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VHF and VHF amplifiers including repeater rf amplifiers

Delta Loop Antenna for 15m band. This antenna is made for operating from outdoors, mainly from mobile shack. Drive to a parking you like, then build it up. Just half an hour later, you can enjoy slightly better gain than normal dipole.

Presents a catalog of **QRP** transceivers, antenna tuners, and related accessories for amateur radio operators. The product line includes the ZM-2 antenna tuner, designed for efficient impedance matching across HF bands, and the NW-series QRP transceivers, offering low-power CW operation. Additionally, the site details various ladder line insulators and specialized connectors, emphasizing robust construction for field deployment and home station use. Each product listing provides specifications, operational parameters, and pricing information. Compares the features of different **QRP transceiver** models, such as the NW-40 and NW-20, highlighting their respective band coverage and power output capabilities. The ZM-2 tuner's performance is detailed with typical SWR reduction figures for various antenna types, demonstrating its utility for portable and fixed stations. Customer testimonials and product images illustrate the practical application and build quality of EMTECH's offerings, providing insights into their durability and ease of integration into existing amateur radio setups.

This PDF document provided by AT technologies explains how to build the K9AY loop receiving antenna.

World time zones map with current time

The cobweb antenna it is basically a 5 band antenna comprising of 5 full half wave dipoles for each band - between 10 meters and 20 meters, the antenna is also resonant on 6M and can be modeled even for VHF frequencies.

Lyle Koehler's article on remote use of LF loop antennas for receiving purposes.

A simple dual band VHF UHF jpole antenna Projects by Dale Kubichek

Benefits and limitations of an end feed antennas. By Peter Parker VK3YE - first appeared in Amateur Radio, June 1998

This antenna is easy to build and suitable for broadband work, satellite work and terrestrial work.

There are many incorrect ideas and claims surrounding end-fed vertical antennas (like the I-Max 2000), end fed horizontal antennas, Zepp, and J-pole antennas. This article describes it.

This improved multiband trap dipole introduces a new trap design and a change in trap location. The antenna features double-coaxial-cable-wound traps having lower reactance and a higher quality factor (Q) than earlier coax-cable traps by W8NX

CW Skimmer 2.1 employs a high-sensitivity CW decoding algorithm based on Bayesian statistics, enabling simultaneous decoding of up to 700 CW signals within a receiver's passband on a 3-GHz P4 system when paired with a wideband receiver. The software features a fast waterfall display with sufficient resolution for visual Morse Code interpretation, automatically extracting and labeling callsigns on the waterfall traces. Extracted callsigns are exported as DX cluster spots via an integrated Telnet cluster server. The application includes a DSP processor with a noise blanker, AGC, and a variable-bandwidth CW filter, alongside an I/Q Recorder and player. It supports both 3 kHz radio passbands and wideband SDR receivers like SoftRock, RF Space SDR-IQ/SDR-14, SRL QuickSilver (QS1R), HPSDR Mercury, and Microtelecom Perseus. System requirements specify Windows XP/7/8/10 (32-bit or 64-bit), a Pentium-4 2.5 GHz for wideband operation or 1 GHz for 3-kHz radios, a COM port for CAT control, and a stereo sound card supporting 48 kHz sampling. It integrates with Elecraft KX3, Icom IC-7300/IC-7610, and Flex 6000 series radios, with documentation available for various setup configurations.

morse code machine to learn cw transmission

Manufacturer of big power amplifiers

Strong RF HF power amplifiers made in europe ! Output 2,5KW 4KW PEP, 160m to 10m.

A bazooka antenna project for the 7 Mhz, includes dimension for to homebrew your own bazooka for HF bands

Antennas cover the RF spectrum from kilohertz to gigahertz and support countless mission critical military, air-sea navigation, ILS and voice-data communications applications.

This project details three variants of a vertical half-wave antenna design for the 4-meter (70MHz) amateur radio band. The antennas use end-feeding with a parallel-tuned circuit for impedance matching to 50-ohm coaxial cable. The first variant uses suspended flexible wire for portable use, the second employs a fiberglass rod with internal wire for permanent outdoor installation, and the third utilizes aluminum tent poles for quick mobile deployment. Despite the narrow bandwidth of the matching circuit, this suits the narrow 4m FM allocation well. The design offers an effective omnidirectional radiation pattern and can be constructed with readily available materials.

Radio control software for the Macintosh

TCUBE is a combination of a Spectrum Analyzer and a Two Tone Generator, with optional quadrature outputs. It can be used for measuring the intermodulation behavior of an audio circuit, and as a general purpose tool

Some tens of very special audio files recorded during amateur radio activities like aurora traffic, meteor scatter, communications with ISS crew and the sound of various transmission modes that you can hear on HF and VHF bands

5 Elem. yagi for 10 meters, 9 element yagi beam antenna for six meters band by ON4ANT

HF Vertical and Beam Antennas, antennas accessories by Butternut. Bencher is out ouf ham radio business. Recently company products has been sold to Vibroplex and DX Engenieering.

Listen to live scanner traffic from Santa Barbara, CA for Police, Fire, EMS, Sheriff, CHP.

Import-Export Worldwide shipment of Radio-scanners, shortwave-receivers and more. Wholesale and retail-trade

10 meters band aluminum 2-Element Moxon rectangle

Ham Log book is written in MS Access. A good logging program that is very easy to use by Kevin Rea K6REA

Manual for R7, 10 12 15 16 20 30 40 meters band antenna

A homebrew project of a quadruple helix antenna system based on G3RUH 16 turn helix antenna for 2.4 GHz.

Schematics, mechanical drawings and picture of a Receiving loop antenna by N5ESE - N5FC

HF Ham Radio antennas for apartments and methods of shortening antennas

Homebrew a vertical dipole for 28 Mhz by N2UHC

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.

BiQuad 802.11b Antenna 11dBi, wide band by Trevor Marshall

Maritime frequencies and nets

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.

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.

Australian dealer, HF linear amplifiers, power supplies, baluns, HF UHF yagis and verticals including multiband HF verticals.

An easy to make trap dipole antenna for 40 and 20 meters

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

Four band lightweight antenna, that rolls up into an small Grundig antenna case by N0LX

KD6WD introduce moxon rectangles, and in particular explains how he built a moxon antenna for 15 17 and 20 meters band with excellent pictures

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.

Large picture and technical specifications by rigpix

An antenna for the 2-meter band, made by sliding coax insulator braid over a glass fiber bicycle safety flag pole