Longwave

Antenna Noise and Signal Cancelling at LF - By using the signals from two antennas, controlling their relative amplitudes and controlling the phase of one of them, unwanted signal or unwanted noise can be phased out. Circuitry is described which uses the signal from a wire antenna to provide selective cancelling against the signal output from an LF loop antenna.

An easy loop for VLF - An easy VLF loop, 200Hz-20kHz reception without transformers by Renato Romero and Marco Bruno

VLF Loop Antenna - A project on building a VLF loop antenna

Longwave Home Page - The World of Radio Below 500 kHz by the Longwave Club of America

Antennas for 136kHz - A very long and exaustive documentation on building antennas for 136 khz. Includes links to antenna design software for longwave

A VLF loop by IK0VVE - This antenna was born from the demand to use a loop for vlf operations in portable posting, avoiding the aid of long wires to stretch.

Long Wave Radio - Dedicated to 136 Khz band by G3YXM includes news, links and software useful for LF working.

VLF-LF And the Loop Aerial - The article discusses the theory of loop aerials for receiving and how they reduce the level of local noise. A Loop Aerial is described suitable for use on the LF and VLF bands together with a circuit of an interface loop tuner and preamplifier. The discussion extends to the problems of amplifier noise and the advantages of tuning the loop.

A LF power amplifier - A Low Frequency (LF) RF Power Amplifier by VK5BR it operates in a linear mode and can handle CW, AM and SSB.

LF MF Antenna Tuner - W5JGV antenna tuner for 150 - 500 Khz band

Introduction to Longwave Radio - A brief introduction to longwave radio

Antennas for MF and LF - Long Waves, Short Antennas, designing antennas for MF and LF communications

136 kHz direct conversion receiver - IK2PII describe here a simple direct conversion receiver, thinked for QRSS and DFCW communications, as companion of ARGO or SPECTRAN programs.

136kHz at G3YMC - 136 kHz experience by G3YMC

136KHz portable station - 136kHz portable station project by PA4VHF, Dick

136KHz portable station - 136kHz portable station project by PA4VHF Dick

136kHz Vertical Antenna - Experimental 136kHz Vertical Antenna at G3YMC based on an old Butternut HF2V 40/80m vertical antenna

200W 136 kHz transmitter - A transmitter project for the 136 kHz band by IK2PII

A LF power amplifier - A Low Frequency (LF) RF Power Amplifier by VK5BR it operates in a linear mode and can handle CW, AM and SSB.

A long wave receiving system - A long wave receiving system using FFT software Spectrum Lab

A VLF loop by IK0VVE - This antenna was born from the demand to use a loop for vlf operations in portable posting, avoiding the aid of long wires to stretch.

Amrad LF operatoins - Lot of useful information on experiments on 136 Khz band, with antenna tips DSP infos and notes on their activity in LF.

An easy loop for VLF - An easy VLF loop, 200Hz-20kHz reception without transformers by Renato Romero and Marco Bruno

Antenna Noise and Signal Cancelling at LF - By using the signals from two antennas, controlling their relative amplitudes and controlling the phase of one of them, unwanted signal or unwanted noise can be phased out. Circuitry is described which uses the signal from a wire antenna to provide selective cancelling against the signal output from an LF loop antenna.

Antenna Noise and Signal Cancelling at LF - The fact that the phasing between a wanted signal and an unwanted signal can be different on different antennas is put to advantage. With this condition, the unwanted signal can be cancelled out by controlling amplitude and phase. The heart of the system is some form of phase control circuitry.

Antennas for 136kHz - A very long and exaustive documentation on building antennas for 136 khz. Includes links to antenna design software for longwave

Antennas for 136kHz - Extensive article on building antennas for the 136 Khz band by ON7YD

Antennas for MF and LF - Long Waves, Short Antennas, designing antennas for MF and LF communications

Build a 136 kHx TX - Two versions of a 350 and 900 W output TX for longwave by G3YXM

CEPT ERC 136 Khz Recommendation - Use of the band of 135.7-137.8 kHz by the amateur service

DK8KW Longwave Information - Useful pages of longwave operations, includes a lot of reference files, beacons list, sounds and pictures

European 135.7 - 137.8 kHz Band Plan - This is not an officially recognized band plan for the European LF allocation between 135.7 and 137.800 kHz. This plan just contains my own observations and shall help the newcomer to get some orientation on where to find what.

Experiments with a Top-loaded Vertical Aerial - Alan Melia G3NYK and Finbar O’Connor EI0CF

Frequency Calibration for Weak Signal Work - 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

Ham Radio below 9 kHz - DK8KV Longwave information

Introduction to Longwave Radio - A brief introduction to longwave radio

Keyboard Modes for 600 Meters - Evaluation of various operating modes on 600 meters

LF MF Antenna Tuner - W5JGV antenna tuner for 150 - 500 Khz band

LF Sound Gallery - Sounds from the 136 kHz band

Loading Coil for 136 kHz - Pictures of loading coils according to OK1FIG

Long Wave Radio - Dedicated to 136 Khz band by G3YXM includes news, links and software useful for LF working.

Long Wave Radio - The World of LF, by G3YXM reference site for longwave operations. Introduction to operating on 136 and 501 Khz

Longwave DXing - Longwave refers to all frequencies below the lower end of the AM broadcasting band at 540 kHz

Longwave Home Page - The World of Radio Below 500 kHz by the Longwave Club of America

Longwave Information - DK8KW Longwave Information Slow-Voice, Transmitting compressed analog Audio Signals on LF

Longwave operations - 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

Longwave Overview - Longwave operations in Germany by DF0WD/DL4YHF

Longwave Station - DF0WD DL4YHF Longwave Station include a linear transverter and antenna tuner

Low Band Monitor - The Low Band Monitor is a monthly twelve page newsletter edited by Lance Johnson, that was introduced in April of 1993. The main objective of this newsletter is to promote Low Band DXing on the 1.8, 3.5 and 7.0 mz. Amateur Radio Bands

Low Frequency operations by W3EEE - 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.

Low Frequency Transmission Modes - Article by W1TAG on operating modes used on low-banding. The 2200 meter band (135.7 - 137.8 kHz) is only 2.1 kHz wide, so voice work on SSB or AM is out. Find out the best modes on LF

LowFER MedFER HiFER - What's all this stuff about LowFERs, MedFERs and HiFERs? What Is 'Part 15?'

PARS ULF/ELF/VLF Project - Polar Aeronomy and Radio Science VLF project

PIC controlled CW BPSK beacon transmitter - A description of a simple Lowfer beacon transmitter.

Propagation on 137 kHz - Propagation in the LF-Band

R-389/URR VLF Receiver - Collins R-389/URR VLF Receiver by Don Reaves W5OR

Radio waves below 22 kHz - Exploring ULF-ELF and VLF radio band

Really Low Frequency Operating - The world below 500 kHz (The wavelength is 1500 meters or just about a mile) has a number of interesting listening and communications opportunities with possibly more to come.

RSGB HF Committee - LF Band activities section

Slow CW Sensitivity - DK8KW laboratory tests to get some indication about the ability to communicate with signals below noise level using Slow-CW.

The Longwave Club of America - Lowfers are folks who experiment with radio communications at unusually low frequencies.

ulfelf : Ulf Elf Group - Ulf Elf Group. Exploration of ULF, ELF, VLF Radio with emphasis on natural radio signals, the Schumann resonances, earthquake precursors, etc.