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Low Frequency Antennas

We have the high performance low frequency antenna that you've been looking for!

Specializing in antennas for reception applications below 530 KHz:

  • Antennas for Long Wave, and Navigation Beacon band: 150 KHz - 530 KHz.
  • Antennas for LF low frequency band: 30 KHz - 300 KHz.
  • Antennas for VLF very low frequency band: 3 KHz - 30 KHz.
  • Antennas for ULF ultra low frequency band: 300 Hz - 3 KHz.
  • Antennas for SLF super low frequency band: 30 Hz - 300 Hz.
  • Antennas for ELF extreme low frequency band: 0.1 Hz - 30 Hz.
  • ELF Antennas for detecting earthquakes, ground vibrations.
  • Antennas for lightning detection.
  • SCROLL DOWN to see different antenna types for individual radio frequency bands below on this page.
    Extreme Low Frequency Antennas
    0.03 Hz - 30 Hz

    tuned directional antenna

    Features a greater capture area and a larger diameter mu core and has a weather-proof plastic case with binding post connectors.

    For use in

  • seismographs,
  • magnetic motion sensors,
  • ELF reception,
  • pipeline inspection gauge pig transmitter sensors,
  • geologic research,
  • geomagnetic storm detection,
  • remote geomagnetic field mapping,
  • ferrious metal detection,
  • remote vehicle detection,
  • EM research.

    Antennas in this range are useful for geologic research and specialized remote sensing applications.

    The antenna will output a varying DC voltage (in millivolts) when moved through earth's magnetic field, or if earth's magnetic field moves, as happens during a geomagnetic storm.

    Research applications include: Seismology, Geophysics, Meteorology, Mineral Exploration, Remote Vehicle Detection, GeoMagnetic Field Mapping, Remote Ferrious Metal Detection, Vehicle Detection, etc.

    These antennas are also useful in making seismographs that have no moving parts for detection of earthquakes by using the earth's magnetic field. Any movement of the antenna thru earths magnetic field (due to ground motion during an earthquake) outputs a proportional voltage and current AC waveform in relation to earthquake ground motion.

    Antennas are cased in weather-proof PVC plastic.

  • MU22 antennas are 24 inches long and 2 and 5/8ths inches diameter.

    FE22T features a 22 inch x 0.84 inch ferrite rod core. High sensitivity, lower cost.

    MU22-A features a 22 inch x 0.5 inch mu-metal rod core. Excellent sensitivity, lowest weight. Weighs under 15 pounds.

    MU22-B features a 22 inch x 0.76 inch mu-metal rod core. Thicker rod core for greater sensitivity.

    MU48-C features a 48 inch x 0.76 inch mu-metal rod core. Highest sensitivity, greatest capture area.
    ELF Antenna
    Part # Radio Band Low Freq Hi Freq __Price
    FE22T-03H-30H-BCExtreme Low Frequency 0.03 Hz 30 Hz$ 395.00
    MU22-A-03H-30H-BCExtreme Low Frequency 0.03 Hz 30 Hz$ 695.00
    MU22-B-03H-30H-BCExtreme Low Frequency 0.03 Hz 30 Hz$ 1395.00
    MU48-C-03H-30H-BCExtreme Low Frequency 0.03 Hz 30 Hz$ 1995.00

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

    S/H UPS ground extra.

    U.S.A. only. No Foreign Orders.


    SUPER LOW FREQUENCY ANTENNAS

    SLF antenna for 30 Hz to 300 Hz.

    tuned directional antenna
  • "AF22T" Antennas are 24 inches long and 2 and 5/8ths inches diameter. Features a 22 inch ferrite antenna.
  • Part Number AF22T-30H-300H features a 22 inch x 0.845 inch ferrite rod core for narrow bandwidth and highest Q.

    Part Number ES22T-30H-300H features a 22 inch x 0.625 inch silicon steel rod core for narrow bandwidth and high Q.

    Part Number MU22-30H-300H features a 22 inch x 0.5 inch Mu Metal core for increased performance and wider bandwidth lower Q.

    Antennas in this range are useful for geologic research and specialized remote sensing applications.

