e.g., 0.01 uF for serial/parallel, 100 pF for video) to shunt RFI to ground. It also discusses the use of bandpass, high-pass, low-pass, and notch filters on the receiver front-end or antenna feed to combat specific in-band noise.

Constructing a high-performance RF spectrum analyzer up to 1000 MHz requires careful attention to component selection, shielding, and circuit isolation. This resource details a project that improves upon the _Spectrum Analyzer for the Radio Amateur_ design by Wes Hayward (W7ZOI) and Terry White (K7TAU), incorporating ideas from Scotty Sprowls' project, particularly his 1013.3 MHz IF bandpass cavity filter. The analyzer utilizes a Mini-Circuits SRA-11 mixer with a sweeping local oscillator from 1013 to 2013 MHz, feeding into a 4-pole copper pipe cavity filter. The design employs a second SRA-11 mixer with a fixed 1024 MHz LO to produce a 10.7 MHz final IF. This signal then passes through narrowband resolution filters and is processed by Analog Devices AD603 and AD8307 ICs for IF amplification and logarithmic detection, driving an oscilloscope in X/Y mode. The project emphasizes modular construction, using salvaged components and double-sided FR4 material for PCBs, with critical notes on minimizing spurious images through effective shielding and proper voltage regulation for each module. Key components include a Z-Communications V585ME48 VCO for the first LO and a Z-Comm V583ME01 VCO controlled by a Motorola MC145151 PLL for the second LO. An optional Hittite HMC307 step attenuator and K&L 5L121-1000/T5000-O/O low-pass filter manage RF input. Tuning procedures for the 10.7 MHz IF resolution filter are also detailed, showing before-and-after spectrum views.

This resource is an online tutorial focused on setting up the Raspberry Pi for amateur radio applications. It covers the installation and configuration of various software packages tailored for digital communications and protocols, including _Packet Radio_ with Hamlib and Direwolf, as well as data modes like FLDigi and WSJT-X. The guide also details the integration of hardware components such as GPS clocks for time synchronization and real-time clocks for enhanced functionality. Users will find instructions for installing software like GPredict for satellite tracking and GQRX for software-defined radio (SDR) applications. The tutorial emphasizes practical steps, including the use of command-line inputs in the Raspberry Pi OS terminal, and provides troubleshooting tips for common issues such as faulty SD cards or insufficient power supplies. Operators are encouraged to explore various applications, including APRS iGates and WSPR beacons, to enhance their ham radio experience. The material is designed for licensed amateur radio operators with basic knowledge of electronics and computing.

Anatech Electronics manufactures RF filters for communication systems, Military and commercial, as well as RF filters for Wireless applications. Products include, Band pass filters, Duplexers, Low pass, high pass and bandstop filters. Additional products such as RF cable assembly also available.

Check out these vintage QSL cards from the 20th Century in this gallery of old QSL cards.

The TCARES membership provides communications assistance with fires, floods, search & rescue, and health & welfare message assistance to the Red Cross, without pay, using their own equipment, usually in twelve hour shifts.

The author fixed a friend's Kenwood TS-850S radio, which suffered from Capacitor Plague, a common problem in 1990s electronics where capacitors leak and damage circuit boards. The CAR board, responsible for generating signals, was especially affected. The author cleaned the board, replaced the capacitors, and repaired a broken trace. Although the radio mostly functioned afterward, the "Slope Tune" control behaved abnormally. The cause seems to be a software issue, not a hardware one.

Illustrates the potential for radio frequency (RF) energy from amateur transceivers to interfere with vehicle electronics, drawing parallels to military _Radio Frequency Vehicle Stopper_ (RFVS) technology. The resource details personal experiences with VHF/UHF signals activating household devices and then pivots to the complexities of RF interaction with automotive systems, noting the development of multi-frequency RFVS (MFRFVS) to overcome vehicle-specific vulnerabilities. It highlights that while car manufacturers conduct RF immunity tests, the rigor varies, with luxury brands likely performing more extensive evaluations than others who merely meet minimal certification. The article explores practical considerations for mobile amateur radio installations, suggesting antenna placement over the car, using lower power output, and proper grounding to mitigate adverse effects. It acknowledges the lack of comprehensive data on RF/vehicle combinations but emphasizes that adherence to these basic principles can reduce risks. The author shares observations of unexplained car computer codes in a 2002 SUV, speculating on potential RF induction. Concerns are raised about the increasing complexity and interconnectedness of modern car electronics, including Bluetooth, remote access, and electronic control systems for critical functions like steering and braking. The article points out the diminishing space for third-party installations in contemporary vehicles and references the ARRL's stance on auto manufacturer policies regarding amateur radio installations, which generally advise against them.