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Very Low Frequency Antennas
Antennas for 1 KHz to 30 KHz

Very Low Frequency Antenna 10 KHz - 30 KHz

VLF Band antenna offers high sensitivity and narrow bandwidth.

Directional to help reduce interference when 2 stations from different directions are on the same channel.

Ideal for long range lightning detection applications at 10 KHz - 30 KHz.

For use in

  • VLF natural radio wave reception,
  • super range lightning detection,
  • geologic research,
  • EM research.

    Weather-proof plastic case.

    Binding post connections.

    Monster-size 12.3 inch long x 1.02 inch diameter ferrite rod core for maximum reception.

    Part Number: 12VLF10K30KBC is a Very Low Frequency antenna for 10 KHz - 30 KHz range, and can be user tuned with external variable capacitor user supplies. .

    If you chart plot any distant steady beacon in this band you will see a very sudden sharp drop near sunrise, as the sunlight first hits the ionosphere. This band is less sensitive to ionosphere changes, but it can still be used for various types of research.

    Signals at 10 KHz to 30 KHz can circle the globe, and super range cloud-to-ground lightning detection is possible in this range.

    Specification: (+/- 10 %): 1000 pF tunes @ 21 KHz

    Tuning Data: 0.01 uF tunes @ 10 KHz, 5000 pF tunes @ 14 KHz, 1400 pF tunes @ 18 KHz, 1000 pF tunes @ 21 KHz, 400 pF tunes @ 30 KHz.

    Part # FrequencyPrice
    12VLF10K30KBC10 KHz - 30 KHz$ 185.00

    Click Here for Data Sheet. Part Number: 12VLF10K30KBC.


    Optional variable tuning capacitor for this antenna

    NOTE: Antennas are 14 inches long.

    NOTE: These antennas are bi-directional having a 'figure 8' pattern.


    Very Low Frequency Antenna 3 KHz - 17 KHz

    VLF Band antenna offers high sensitivity and very narrow bandwidth.

    Directional to help reduce interference when 2 stations from different directions are on the same channel.

    Ideal for lightning detection applications at 3 KHz - 17 KHz.

    For use in

  • VLF natural radio wave reception,
  • super range lightning detection,
  • geologic research,
  • EM research.

    Weather-proof plastic case.

    Binding post connections.

    Monster-size 12.3 inch long x 1.02 inch inch diameter ferrite rod core for maximum reception.

    Part Number: 12VLF3K17KBC is a Very Low Frequency antenna for 3 KHz - 17 KHz range, and can be user tuned with external variable capacitor user supplies.

    Signals at 9 KHz to 17 KHz can circle the globe, and super range cloud-to-ground lightning detection is possible in this range.

    Specification: (+/- 10 %): 1000 pF tunes @ 11.5 KHz

    Tuning Data: 10,000 pF tunes @ 3.7 KHz, 5000 pF tunes @ 5.2 KHz, 1500 pF tunes @ 9.5 KHz, 1000 pF tunes @ 11.5 KHz, 400 pF tunes @ 17 KHz.

    Part # FrequencyPrice
    12VLF3K17KBC3 KHz - 17 KHz$ 185.00

    Click Here for Data Sheet. Part Number: 12VLF3K17KBC.


    Optional variable tuning capacitor for this antenna

    NOTE: Antennas are 14 inches long.

    NOTE: These antennas are bi-directional having a 'figure 8' pattern.


    Very Low Frequency Antenna 2 KHz - 7 KHz

    VLF Band antenna offers high sensitivity and very narrow bandwidth.

    Directional to help reduce interference.

    For use in

  • VLF natural radio wave reception,
  • super range lightning detection,
  • geologic research,
  • EM research.

    Weather-proof plastic case.

    Binding post connections.

    Monster-size 12.3 inch long x 1.02 inch inch diameter ferrite rod core for maximum reception.

    Part Number: 12VLF2K7KBC is a Very Low Frequency antenna for 2 KHz - 7 KHz range, and can be user tuned with external variable capacitor user supplies.

    Specification: (+/- 10 %): 1000 pF tunes @ 7 KHz

    Tuning Data: 10,000 pF tunes @ 2.7 KHz, 5000 pF tunes @ 3.7 KHz, 1000 pF tunes @ 7 KHz.

    Click Here for Data Sheet. Part Number: 12VLF2K7KBC.

    Part # FrequencyPrice
    12VLF2K7KBC2 KHz - 7 KHz$ 190.00


    Optional variable tuning capacitor for this antenna

    NOTE: Antennas are 14 inches long.

    NOTE: These antennas are bi-directional having a 'figure 8' pattern.


    VERY LOW FREQUENCY ANTENNAS
    1 KHz - 20 KHz
    700 Hz - 10 KHz

    tuned directional antenna

    For use in

  • VLF natural radio wave reception,
  • super range lightning detection,
  • meteorology,
  • geologic research,
  • EM research.

