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A flex antenna working on 6m and 70cm by K0EMT

RTL-SDR is a very cheap software defined radio that uses a DVB-T TV tuner dongle based on the RTL2832U chipset. This is a blog about rtl-sdr, software defined radio and their developments and applications.

Ham Radio repair of all major brands and models, located in Carrollton, Texas, which is just north of Dallas, and have been serving the Amateur Radio community for over 20 years.

Make your own interface, two schematics for building an interface using the RTS line by N3UR

A 9:1 voltage unun using a T-200-2 powdered iron toroid core to feed a long wire multiband antenna.

HB9DNU Karlheinz's blog, hosted on Blogger, presents a collection of personal reflections and observations, predominantly in German. The content spans various non-amateur radio subjects, including Swiss political initiatives, economic discussions concerning banks like UBS, and social commentary. For instance, an entry from February 2008 details the Swiss vote on a combat jet noise initiative, highlighting the debate between tourism concerns and national security. Another post from October 2008 critiques the 500 billion Euro bailout package for banks, calculating its per-capita cost for German citizens and referencing earlier blog entries from March 2006 and June 2007 that discussed UBS salaries and Raiffeisenbank issues. These entries often reflect Karlheinz's personal perspective on current events. The blog also includes lighter, more personal notes, such as a February 2009 entry about a video produced by his grandson, and observations on local events like a bird exhibition in Contone or a scenic train ride through the Centovalli, demonstrating a broad range of interests beyond the ham radio hobby.

Article on a 2 and 6 meters halo antennas that does not require a mast has a very low part count and can easily be built with a minimum of tools.

ST2NH blog - first ham blog from africa fatures QRP,Homebrew,news,links

Article on various type of transmissium medium, like parallel lines, twisted pairs, shielded pairs, coax lines

Calculating Antenna Wind Load

2 meter kilowatt linear amplifier

Homebrewing a mic boom headset for the Yaesu FT 897 and 857 transceivers

K0EMT mobile antenna mast mount

Spanish ham radio shop with a complete amateur radio equipment offer

A bowtie antenna is a type of antenna that reputedly provides higher gain at lower radiation angles than a center-fed dipole antenna at heights considerably less than 1/2 wavelength above ground.

If your doing any home brewing gear for ham radio its a great idea to have a dummy load. This will to your radio be the perfect antenna...it will never radiate but your radio sees a perfect 50 Ohm impedance.

allows a Macintosh computer to communicate via packet radio with the amateur packet satellites currently in operation using the 'PACSAT' protocols

2,6 and 10 meters beacon located at Lake White, Ohio

A 50-ohm 10W resistor forms the core of this portable QRP antenna, designed by _K0EMT_ for convenient operation on 160m and 80m. The construction involves soldering the resistor to a BNC connector, with one lead to ground and the other to the center conductor, then insulating the assembly. This minimalist design aims to provide a highly portable solution for low-band QRP operations, acknowledging the inherent trade-offs between antenna size and efficiency. Testing with an antenna analyzer revealed low SWR on both 160m and 80m, with a Yaesu FT-817 confirming good matching. While 40m and 30m showed higher SWR, the primary focus remains on the lower bands. The author successfully tested the antenna with **2.5W CW** output, demonstrating its practical application for QRP field operations where ease of deployment is paramount, even if it means sacrificing some **gain** compared to full-sized antennas.

Eham IC-2100H review

An active receiving antenna for 10 KHz to 20 MHz, a very small sized antenna with excellent performances in noise to signal ratio.

Find the best placement of a mobile antenna

A Low -Power Indoor Portable HF Antenna by Monty Northrup, by N5ESE

This homemade tube oscilloscope is based on the WaterMan Pocket-Scope 0510A, a 3 tube oscilloscope made in 1946.

This program expedites the design of lumped-element diplexers using both the lowpass/highpass and the bandpass/bandstop topologies.

IC820H or other Icom Radios Soundcard interface for VHF EME use by DF9CY

Picture and specifications of the Yaesu FT-847

Develops and manufactures radios and telecommunication devices for special applications. SDR Receivers, Digital HF transmitters, Digital SSB Exciter.

This document contains the detailed instructions to build a homemade lindenblad antenna using a twin-lead as dipole elements. This document contains 9 pages and includes a detailed construction sequence and some drawings to build this antenna for UHF and VHF ham radio bands

3d parts printed to build an EZ-Lindenblad 2 Meters LEO Sat antenna as designed from Anthony Monteiro

1:1 Ruthroff voltage balun using a T200-2 Toroid core

Picture and specifications for the Icom IC-9100

SM5BSZ article on building VHF RF amplifiers

The Smith Chart was originally created many years ago as an RF engineering aid by Phillip Smith of RCA.These pages includes extesnive documentation on smith carts.

Utility program to verify, merge, and sort standard 2-line orbital elements files

A simple center-fed dipole made just with a thin-wall PVC pipe, aluminum tape, and RG-8X coax

The Peaberry SDR is the first and only do-it-yourself transceiver that doesn't require adding sound cards to your computer.

On-line Log search for 5U5R DX Pedition to Niger 2017

The KA7OEI FT-817 pages, customizing/accessorizing the FT-817

Operating a specialized DX cluster, this service provides real-time DX spots exclusively from stations confirmed to be _Log of The World_ (LoTW) users. This unique filtering mechanism allows DXers to prioritize contacts with stations that are highly likely to upload their logs to LoTW, streamlining the process of achieving confirmed DXCC or other awards. The cluster aggregates data from various sources, presenting a focused view of active LoTW participants across multiple bands. By narrowing the scope to LoTW-active stations, the platform significantly reduces the effort required for QSL management, as users can confidently pursue contacts knowing a digital confirmation is probable. This targeted approach is particularly beneficial for contesters and DXpedition chasers aiming for rapid award qualification, offering a strategic advantage in identifying viable contacts. The service supports both web-based access and traditional telnet connections, ensuring broad compatibility for amateur radio operators. It processes thousands of spots daily, with a focus on delivering accurate and timely information relevant to LoTW users, facilitating more efficient and productive operating sessions.

Homebrew a compact yagi antenna for 14 Mhz suitable for those with small plots based on a design by AB4GX

QSL Cards from ALL 338 DXCC Entities, deleted countries QSL Cards, other interesting cards

Raspberry Pi WebSDR Receiver Project running SoftRock Lite ii Receiver (40m) and Raspberry Pi Model B

A museum of thousands of telegraph keys, radios, microphones, enigma cipher machines, and scientific instruments.

The multiuser/multitasking BayCom Packet Terminal Driver program is a general purpose communications package for communicating with a BayCom modem attached to your IBM-PC/clone in conjunction with the TFPCX Baycom driver software. The software will also work with a normal TNC if it supports KISS mode, such as the Kantronics range.

YY5PER video of a Icom IC-7000 modified for TV reception

Arduino automatic CW Keyer for amateur radio

A folded dipole using twin lead By W8HDU

Garmin Kenwood Icom Vertex Alinco and more

An extension of the excellent decoding software JT65 HF by Joe W6CQZ for amateur radio digital mode JT65