This VLF Receiver detects electrostatic field radiation in the range of 100 Hz - 10 KHz. You can listen to the electrical sounds that are made by the earth, lightning, and near space sources.
The VLF Receiver requires no tuning, it picks up the whole spectrum between 100 Hz - 10 KHz and lets you listen to all of the natural VLF radio wave emissions such as tweeks, whistlers, dawn chourus, hiss, etc.
For best reception mount the receiver far away from power lines to prevent reception of hum noise.
Connect to an audio amplifier or tape recorder to make recordings of the strange electrical 'sounds' the earth makes.
The output is strong enough to drive directly a sensitive earphone or headphones.
Easy 4 wire connection: Yellow = Antenna, Green = Audio Output, Red = (+), Black = (-).
It is input protected and overload protected.
Part # VLF-A1 $ 35.00 + $ 8.00 s/h.
C1 = 10 uF capacitor.
50 feet of cable. Any kind, but recommend flat thin telephone cable similar to the type on the unit.
Ground rod: 3 foot long copper rod.
Wire the unit as shown above.
The antenna and receiver module should be mounted away from power lines, phone lines, and trees.
Connect a 5 foot long vertical wire to the yellow wire to work as the antenna. The antenna tip should be 9 feet above ground. You can support the wire inside of a piece of CPVC pipe like shown below.
Any 3 or 4 wire type cable (best to use phone wire like on the unit), can run back indoors to the receiver operating location.
Connect a ground wire to the black wire on the sensor and connect to a ground rod (a 3 foot long piece of copper pipe) driven in the ground directly under where the antenna is located. This will improve reception.
The antenna and receiver module can be placed inside of CPVC or PVC pipe fittings and clamped on to a metal pole using U-Clamps.
The 5 foot pole should be driven in the ground 1 foot for stability. Do not put this assembly on a tall pole or on your roof. Detection of home wiring power hum will result.
Do not power the VLF receiver module with a wall plug-in power adapter: Detection of house electrical noise and hum will result.
The audio output of the VLF receiver (without any extra amplification) is strong enough to drive a sensitive earphone or headphones. Use a 47 uF capacitor instead of the 10 uF the green wire which connects to the 'tip' or the end of the headphones. The ground on the headphones goes to the (-) terminal.
For highest sensitivity use a 'crystal' earphone, or use an audio transformer to match the headphones.
Output impedance of the VLF receiver is 1000 ohms.
The best time to listen for natural VLF radio waves (tweeks, whistlers, etc) is after midnight local time in the fall and winter when lightning storms are less active.
You may want to try taking the receiver portable to a location far away from power lines to obtain hum-free recordings of the natural VLF 'sounds'.