    Antennas in this range are useful for specialized remote sensing applications such as global lightning detection.

    Listen to the natural radio waves the earth makes in the 1 KHz - 20 KHz VLF range: Tweeks, Whistlers, Dawn Chorus, Risers, Hiss, Cloud-to-Ground Lightning Flashes, etc.

    Connect directly to the microphone input (sensitivity 1 mV) of any portable audio amplifier or tape recorder to hear tweeks and whistlers and lightning broadband.

    Directional to help reduce interference and zero-in on desired signal.

    MUF21 antennas feature a Mu-Metal Core for high sensitivity, broader bandwidth than ferrite core antennas.

    Antennas are cased in weather-proof PVC plastic with two binding post connections.

  • MUF21 is 24 inches long.
    VLF Antenna
    Part # Radio Band Low Freq Hi Freq __Price
    MUF21-1K-20K-BCVery Low Frequency 1 KHz 20 KHz$ 195.00
    MUF21-700H-10K-BCVery Low Frequency 700 Hz 10 KHz$ 195.00

    Click Here for Data Sheet. Part Number: MUF21-1K-20K-BC.

    Click Here for Data Sheet. Part Number: MUF21-700H-10K-BC.

    DC - 30 KHz Wideband Instrumentation Amplifier for use with these antennas.

    S/H UPS ground extra.

    TUNING DATA: MUF21-1K-20K-BC
    0.47 uF = 1 KHz.
    0.1 uF = 2.2 KHz
    0.0047 uF = 10 KHz
    1000 pF = 18.8 KHz.
    0 pF = 25 KHz.

    TUNING DATA: MUF21-700H-10K-BC:
    0.47 uF = 670 Hz.
    0.1 uF = 1.6 KHz
    0.0047 uF = 6.6 KHz
    1000 pF = 11 KHz.
    0 pF = 17 KHz.

    You can hear:

    Whistlers: 1.7 KHz - 5 KHz.
    Tweeks: 1.7 KHz - 2.5 KHz.
    Dawn Chorus: 1 KHz - 2 KHz.
    Super Range Lightning Detection: 8 KHz - 20 KHz. ( 10 KHz standard )


    How to use the antennas
    BOOST RECEPTION

    Just wrap a few turns around the antenna and connect to your radio's 50 ohm antenna input. Tune then rotate the antenna for directional reception. Hear stations without needing to put up an outdoor wire antenna. (radio for the example shown does not receive VLF, but the 50 ohm connection type is the same).

    When the antenna is tuned up, a great boost in signal strength occurs. No extra batteries or power needed for improved reception. Great for portable reception use.


    How to use with test equipment

    You can connect directly to equipment having high input inpedance (such as an oscilloscope) to receive VLF signals. Use a capacitor in parallel to tune VLF frequency. You can drive a VLF receiver having a high-Z FET front end in this manner. Do not exceed voltage input rating of equipment if testing with oscillators or nearby transmitter sources that might cause the antenna to output a high voltage past the rating of the test equipment. Use a back to back Zener diode across the antenna to clamp the voltage well below the max rating of the equipment.
    See our complete line of standard antennas:

    Antennas for Short Wave 1.7 MHz - 4 MHz
    Antennas for AM Broadcast Band 530 KHz - 1710 KHz
    Antennas for Long Wave and 30 KHz - 530 KHz
    Antennas for Very Low Frequency 3 KHz - 30 KHz
    Antennas for Ultra Low Frequency 300 Hz - 3 KHz
    Antennas for Super Low Frequency 30 Hz - 300 Hz
    Antennas for Extremely Low Frequency 0.03 Hz - 30 Hz


    Lightning Detection: Using the antennas for lightning detection and geophysical research.

    The antennas detect the magnetic field part of the radio wave for lightning detection so no other wire antenna is needed. The antennas are directional (bi-directional) so aim antenna for best reception.

  • Lightning Detection Antennas:

    Lightning Detection Band A is useful 24 hours a day. Global range possible. Lightning's power output is centered in this band allowing easy detection.

    Lightning Detection Band B is useful 24 hours a day. Extreme range possible. High lightning power in this band.

    Lightning Detection Band C is useful 24 hours a day. Long range possible. Range increases greatly at night.

    Lightning Detection Band D opens at night for very long range detections. Only short range in daytime.

    Lightning Detection Band E opens at night for very long range detections. Only short range in daytime. May have power line harmonic hum interference in this band.

    Lightning Detection Band F is useful only for detecting local cloud to ground strikes. May have power line hum noise in this band.

    Lightning Detection 'A' band properties: The 'A' band at 10 KHz to 15 KHz allows global cloud to ground lightning strikes to be monitored. Propagation is strong day and night for easy very long distance reception. Signals at 10 - 15 KHz can at times circle the globe, coming back to the point of origin as an "echo". No man-made transmissions in this band in the USA. Constant crackling of global lightning static can be heard in this band.

