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Operating magnetic loop antennas requires careful consideration of RF safety, particularly regarding near-field magnetic field intensity. This resource presents calculations for magnetic field strength (H-field) at various distances from a magnetic loop, emphasizing that the H-field is significantly higher than the E-field in the near-field region due to the inductive nature of the radiating element. It provides specific formulas and examples for determining safe operating distances based on power levels and loop dimensions, crucial for compliance with RF exposure limits. The analysis compares calculated H-field values against FCC and ICNIRP maximum permissible exposure (MPE) limits for controlled and uncontrolled environments. It demonstrates that even at QRP power levels (e.g., 5W), the H-field can exceed MPE limits within a few feet of the antenna, necessitating greater separation distances than often assumed for electric field considerations. The practical application of these calculations helps amateur radio operators configure their stations to ensure personnel safety and regulatory compliance when deploying compact, high-Q magnetic loop antennas.

This is not a sophisticated automatic keyer but it is lot QRP to build and to have fun operatin

A workbench instrument capable of testing transistors, diodes, FETs, usefull constructing QRP circuitry.

Small, but growing, group of amateur radio enthusiasts, most of whom are within 90 miles (and more) of Atlanta

A family of small size QRP SSB transceivers for the 15 MHz. Includes a cigarette pocket size QRP transceiver and a larger shirt-pocket transceiver.

A QRP association of amateur radio operators based in Sardinia Island Italy

The FieldComm Association, based in Central Virginia, operates as a specialized amateur radio club with a primary interest in emergency communications. Members engage in various technical aspects of radio, including digital modes, QRP operations, and DXing. The association provides a platform for hams to develop skills in field deployment and reliable communication under challenging conditions, often leveraging modern digital protocols. This organization's activities support the practical application of amateur radio for public service, emphasizing readiness and operational proficiency. Members collaborate on projects and share knowledge, fostering expertise in areas like portable station setup and efficient data transmission. The focus on emergency communications distinguishes its operational priorities from general interest clubs, aligning its efforts with community preparedness.

Building the MFJ Cub QRP transceiver kit for 20 meters band by G4ILO

Supplying Toroids, Electronic Parts and Kits to Engineers, Schools and Hobbyists. Capacitos, filters, inductors, qrp products

The QRPSPOTS.com domain, once a dedicated resource for QRP operators to share real-time DX spots, has undergone a significant transformation. Previously, it served the amateur radio community by providing a platform for DX spotting, including features like a telnet cluster, web cluster, JOTA cluster, and integration with RBN and PSK Reporter data. This functionality was specifically tailored to the QRP operating mode, allowing hams running low power to find and share contacts effectively across various bands. However, the current iteration of the website, as observed, no longer presents any amateur radio content. Instead, it displays information related to a Chinese educational institution, featuring sections like "About Us," "Talent Training," "Teaching and Research," and "International Exchange." The site also lists academic notices, enrollment information for international professional qualifications, and details about CPA and ACCA project classes. This shift indicates that the domain has been repurposed, moving away from its original ham radio utility. The Four State QRP Group, which previously sponsored the QRP Spots service, is no longer associated with the content presented on this URL.

Low Cost frequency counters and DDS VFO's for QRP and Vintage Radio's. LCD Digital Display, Frequency Counter or DDS VFO

The following are the opinions expressed by various amateurs.

QRP Popular Frequencies, where to operate in QRP mode

The direct conversion receiver described consists of only a bandpass filter, mixer IC, VFO and audio filter. With only 22 parts, this simple circuit should take a few hours at the weekend to construct.

An economical dipole for simple QRP HF homebrew rigs

A frame antenna for the 80 meters band, built to be folded and to be easy to be mounted and dismounted. This antenna is suitable for indoor and QRP use, bandwidth is just 10kHz and should be observed a proper distance while transmitting due to high voltage.

This Magnetic Longwire Balun (MLB) makes it possible to efficiently use a coaxial lead-in cable with all forms of longwires, T-forms or other types of wire antennas, without the need for an antenna tuner.

by Jim Stafford, W4QO appeared in QRP Quarterly, Fall, 2006

Download the official IC-705 RF direct sampling VHF, UHF, HF, D-Star all mode 10W QRP portable transceiver. Pre-release information in a PDF file all in English.

Attenuating output power to Yaesu FT-817 and interesting article for really QRP operations by PA1B

An 80m transceiver using just 14 parts plus crystal and earpiece

ozQRP offer a range of kits to build a complete QRP SSB transceiver

A new multi-mode QRP radio beacon built around the Arduino. The beacon started with the usual lash-up on the bench, hooking the previously reported Wotduino and DDS Shield up to a driver and a transmitter module, as previously used for the Raspberry Pi beacon

An home made FETer QRP transceiver for the 80 meters band

This is a collection of emails collected over time which indicate how to put some mods into your Sierra transceiver. Most of the mods have to do with improving the power output.

This project describes the construction of a real CW QRP keyer with a small microcontrolle

The A QRP Club is a small group of Amateur Radio enthusiasts who enjoy building, operating and (mostly) talking about Low Power radio communications, equipment and systems.

The Atmel AVR Butterfly is a credit card sized board which contains an AVR MEGA169 processor, a six character LCD display, a five way joystick navigation switch, a piezo speaker, a 3 volt lithium battery cell for power and a few other odds and ends.

This project is based around the recent HF1 QRP transceiver by Ashhar Farhan, VU2ESE. The transceiver is an interesting SSB design with wide tuning range from 0-30MHz and should cover several amateur bands. The schematic for the transceiver can be found on the Minima mail list in this post with a PDF attachment

The KnightLites QRP Association is a world wide fellowship of low power (QRP) amateur radio communications enthusiasts founded in 1996, and is coordinated through the efforts of a small group of radio amateurs located in the Research Triangle region of North Carolina in the United States.

KD5FX, 20 through 6 meters, QRP to full legal power, lightweight, easy to carry

A solar powered station by IN3AQK using a 10W solar panel charging a 12v Pb sealed battery.

Interests DXing, HF Mobile, QRP.

qrpTracker is a satellite tracking program that works on the popular and easy-to-program Arduino platform qrpTracker is meant for amateur satellite enthusiasts and computing hobbyists

A 600W 1.8 MHz to 54 MHz power linear amplifier made using rugged MRF300 transistors featuring output power between 580W and 750W depending on band, power supply: 48V, 18A typical, 20A max

A review of the chinese QRP HF transceiver X1M SSB/CW RTX

A 40 meter QRP - Transceiver by DL5NEG

Operational mode QRPp QRSS Running as an MEPT Manned Experimental Propagation Transmitter

Amateur radio kits online shop, includes Mini Touch Key, QRP HF SSB and CW transceiver kits

The New England QRP Club is where "The excitement is building...."

A 70 MHz QRP transverter project

This site was created to bring products to the QRP community that are useful, inexpensive and sometimes hard to find

Integrated PSK station for 80 & 20 meters without using a PC Pictures and diagrams by N2APB

Vasantha VU2VWN VFO controlled 40m Tansmitter schematics

A sound file collection of QRP contacts by AE5X

A Short Guide to Harmonic Filters for QRP Transmitter Output. - George Dobbs G3RJV

These are QRP rated 3 Pole Butterworth filters based on a design by K4VX, feature simplicity, almost no insertion loss, and reasonable rejection on the other ham bands.

North Texas QRP Club

TenTec 1300-Series QRP CW Transceiver Kits