    Research applications include: Seismology, Geophysics, Meteorology, Mineral Exploration,

    SLF Antennas
    Part # Radio Band Low Freq Hi Freq __Price
    AF22T-30H-300H-BCSuper Low Frequency 30 Hz 300 Hz$ 310.00
    ES22T-30H-300H-BCSuper Low Frequency 30 Hz 300 Hz$ 325.00
    MU22-30H-300H-BCSuper Low Frequency 30 Hz 300 Hz$ 535.00

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

    Click Here for Data Sheet. Part Number: AF22T-30H-300H-BC
    C = 3.3 uF for @ 30 Hz.
    C = 0.022 uF for @ 360 Hz.

    Click Here for Data Sheet. Part Number: MU22-30H-300H-BC
    C = 3.3 uF for @ 30 Hz.
    C = 0.047 uF for @ 300 Hz.
    C = 0.022 uF for @ 430 Hz

    Antennas have +/- 15% tolerance for all frequency, impedance, and resistance values given in data sheets or table below. Specifications subject to change without notice

    U.S.A. only. No Foreign Orders.

    For experimental and research applications.


    ULTRA LOW FREQUENCY ANTENNAS
    300 Hz - 1 KHz

    Length = 24 inches.

    tuned directional antenna
  • "SER22T" Antennas are 24 inches long and 2 and 5/8ths inches diameter. Features a 22 inch ferrite antenna.
  • Antennas for receiving natural radio wave emissions between 300 Hz to 1 KHz.

    Part Number SER22T-320H-1000H-BC features a 22 inch x 0.845 inch ferrite rod core for narrow bandwidths and highest 'Q').

    Part Number ES22-300H-1000H-BC features a 22 inch x 0.625 inch silicon steel rod core for narrow bandwidths rugged use and high 'Q'.

    Part Number MU22-300H-1000H-BC features a 22 inch x 0.5 inch solid Mu Metal rod core for wider bandwidth lower 'Q' and rugged use.

    Data Sheet 1

    ULF Antennas
    Part # Radio Band Low Freq Hi Freq __Price
    SER22T-320H-1000H-BCUltra Low Frequency. 320 Hz 1000 Hz $ 195.00
    ES22T-300H-1000H-BCUltra Low Frequency. 300 Hz 1000 Hz $ 225.00
    MU22-300H-1000H-BCUltra Low Frequency. 300 Hz 1000 Hz $ 435.00

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

    TUNING DATA: SER22T-320H-1000H-BC:
    C = 0.47 uF for @ 320 Hz.
    C = 0.047 uF for @ 1000 Hz.

    Click Here for Data Sheet. Part Number: MU22-300H-1000H-BC

    TUNING DATA: MU22-300H-1000H-BC:
    C = 1.0 uF for @ 200 Hz.
    C = 0.47 uF for @ 300 Hz.
    C = 0.22 uF for @ 460 Hz.
    C = 0.047 uF for @ 1100 Hz.
    C = 0.022 uF for @ 1800 Hz.

    Sales to USA and Canada only.


    Universal VLF Antennas 3 KHz - 90 KHz
    tuned directional antenna

    These compact portable VLF antennas offer high sensitivity and narrow bandwidth.

    Weather-proof plastic case.

    Binding post connections.

    Part Number: 8T-3K-90K is a universal VLF antenna for 3 KHz - 90 KHz, and can be user tuned with external fixed value capacitor user supplies. Specification: (+/- 5 %), 500 pF tunes @ 60 KHz. Operates either series or parallel resonant. High Q narrow bandwidth when tuned. Excellent for tuning WWVB 60 KHz and other VLF beacons.

    Part Number: 22T-3K-90K is a universal VLF antenna for 3 KHz - 90 KHz. 24 inches long. Can be user tuned with external fixed value capacitor user supplies. Specification: (+/- 5 %), 500 pF tunes @ 60 KHz.

    Part # FrequencyPrice
    8T-3K-90K3 KHz - 90 KHz$ 125.00
    22T-3K-90K3 KHz - 90 KHz$ 175.00

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

    Shipping/Handling extra. Ships via US mail, except for 22T which ships via UPS ground.

    Sales to USA only.

    NOTE: 8T Antennas are 11 inches long.

