Added Info POPULAR COMMUNICATIONS Jun 1995 (v.13#10) pg. 6
What's happening on the very low frequencies? How to access radio reading services, a 24-hour source of news you can use.
POPULAR COMMUNICATIONS Aug 1995 (v.13#12) pg. 30
Transmitter and receiver to experiment with "ground communications", the radio waves that travel along or beneath the surface of the earth.
POPULAR ELECTRONICS [1] Jan 1968 (v.28#1) pg. 49
What's on the air below 500 kHz. Part 1. How long waves (600 meters and below) propagate and what can be heard below the AM broadcast band.
POPULAR ELECTRONICS [1] Feb 1980 (v.17#2) pg. 88
What's on the air below 500 kHz. Part 2. Longwave receiving equipment, antennas, and the 1750-meter experimenter's band.
POPULAR ELECTRONICS [1] Mar 1980 (v.17#3) pg. 75
Build the "Whistler" VLF (very low frequency) receiver to receive the U.S. Navy's OMEGA radio-navigation signals (10- to 14-kHz).
POPULAR ELECTRONICS [2] Jul 1989 (v.6#7) pg. 39
Build a VLF (very low frequency) transmitter and receiver to explore the world below 10 kHz. Operates up to 1/4 mile.
POPULAR ELECTRONICS [2] Jul 1990 (v.7#7) pg. 29
VLF (very-low-frequency) CW-SSB-AM receiver circuit tunes RF signals between 150 kHz and 250 kHz.
POPULAR ELECTRONICS [2] Aug 1991 (v.8#8) pg. 72
Audio amplifier circuits. (1) Bird-feeder monitor. (2) Ear protector disables amplifier if output volume exceeds a preset level. (3) Variable-frequency audio oscillator. (4) Very-low frequency whistler receiver.
POPULAR ELECTRONICS [2] Oct 1993 (v.10#10) pg. 72
Frequency converter circuits. (1) Translate WWV's 10-MHz signal to the 75-meter ham band. (2) Translate VLF signals to the 6000-kHz region.
POPULAR ELECTRONICS [2] Jul 1996 (v.13#7) pg. 62
Cruising the lowest ham bands. Receivers and antennas for tuning the LowFERS (Low Frequency Experimental Radio Station) and MedFERS (Medium Frequency Experimental Radio Station) bands which operate in the 160-190 kHz and 510-1705 kHz frequency ranges.
POPULAR ELECTRONICS [2] Feb 1997 (v.14#2) pg. 39
VLF (very-low-frequency) and LF (low frequency) ham-radio bands. (1) Simple VLF/LF-to-HF converter circuit lets you receive these bands on either 3.5 to 4 MHz or 4 to 4.5 MHz. (2) Soup up your receiver with this VLF/LF preamplifier circuit.
POPULAR ELECTRONICS [2] Mar 1997 (v.14#3) pg. 67
Build this low-band converter to tune from 3 to 300 kHz.
RADIO-ELECTRONICS Jan 1983 (v.54#1) pg. 47
Low frequency transmitter. Build this no-license-required 1-watt transmitter for operating Morse code on the 1750-meter (180 kHz) band.
RADIO-ELECTRONICS Sep 1989 (v.60#9) pg. 43, 64
Low-frequency converter is combined with a standard AM radio to hear traffic in the frequency range of 10 kHz to 550 kHz.
RADIO-ELECTRONICS Sep 1989 (v.60#9) pg. 47, 64
One-tube receiver designed especially for listening to the Navy's super-powered CW station that operates in the vicinity of 20Hz (kc), with wavelengths about 15,000 meters long. Tunes from 13 to 28 KHz. Self-contained power supply. Est. cost: $14.
RADIO-TV EXPERIMENTER Apr-May 1967 (v.22#2) pg. 46
One-tube receiver especially for eavesdropping on the Navy's super-powered CW stations that operate in the vicinity of 20 KHz (kc). Tunes wavelengths in the neighborhood of 15,000 meters.
SCIENCE & ELECTRONICS [1] Dec 1970-Jan 1971 (v.28#6) pg. 28
Listening to nature's radio. In pursuit of natural radio events (whistlers, dawn chorus, hooks, hiss, risers and tweeks) which occur at very-low frequencies (from 1 to 10 kilohertz). The construction and use of a simple receiver is described.
SCIENCE PROBE! Jul 1992 (v.2#3) pg. 87