    Lightning Detection 'B' band properties: The 'B' band at 7 KHz to 10 KHz allows global cloud to ground lightning strikes to be monitored. The range is greater toward the top end (10 KHz) of the band. Lower range toward the bottom. Slightly better range at night time. No man made signals in this band. Constant crackling of static can be heard in this band. No man made signals in this band.

    Lightning Detection 'C' band properties: The 'C' band at 5 KHz to 7 KHz allows hemispheric lightning ground strikes to be monitored. The range is greater at night time than daytime. Static crackling is constantly heard in this band, and it increases greatly at night time as the band opens due to dissipating ionospheric "D" layer for very long range reception. No man made signals in this band.

    Lightning Detection 'D' band properties: The 'D' band at 3 KHz to 5 KHz allows hemispheric lightning ground strikes to be monitored at only night time. Range is markedly shorter during the day time, less than 75 miles. Very long range after local midnight when ionosphere "D" layer is faded. The larger strikes are heard here. Natural radio wave emissions and Whistlers (an ionospheric dispersion effect, which causes a very distant lightning strike to sound like a sliding whistle tone instead of the usual static sound) are heard in this band. Whistlers are centered around 3 KHz, but also can be lower or higher in frequency. Geomagnetic storms can cause natural radio wave emissions in this band and in bands lower in frequency. No man made signals in this band.

    Lightning Detection 'E' band properties: The 'E' band at 2 KHz to 3 KHz allows long distance lightning ground strikes to be monitored at night time, especially after midnight. Range up to 300 miles night time. Only the larger strikes are detected here. Range is markedly shorter during the daytime, less than 50 miles. No man made signals in this band, except for power line hum harmonics.

    Lightning Detection 'F' band properties: The 'F' band at 1 KHz to 2 KHz allows local lightning ground strikes to be monitored as well as signals from geomagnetic storms. Range (for lightning detection) is markedly shorter during the day time, less than 30 miles. The band opens after midnight local time for range up to 300 miles (above 1.7 KHz) for the stronger cloud-to-ground strikes. Whistlers and geomagnetic storm noise (dawn chorus and hiss noise) is heard in the lower half of this band. The Earth - Ionosphere waveguide effect does not support electromagnetic waves of a frequency lower than approximately 1.7 KHz. Range of less than 30 miles will be obtained below this frequency. A sharp contrast (at night) can be heard in the static level at 2 KHz and the static level below 1.5 KHz due to this effect. No man made signals in this band except for powerline harmonic hum. Whistlers extend down to this band. Dawn chorus (a natural radio wave emission that occurs just after dawn, especially during geomagnetic storms) is heard in this band. Dawn chorus range is from 700 Hz to 1.4 KHz.

    Lightning Detection 'G' band properties: The 'G' band at 500 Hz to 1 KHz allows local lightning ground strikes to be monitored. Range is less than 30 miles. Whistlers extend down to this band, becoming drawn out and slow sounding. Dawn chorus extends down to 700 Hz and up to 1400 Hz this band. Hiss can be heard in this band. Propagation mode is solely through the ground, water, or along earth's magnetic field lines for non-lightning signals originating more than 30 miles away.

    Other Lightning Detection Bands:

    Other bands can be used for lightning detection. These bands may have broadcasts or communications and are not used exclusive for lightning detection. Rotate the antenna to completely null any station.

    38 KHz - 56 KHz This band allows good long range detection day or night. Better range at night. Time signal beacons and utility stations may be in this band. Powerful static from storms up to 300 miles away.

    59 KHz - 61 KHz This band allows good long range detection day or night. Much better range at night. Time signal beacons and utility stations may be in this band. WWVB at 60 KHz heard in this band, aim end of antenna toward this station (located in Colorado, USA), to null it out completely for reception. Powerful lightning static in this band from storms up to 300 miles away.

    90 KHz - 110 KHz This band allows good reception of lightning static, storms emit a very high amount of power in this range. The LORAN-C navigation system has been dismantled leaving this range generally clear. Other stations may exist in this range. Rotate antenna to null out completely. Range better at night than in day.

    Hearing Whistlers and Tweeks and other natural emissions.

    These antennas allow pick up of natural radio emissions. You can tune the antenna or use it broad band. Antennas can be coupled into your tape recorder or audio amplifier to allow direct reception of natural radio waves below 5 KHz.

    This pre-amplifier example design allows direct tuning of the antennas, pre-amp does not load down the antenna's extremely high output impedance when operated in tuned mode.

    VLF / LF (Tunable) FET Pre-amplifier using field-effect transistor MPF-102 (parts from Radio Shack).

    This pre-amplifier example design allows wideband reception.

    VLF Whistler Receiver using field-effect transistor MPF-102 (parts from Radio Shack).