    NOTE: 22T Antennas are 24 inches long.

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

    NOTE: Sensitive from the broadside, not sensitive in the directions the ends face.


    AM Broadcast Band Antenna 530 - 1710 KHz

    AM Band antenna offers high sensitivity and narrow bandwidth across the full AM band.

    Weather-proof plastic case.

    Binding post connections.

    Ideal for receiving your one favorite AM station.

    Massive 12 inch long x 1 inch diameter ferrite rod core for maximum reception.

    Part Number: 12AM55BC is a universal AM antenna for 530 KHz - 1710 KHz, and can be user tuned with external fixed value capacitor user supplies.

    Specification: (+/- 5 %), 500 pF tunes @ 530 KHz, 80 pF tunes @ 1710 KHz.

    Part # FrequencyPrice
    12AM55BC530 KHz - 1710 KHz$ 150.00

    Sales to USA only.

    NOTE: 12AM55BC Antennas are 14 inches long.

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

    NOTE: Sensitive from the broadside, not sensitive in the directions the ends face.


    Long Wave Band Antenna 150 KHz - 300 KHz

    Long Wave Band antenna offers high sensitivity and narrow bandwidth across the full band.

    Weather-proof plastic case.

    Binding post connections.

    Massive 12 inch long x 1 inch diameter ferrite rod core for maximum reception.

    Part Number: 12LW55BC is a universal Long Wave antenna for 150 KHz - 300 KHz, and can be user tuned with external fixed value capacitor user supplies.

    Specification: (+/- 5 %), 1000 pF tunes @ 150 KHz. 275 pF tunes @ 300 KHz.

    Part # FrequencyPrice
    12LW55BC150 KHz - 300 KHz$ 150.00

    Sales to USA only.

    NOTE: 12LW55BC Antennas are 14 inches long.

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

    NOTE: Sensitive from the broadside, not sensitive in the directions the ends face.


    Lightning Detection Antennas
    tuned directional antenna

    These compact portable VLF antennas offer high sensitivity.

    Series Resonant Antennas factory tuned to selected frequencies.

    Weather-proof plastic case.

    Binding post connections.

    Lightning Detection Antennas: Factory tuned to selected frequency: Specification: (+/- 10 %).

    Part # FrequencyPrice
    8T-16KHz16 KHz$ 125.00
    8T-14KHz14 KHz$ 125.00
    8T-12KHz12 KHz$ 125.00
    8T-10KHz10 KHz$ 125.00
    8T-8KHz8 KHz$ 125.00
    22T-16KHz16 KHz$ 175.00
    22T-14KHz14 KHz$ 175.00
    22T-12KHz12 KHz$ 175.00
    22T-10KHz10 KHz$ 175.00
    22T-8KHz8 KHz$ 175.00

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

    Shipping/Handling extra. Ships via US mail, except for 22T which ships via UPS ground.

    Sales to USA only.

    NOTE: 8T Antennas are 10 inches long.

    NOTE: 22T Antennas are 24 inches long.

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

    NOTE: Sensitive from the broadside, not sensitive in the directions the ends face.

    NOTE: Series Resonant: Lowest Impedance at resonant frequency.

    NOTE: 8 KHz - 16 KHz. Lightning static at these frequencies can circle the globe under excellent propagation conditions.


