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HF Ham Radio antennas for apartments and methods of shortening antennas -
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The latest and best yagi beams for 432MHz tested and optimized with NEC -
Catalogs a diverse array of Software Defined Radio (SDR) projects and realizations, systematically classified by their sampling methodologies and underlying hardware architectures. The resource delineates projects into categories such as those utilizing soundcard sampling of traditional transceiver audio outputs (Type Ia), mono soundcard sampling of intermediate frequencies (Type R1x-x-xx), stereo soundcard sampling of I/Q IFs (Type Q1x-x-xx), dedicated stereo audio ADC sampling of I/Q IFs (Type Q2x-x-xx), direct antenna RF signal sampling with off-the-shelf acquisition boards (Type R3x-x-xx), dedicated RF ADC sampling of analog IFs (Type R2x-x-xx), dedicated RF ADC sampling of direct antenna RF signals with ASIC-based processing (Type R4x-A-xx), FPGA-based processing (Type R4x-F-xx), and specialized IF chipsets combining ADC and DDC functions (Type Dxx-S-xx). Each entry provides a brief description, often including pricing, availability of source code, and specific hardware components like ADCs, DACs, DDS, and FPGAs. The compilation presents various practical applications, from PSK31 and Packet radio implementations to adaptations of the DRM standard for amateur radio bandwidths, such as Hamdream and WinDRM. It features specific hardware designs like the SoftRock-40 for the 40-meter band, the Firefly SDR for 30m and 40m, and more complex systems like the Quicksilver QS1R, which employs a 16-bit 130 Msamples/s ADC and an Altera Cyclone III FPGA. The resource also lists sample processing software, RF front-end designs, and academic/commercial SDR initiatives, offering insights into different approaches for I/Q conversion and digital signal processing in SDR systems. -
This multiband wire antenna it is an off centre fed dipole, with 10 feet of vertical radiator, needs no tuner on 40m, 20m and 10m and works fine on all bands above 40m with a tuner, and even below 40m on 60m, and 80m. -
Also known as the Backpacker's Delight Antenna. This Folding J Pole Antenna is the original design of Mike Heiler KA0ZLG and was featured on the Front Cover of the March 2005 QST Magazine. -
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2m SSB/CW-12.5 Ohm Yagis with extrem high gain and small bandwidth. These Yagis were constructed as ultra-light, portable Yagis with extrem high gain. They have small bandwidth and are working from 144,0-144,8MHz with good SWR. -
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An F150 and Yaesu FT-857, ATAS-120 No-drill Install -
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Amateur Radio, Citizen's Band Radio, Commercial Radio, General Electronic items, Marine Radio, and Short Wave Radios. -
Multiband Center-Loaded Off-Center-Fed Dipole (CL-OCFD) antenna that work on 80m 40m 30m 20m 15m 10m. The Center-Loaded Off-Center-Fed Dipole (CL-OCFD) antenna, developed by Serge Stroobandt, offers a versatile solution for amateur radio enthusiasts, covering multiple HF bands (80, 40, 30, 20, 15, and 10 meters) without the need for an antenna tuner. This innovative design utilizes a capacitor for resonance on the 80-meter band and a resistor to manage static charges. The CL-OCFD enhances bandwidth and simplifies operation, making it a significant advancement on OCF Dipole design. -
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The Double Bazooka Dipole is a very efficient single band antenna which is very quite, and does not require the use of a balun. This antenna consists of coax (RG58) or other 50 ohm type with the shield split at the center and the feedline attached to the open ends -
Demonstrates the construction and performance of an updated ZS6BKW multiband dipole, a variant of the _G5RV_ antenna, specifically designed for HF operation. The article details a real-world installation using 13.5m copper wire elements and 12.2m of 450 Ohm ladder line, configured as a sloping inverted-V with the apex at 10m and ends at 4m above ground. It covers the critical aspect of impedance matching, incorporating an 8-turn choke balun at the feedline transition to RG-58U coax to mitigate RF common mode current. Measurements confirm favorable SWR readings below **1.3:1** on 7.1 MHz, 14.11 MHz, 18.06 MHz, and 24.8 MHz, indicating effective resonance across 40m, 20m, 17m, and 12m bands. The installation also shows usable SWR dips on 3.55 MHz (5:1), 29.02 MHz (2:1), and 50.84 MHz (3:1), extending its utility to 80m, 10m, and 6m with an antenna tuning unit. Initial on-air results report clear reception of stations over **5000km** away, validating its DX potential. -
CB radio's catalog with photos and features, in czech. -
Australian dealer, HF linear amplifiers, power supplies, baluns, HF UHF yagis and verticals including multiband HF verticals. -
The KJ5VW 20 Meter Mini Yagi by Gary R. Hanson, Austin, Texas -
An easy to make trap dipole antenna for 40 and 20 meters -
DTMF decoder program that uses the sound card and FFT to decode DTMF by KB5RYO -
4CX250B X2 K2RIW style 2m amplifier -
Two mods for the Yaesu FT-950 -
A delta loop wire antenna plan for the 7 MHz band (40 meters) that is quick to setup and work with -
Low (or zero) Cost Accessories for the FT-817 Portable QRP MF/HF/VHF/UHF Transceiver -
A mobile setup using a dipole antenna for 10 to 80 meters band in italian -
Four band lightweight antenna, that rolls up into an small Grundig antenna case by N0LX -
The Windom is an Off-center wire multiband Antenna. The old version was fed just by a single-wire connected on 1/3 of antenna's overall length or with an open-line feeder (later versions). Here is another model with coaxial feeder, which is compatible with Solid States - 50 Ohm output transceivers . -
KD6WD introduce moxon rectangles, and in particular explains how he built a moxon antenna for 15 17 and 20 meters band with excellent pictures -
EI7BA Multiband Cubical Quads projects, includes two elements quad antennas for 10 12 15 17 20 meters band. Performance considerations, detailed pictures and construction notes. -
A very easy to use program to decode DTMF dial tones found on telephone lines with touch tone phones. The DTMF Decoder is also used for receiving data transmissions over the air in amateur radio frequency bands. -
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Large picture and technical specifications by rigpix -
Online calculator for Logarithmic Periodic Dipole Antenna LPDA -
An antenna for the 2-meter band, made by sliding coax insulator braid over a glass fiber bicycle safety flag pole -
Building a Dummy Load and Measuring Power Accurately by Ken, K4EAA -
Cleverscope PC based oscilloscopes, spectrum analyzers and signal generators -
The J pole vertical for 14MHz is built from a fifty-foot TV push up mast by Mike Higgins, K6AER -
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Effective HF Mobile Antennas Keith WB2VUO, explains difficulties on gaining antennas efficiency on lower bands with mobile antennas. -
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RFI Kit, ferrite cores, baluns, loop antennas, antenna tuners and various accessories -
This antenna tuner is a multi-type matching system in the same box, which includes L - Pi and T networks. -
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Lookup callsign histories & applications, available Amateur Extra callsigns, vanity callsign predictions, and more. Updated from FCC data several times a day. -
Nasa MSFC predictions on the behavior of current sunspot cycle. -
a Javascript for calculating the lengths of tubing to be used for the construction of a Super J-Pole. -
This article describes a low-cost, low-to-moderate power dummy load, which presents a 50-Ohm resistive load from HF through 440MHz. -
Product review & short takes columns from QST magazine