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Stuff about amateur (ham) radio, especially VHF/UHF, QRP, portable and mountaintop operating

This is a project aboout compact and portable a QRP antenna tuner for use in the HF ham radio bands from 3-30 MHz, even if it's a compact and efficient project this small antenna tuner will not match any possible load.

A 30 Meter, Discrete Component CW Transceiver Built Manhattan-style

The QCX 5W CW Transceiver From QRP Labs, a detailed article describing from the unboxing of the component to the final assembly of the CW QRP Transceiver

An interesting article on end fed half-wave wire antennas with a couple of original experiments. Author illustrate the role of the QRP matchbox, and a 40/20 meter antenna with a center stub making it a large bandwidth antenna for 40 and 20. Includes also an 80/40 end fed with the typical coil to make it available on 80 merts band.

Gimme Five reloaded, a compact 5 band QRP SSB transceiver in SMD technology. This unit covers 5 bands within the amateur radio spectrum (3.5, 7, 14, 21 and 28 MHz). Receiver is a single conversion unit with an interfrequency of 9 MHz. Transmitter uses 5 stages and has got a power level of 10 watts PEP output.

A tutorial on setting up a Low Cost QRP (FT8, JT9, WSPR etc) Monitoring Station with an RTL-SDR V3 and Raspberry Pi 3

A review of the Chinese version of uSDX USDR HF QRP Transceiver. Author made an extensive review of receiver and transmitter features.

An interesting article about a homemade LiFePO4 battery pack for ham radio operations, a 10Ah LiFePO4 based on Headway 38120 Cells

Dipole antennas are some of the simplest antennas to build in addition to being very efficient and solid performers. I wanted to make a simple dipole antenna for QRP portable operation that could be used on multiple bands.

A Multiband Slinky Coil for the PAC-12 portable Antenna, can be used also as a dual PAC-12 dipole by James Bennett

Schematic drawing and instructions for the construction of a simple portable dipole for use in low power and portable operations

A micro-blog about micro-signals, mostly QRP

Using portable battery power is always a challange when operatin amateur radio in sota oprations. This article is about implementing lithium iron phosphate cells (LiFePO4) in ham radio portable operations.

While there are quite a few standalone Morse Code or CW decoders out there, I wanted to tackle the problem myself and end up with both a great Arduino learning project and a decent portable decoder for when I'm out in the field operating QRP

DK7IH QRP transceiver for 14 MHz. This small and compact home made transceiver with a max power output of 5W, the VFO module is based on the clock oscillator chip Si5351A by Silicon Labs ATmega168 and OLED 1306

Online NOS electronic parts shop for QRP-QRPp radio constructors, to vintage radio and electrical measuring equipment restaurators. Many Germanium diodes, transistors and RF parts, semiconductors.

The Michigan QRP Club is full of people who love challenges and new adventures. They experiment with everything radio and learn a lot along the way.

HF propagation to your Linux desktop. CQRLOG uses data from HamQSL website provided by Paul, N0NBH.

Elecraft new QRP transceiver, an 80-10 m SSB/CW/Data station that fits in your pocket

A home made Antenna Tuner made with a simple inductor and a few spare parts. Despite the title, the author succesfully tested this ATU with higher power inputs.

Frequency agile 80 metre CW QRP transmitter. Ceramic resonators vary in the frequency shift obtainable. The one in the prototype of this article gave 3.525 to 3.558 MHz coverage.

The (tr)uSDX is a 5-Band / Mulitmode QRP Transceiver in Pocket Format (90x60x30mm - 140g). It features a highly efficient Class E PA and Supports CW/LSB/USB and AM/FM. Right now it covers 80/60/40/30/20m and in Future there will be support for 17/15/12/10m

A pocket-sized homebrew 40m CW QRPp/QRP transceiver

This device was designed as an SWR and power meter for Radio Amateurs. In addition to SWR, it measures forward and backwards power, therefore can also be used as a wattmeter. With a large measuring range from 1 to 1000 watts, it is suitable for use from QRP to QRO

Manufacturer of the TR-35 4-Band 5-Watt CW Transceiver Kit

A home made portable QRP transceiver designed to work on 40 or 80 meters SSB band.

An L-Match tuner is a device that can add either inductance (L) or capacitance (C) to the antenna, bridging that gap between 5000 ohms and 50 ohms, thus matching it to the radio. The L-Match tuner is an extremely useful device that every QRP operator will want to have.

A review with early observations and technical data specifications of the Icom IC-703 QRP HF+50 MHz transceiver

This antenna just requires about 24m of free space instead of 41m that a normal half wave 80m antenna needs to hang up. The so called loaded dipole uses a coil in every dipole arm to electrically lengthen the mechanical too short dipole arms. Every coil has an inductivity of 120 microHenry.