    MINI ANTENNAS for 30 Hz - 300 KHz

    Useful as antennas and in tuned frequency selection circuits, and filters.
    Part # SRF50 pF350 pF 1000pF 4000pF 0.047uF0.1 uF 0.47uF1.0 uF 3.3 uF10 uF 47 uFPrice
    78-175-30375 KHz350 KHz190 KHz120 KHz
    67 KHz.
    -
    -
    -
    -
    -
    -
    -
    $ 25.00
    78-350-30132 KHz
    -
    -
    56 KHz 31.4 KHz. 9 KHz6 KHz
    -
    -
    -
    -
    -
    $ 25.00
    78-525-3085 KHz
    -
    -
    37 KHz 20.4 KHz. 6 KHz4.2 KHz1.9 KHz
    -
    -
    -
    -
    $ 25.00
    78-700-3067 KHz
    -
    -
    28 KHz 15.3 KHz.4.6 KHz3.2 KHz1.5 KHz
    -
    -
    -
    -
    $ 25.00
    78-875-3058 KHz
    -
    -
    23 KHz 12.3 KHz. 3.7 KHz2.5 KHz1.2 KHz800 Hz
    -
    -
    -
    $ 25.00
    78-1050-3052 KHz
    -
    -
    19.8 KHz10.4 KHz 3.1 KHz2.1 KHz1.0 KHz680 Hz370 Hz
    -
    -
    $ 25.00
    78-1225-3046 KHz
    -
    -
    17.2 KHz9.0 KHz 2.6 KHz1.8 KHz 900 Hz575 Hz 310 Hz
    -
    -
    $ 25.00
    78-1400-3041 KHz
    -
    -
    15.1 KHz7.9 KHz 2.3 KHz1.6 KHz 750 Hz510 Hz 270 Hz 160 Hz
    -
    $ 26.00
    78-2400-3028 KHz
    -
    -
    9.2 KHz4.7 KHz 1.4 KHz960 Hz 450 Hz310 Hz165 Hz97 Hz
    -
    $ 27.00
    78-3500-3318 KHz
    -
    -
    -
    3 KHz 900 Hz620 Hz300 Hz200 Hz100 Hz57 Hz
    -
    $ 28.00
    78-4500-3315 KHz
    -
    -
    -
    2.4 KHz710 Hz490 Hz231 Hz156 Hz 82 Hz49 Hz
    -
    $ 30.00
    78-6500-3312 KHz
    -
    -
    -
    1.6 KHz500 Hz295 Hz160 Hz110 Hz58 Hz34 Hz16 Hz$ 32.00
    78-8125-3311 KHz
    -
    -
    -
    1.4 KHz400 Hz276 Hz 130 Hz89 Hz48 Hz 28 Hz 13 Hz$ 35.00

    Shipping/Handling extra. Ships via US mail.

    Sales to USA only.

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

    NOTE: Antennas are 4 inches long. ELF antennas are larger diameter than unit shown in photo.

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

    NOTE: Sensitive from the broadside, not sensitive in the directions the ends face.

    NOTE: Works either series resonant (low z) or parallel resonant (high z). External capacitor is user supplied.

    NOTE: Table above shows tuned frequency in KHz or Hz when external capacitor value is used in parallel or series with the antenna.

    NOTE: GREEN color in table indicates antenna has best performance at this frequency and above.

    NOTE: PINK color in table indicates antenna has wider bandwidth and lower performance at this frequency and below.

    NOTE: SRF is the highest possible frequency the antenna can operate at, but it is recommended operating below this value using the minimuim and maximum capacitor values shown.

    NOTE: Table shows user-supplied capacitor values needed to tune the antennas to frequencies shown.

    NOTE: Frequency Tolerance Specifications: +/- 20 %.

    NOTE: The ( - ) lines in the table indicate that the antenna is not for use with that capacitor value.

    NOTE: Highest and lowest capacitor values and highest and lowest frequency working ranges are indicated in the table.


    VERY LOW FREQUENCY ANTENNA
    1 KHz - 30 KHz

    Series Resonant VLF antenna for 1 KHz - 30 KHz

    Length = 24 inches.

    tuned directional antenna
  • "SER22T" Antennas are 24 inches long and 2 and 5/8ths inches diameter. Features a 22 inch ferrite antenna.
  • Series Resonant Antenna. Test Frequency: 30 KHz when external tuning capacitor value = 384 pF. Use a larger value capacitor to tune down to 1 KHz.

    Data Sheet 1
    Very Low Frequency Antennas
    Part # Radio Band Low Freq Hi Freq __Price
    SER22T-1K-30K-BCVery Low Frequency. 1 KHz 30 KHz $ 165.00

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

    Build this sensitive 4-transistor VLF-LF Radio Receiver for 10 KHz - 300 KHz.

