An automatically tuned 7-30MHz mobile antenna
- This is a base-loaded vertical antenna that mounts on the car's roof. The loading coil is designed as a variable inductor, with a three-legged chariot that travels up and down inside the coil, with grooved brass wheels running on the coil turns, and driven by a slotted rotor tube.
A Ham Radio Public utility HF Station
- Merging Internet technology with Amateur Radio holds great promise. This article discusses the authors’ experiences in putting several Internet Remote Base stations on the air.
By Stan Schretter, W4MQ, Brad Wyatt, K6WR, and Keith Lamonica, W7DXX
Radio Scanner Guideupdated
- A guide to selecting Radio Scanners; divides both new and used radio scanners into 6 categories, based on their specifications and features - e.g. analog trunking scanners, digital trunking scanners, etc; provides specifications on each model
- We specialize in pc-based data acquisition systems, test equipment, electronic components, disk on modules, choke and coils, diodes, capacitors and connectors, potentiometers, crystals, resistors, relays
- NEC4WIN is a 32 bits commercial antenna simulation software based on MININEC3 developed by the Naval Ocean Systems Center in the 70s and 80s. It runs under Windows and can be used to simulate, analyze and optimize wire antennas, beams, verticals, etc.
NEC4WIN has limitations. They are the same as Mininec3 on which the engine is based.
- FreqTweak is a tool for FFT-based realtime audio spectral manipulation and display for Linux. It provides several algorithms for processing audio data in the frequency domain and a highly interactive GUI to manipulate the associated filters for each. It also provides high-resolution spectral displays in the form of scrolling-raster spectrograms and energy vs frequency plots displaying both pre- and post-processed spectra.
Base-Station RF Power-Amplifier Biasing
- Power amplifiers used in base stations require biasing for proper RF performance. This article explains the two classes of biasing that are prevalent in the RF industry, analyzes their characteristics, and shows implementations with existing ICs.
DigChip IC database
- Provider of electronic components documentation. Offer a reliable tool to find semiconductors components technical information like parts, datasheets, cross reference, obsolete and new circuits.