For my SOTA activities, i recently bought a QRP transceiver QRP SW-3B, which is a three-band QRP CW only for 40/30/20 m. So, i needed an antenna that would allow to use these 3 bands in SOTA portable activity. Already having some experience with the EFHW antenna, i decided to build one for 40/30/20m.

This is an uncommon loop antenna, hombrewed without the small feeding loop. With small spare parts is possible to build a loop antenna tuner for portable usage tha can ben used with common HF QRP transceivers

This article introduces an Arduino-based QRP CW Transceiver designed for lower HF bands. The journey begins with the Wotduino, evolving from a keyer to a multi-mode beacon. The development includes a QRP transmitter and culminates in a receiver inspired by Roy Lewallen design. The transceiver, controlled through a control bus features a signal path, modulation, filtering, and adjustable frequency settings. Despite initial testing intentions, successful QSOs on 80 and 40 meters showcase its functional capabilities.

The 1 watt 20 meter QRP transmitter with VXO. This is a nice QRP transmitter that can be used in combination of one of the simple receivers.

Optimizing the cable connections for cat control and audio input output by implementing the digirig mobile. A small audio and rig control interface, with a single USB cable supports most QRP radios requiring external audio and CAT control facilities

RF Power measurement using a DVM, RF Power measurement using an RF detector, RF Power measurement using an Oscilloscope and using a Spectrum Analyzer

Personal web site by N9SKN about portable QRP operations with pictures of several portable setups and antenna solutions.

A nice QRP, EME, satellites, VHF DX, Amateur radio blog by Lars Petersen OZ1BXM

Revision of the Cigarette Pack 14MHz SSB QRP Micro-Transceiver

Original HF magnetic loop antenna designed by the author to work in conjunction with QRP transceivers like the FT-817 in portable operations. In this configuration the loop can operate from 30 to 10 meters. Using a two spires radiator of the same diameter it also covers 40 meters.

This project details the creation of a portable GoBox housing an IC705, Windows 11 PC, and Bluetooth microphone. The robust setup, enclosed in a weatherproof Hofbauer Explorer Case, ensures stability and functionality for QRP and emergency radio activities. The aluminum-mounted devices minimize RF interference, and a built-in LifePO4 battery powers the 10.1 TFT touch LED monitor, providing approximately 12 hours of use in receive mode. With a focus on grab-and-go versatility, this GoBox stands as an efficient solution for outdoor ham radio operations.

1-watt 17-meter cw transmitter that was originally done about 10 years ago as a club project for RAMS, the Radio Amateur Megacycle Society. It uses a VXO, rather novel at the time. It also uses a bandpass filter at the output rather than the usual lowpass

A medium power End Fed Half Wave Antenna coupler, specifically tuned to the QRP frequency of 7030 kHz. Constructed from coil stock and capacitors, it achieves an impedance ratio of 64:1. The coupler has proven effective for power ranges from 2 to 100 Watts on the 40m band.

This page describes a printed circuit board that you may use to build a QRP keyer.

The UniBalun is a PCB for building a lightweight antenna transformer (Balun) or impedance converter (UnUn) for low power radios. By soldering jumpers and a toroid core, you can create a 1:1, 1:4 Balun or 1:49, 1:9 UnUn. The latest revision (1.2) includes improved pads and supports both BNC and SMA connectors. Build instructions are available for German speakers.

Tutorial, How to call CQ as an HF QRP station in SSB/Phone. Calling CQ Basics, Calling CQ QRP or Portable

A Home made antenna tuner for QRP transceivers. This small tuner is the ideal for portable operations with random length wires or whenever you have not a resonant antenna.

Notes, hints and tips on starting with morse code, how to approach learning the code, how and when to get on the air, learning and using abreviations, common Q-Codes and a sample morse code QSO.

Early pictures and presetation of the Icom the IC-705, new all bands all modes QRP transceiver introduced at Tokio HamFair on August 31st September 1st 2019.

This article explores the conventional wisdom about antenna height in amateur radio operations, challenging the common belief that "higher is always better." Through practical examples and computer modeling, it examines how low-height antennas like Beverage antennas, VP2E, and End-Fed Half Wave (EFHW) configurations can perform effectively in various scenarios. The analysis includes radiation patterns and efficiency considerations for antennas at different heights, particularly focusing on portable operations. The article demonstrates that while height affects antenna performance, lower installations can still provide practical and efficient solutions for specific applications, especially in portable and QRP operations.