    TUNING DATA:
    C = 384 pF for @ 30 KHz. ( Communications between 18 - 30 KHz ).
    C = 960 pF for @ 19 KHz. ( Communications between 18 - 30 KHz ).
    C = 3000 pF for @ 10 KHz. ( Global Lightning Detection ).
    C = 0.0047 uF for @ 8.5 KHz. ( Lightning Detection ).
    C = 0.01 uF for @ 6 KHz. ( Whistlers, Natural EM emissions, Lightning Detection ).
    C = 0.022 uF for @ 4.1 KHz. ( Whistlers, Natural EM emissions ).
    C = 0.039 uF for @ 3.1 KHz. ( Whistlers, Natural EM emissions ).
    C = 0.047 uF for @ 2.8 KHz. ( Whistlers, Chorus, Natural EM emissions ).
    C = 0.1 uF for @ 1.9 KHz. ( Tweeks, Chorus, Whistlers, Natural EM emissions ).
    C = 0.22 uF for @ 1.3 KHz. ( Chorus, Natural EM emissions ).
    C = 0.47 uF for @ 0.87 KHz. ( Chorus, Natural EM emissions ).
    C = 1.0 uF for @ 0.59 KHz. ( Chorus, Natural EM emissions ).

    Sales to USA and Canada only.


    VERY LOW FREQUENCY WHISTLER ANTENNA
    1 KHz - 5 KHz

    VLF antennas for 1 KHz - 5 KHz.

    Length = 24 inches.

    tuned directional antenna
  • "SER22T" Antennas are 24 inches long and 2 and 5/8ths inches diameter. Features a 22 inch ferrite antenna.
  • Series Resonant Antenna. Test Frequency: 5 KHz when external tuning capacitor value = 0.01 uF Use a larger value capacitor to tune down to 1 KHz.

    Antenna for receiving natural radio wave emissions, such as Whistlers, Tweeks, Chorus, and other natural EM emissions in the range of 1 KHz - 5 KHz.

    Data Sheet 1
    VLF Whistler Antennas
    Part # Radio Band Low Freq Hi Freq __Price
    SER22T-1K-5K-BC Very Low Frequency. 1 KHz 5 KHz $ 165.00

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

    Part Number SER-22T-1K-5K-BC has a 22 inch x 0.845 inch ferrite rod core for narrow tuned bandwidths and highest 'Q'.

    TUNING DATA:
    C = 0.01 uF for @ 5.0 KHz. ( Whistlers, Natural EM emissions ).
    C = 0.022 uF for @ 3.3 KHz. ( Whistlers, Natural EM emissions ).
    C = 0.047 uF for @ 2.2 KHz. ( Whistlers, Tweeks, Chorus, Natural EM emissions ).
    C = 0.1 uF for @ 1.6 KHz. ( Tweeks, Chorus, Whistlers, Natural EM emissions ).
    C = 0.22 uF for @ 1.0 KHz. ( Chorus, Natural EM emissions, Whistlers ).

    U.S.A. only. No Foreign Orders.


    SEISMOGRAPH COIL
    Detect Earthquakes

    Detect earthquakes with this sensor coil. Operates in the range of 0.1 Hz to 30 Hz.

    Use this coil to build a seismograph to detect earthquakes. Its easy: Build the Bucket Seismograph 4.

    4 inch long plastic case.

    Part number 78-9125-33. $ 35.00 + $ 8.00 s/h US Mail Priority.

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

    Sales to USA only.


    EARTHQUAKE DETECTION ANTENNA
    Seismograph Pickup Antenna

    Detect earthquakes with this ELF seismograph antenna. Operates in the range of 0.1 Hz to 300 Hz.

    Build a new seismograph or upgrade your seismograph to extreme sensitivity.

    We installed this ELF sensor antenna in our bucket seismograph on 12-20-2015, and the increase in sensitivity is over 5 times greater than the previous unit. We also changed the salt water dampening liquid to light weight oil at the same time (which can have an effect of dropping sensitivity down somewhat), and even so the response is amazingly greater than the previous model antenna. Background local seismic noise can be detected with this new sensor. Update your seismograph now with this new powerful sensor antenna!

    Use this antenna to build a seismograph to detect earthquakes. Its easy: Build the Bucket Seismograph 3.

    Features a solid 6 inch Mu Metal Core for extreme magnetic sensitivity. 7 inch long plastic case.

