Longwave Radio Operations: LF, MF, VLF, and ELF Resources
Find resources for longwave radio operation, including antenna designs, propagation studies, and experimental stations for LF, MF, VLF, and ELF bands.
Longwave operation covers amateur radio activity on frequencies below 500 kHz, including the 136 kHz and 472 kHz bands. Hams experiment with unique antenna designs and weak signal modes to achieve DX contacts over vast distances. Propagation characteristics on these bands are distinct, often favoring nighttime paths and groundwave signals, presenting interesting challenges for operators.
This category provides resources for hams interested in the lower frequencies, from VLF to MF. Operators can find information on experimental stations like W1TAG, explore antenna projects for LF and MF bands, and learn about specialized receiving loops for VLF. There are also discussions on weak signal techniques and frequency calibration essential for successful QSOs on these challenging bands.
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136kHz portable station project by PA4VHF Dick -
Lot of useful information on experiments on 136 Khz band, with antenna tips DSP infos and notes on their activity in LF. -
Long Waves, Short Antennas, designing antennas for MF and LF communications -
Useful pages of longwave operations, includes a lot of reference files, beacons list, sounds and pictures -
An unofficial European LF band plan for 135.7-137.8 kHz, based on observations by DK8KW, aiding newcomers in frequency orientation. -
Accurate calibration of your receiver and sound card is necessary for good results with the weak signal modes in use at LF. Modern receivers with master oscillators that are synthesized to provide all conversion frequencies greatly simplify the process. This article describes a method of making the necessary measurements and adjustments to an ICOM R75 receiver and a sound card, using the ARGO software -
DK8KV Longwave information -
Evaluation of various operating modes on 600 meters -
W5JGV antenna tuner for 150 - 500 Khz band -
Sounds from the 136 kHz band -
Pictures of loading coils according to OK1FIG -
The World of LF, by G3YXM reference site for longwave operations. Introduction to operating on 136 and 501 Khz -
The World of Radio Below 500 kHz by the Longwave Club of America -
In the VLF portion of the spectrum it is easy to listen to the emissions created by the Earth itself. These emissions are generated by many different mechanisms and are often beautiful to listen to. Coverage on LF and MF frequencies -
A squint at the world of LF This website was initially thrown together to provide ready availability to data being collected from the measurement of a transatlantic LF (Low Frequency) path. -
W1TAG details low-frequency (LF) transmission modes for the 2200-meter band (135.7-137.8 kHz), covering CW, QRSS, DFCW, BPSK, WOLF, PSK, FSK, JASON, MSK -
What's all this stuff about LowFERs, MedFERs and HiFERs? What Is 'Part 15?' -
Database of 17,000+ NDBs, Ham Beacons, Navtex, DGPS and Utility stations received at over 1,200 locations worldwide -
A description of a simple Lowfer beacon transmitter. -
Exploring ULF-ELF and VLF radio band -
DK8KW laboratory tests to get some indication about the ability to communicate with signals below noise level using Slow-CW. -
Discussion group dedicated to those who enjoy monitoring radio frequencies in the VLF radio spectrum and slightly below the VLF spectrum (3-30 KHz). -
Experimental Stations Run by W1TAG WD2XES has been used to study LF antenna design, propagation and communication modes. Signals from WD2XES have been copied as far away as Russia. -
WD2XSH Experimental Station (505 - 510 KHz) WD2XKO Transmitting Station Stanfield,NC operating between 135.7 to 137.8 KHz. -
Experimental Longwave Transmissions from Tower Hill wayland Massachusetts Operator Name Warren, Ham Call K2ORS, Frequency: 137.7796 KHz -
IK2PII describe here a simple direct conversion receiver, thinked for QRSS and DFCW communications, as companion of ARGO or SPECTRAN programs. -
136 kHz experience by G3YMC -
A transmitter project for the 136 kHz band by IK2PII -
Longwave refers to all frequencies below the lower end of the AM broadcasting band at 540 kHz -
DK8KW Longwave Information Slow-Voice, Transmitting compressed analog Audio Signals on LF -
An overview of longwave (LF) amateur radio operations in Germany, detailing the band plan, station setup, and DX results from DF0WD/DL4YHF. -
DF0WD DL4YHF Longwave Station include a linear transverter and antenna tuner -
Detailed analysis of 137 kHz LF propagation, covering ground wave and sky wave mechanisms, field strength predictions, and solar activity effects.