    Data Sheet for part number 6MU-1H-300H

    For use in

  • seismographs,
  • ferrious metal detection,
  • remote vehicle detection.

    Part number 6MU-1H-300H. $ 89.95 + $ 8.00 s/h US Mail Priority.

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

    Sales to USA and Canada only.

    View earthquakes recorded with seismograph antenna.


    Miniature Very Low Frequency Antenna

    ANTM1. This 6.5 inch long antenna can be tuned from 3 KHz to 39 KHz with an external capacitor value of 0.1 uF to 384 pF. @ 350 pF tunes to @ 39 KHz. 0.1 uF tunes to @ 3 KHz.

    Weather proof sealed. 6 inch wire leads. Great for series resonant use in small transmitters or receivers. 1 watt max.

    $ 30.00 + s/h.

    Sales to USA and Canada only.

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


    Low Frequency Antenna WWVB 60 KHz.

    ANTM2. This 6.5 inch long antenna can be tuned from 30 KHz to 90 KHz with an external capacitor value of 100 pF to 3000 pF. @ 350 pF tunes to 60 KHz. Great for series resonant use in small receivers.

    Weather proof sealed. 6 inch wire leads.

    $ 30.00 + s/h.

    Sales to USA and Canada only.


    Longwave Antenna

    ANTM3. This 6.5 inch long antenna can be tuned from 150 KHz to 300 KHz with an external capacitor value of 100 pF to 384 pF. @ 350pF tunes to 150 KHz. Great for series resonant use in small transmitters or receivers. 1 watt max.

    Weather proof sealed. 6 inch wire leads.

    $ 30.00 + s/h.

    Sales to USA and Canada only.


    Longwave Antenna

    ANTM9. This 6.5 inch long antenna can be tuned from 180 KHz to 500 KHz with an external capacitor value of 100 pF to 384 pF. @ 350 pF tunes to 180 KHz. Great for series resonant use in small transmitters or receivers. 1 watt max.

    Weather proof sealed. 6 inch wire leads.

    $ 30.00 + s/h.

    Sales to USA and Canada only.


    Longwave Antenna

    ANTM10. This 6.5 inch long antenna can be tuned from 250 KHz to 530 KHz with an external capacitor value of 100 pF to 384 pF. @ 350 pF tunes to 250 KHz. Great for series resonant use in small transmitters or receivers. 1 watt max.

    Weather proof sealed. 6 inch wire leads.

    $ 30.00 + s/h.

    Sales to USA and Canada only.


    AM Radio Band Antenna

    ANTM4. This 6.5 inch long antenna can be tuned from 530 KHz to 1700 KHz with an external capacitor value of 10 pF to 384 pF. @ 384 pF tunes to 520 KHz. Great for series resonant use in small transmitters or receivers. 1 watt max.

    Weather proof sealed. 6 inch wire leads.

    $ 30.00 + s/h.

    Sales to USA and Canada only.


    WWVB Clock Antenna. 60.0 KHz.

    These 7 inch long antennas are factory pre-tuned. Series resonant. 6 inch wire leads. Weather proof sealed. For single frequency 60 KHz receivers.

    $ 30.00 each + s/h.

    Sales to USA and Canada only.
    Part number: 7SR-60.0 KHz.

    Data Sheet pdf


    VLF Lightning Detection Antennas.
    6.5 KHz, 8.2 KHz, 10.0 KHz, 12.8 KHz, and 40.0 KHz.

    These 7 inch long antennas can be used to detect lightning flashes up to 300 miles away. Series resonant. Factory pre-tuned. 6 inch wire leads. Weather proof sealed.

    The higher frequencies will give slightly more range than the lower ones. Lightning emissions have a slight peak frequency centered around 10 KHz.

    $ 30.00 each + s/h.

    Sales to USA and Canada only.
    Part number: 7SR-4.7 KHz. Best detection range at night.
    Part number: 7SR-6.5 KHz. Day and night. Increased detection range at night.
    Part number: 7SR-8.2 KHz. Day and night.
    Part number: 7SR-10.0 KHz. Day and night. Peak frequency for cloud-to-ground lightning radio static emissions.
    Part number: 7SR-12.8 KHz. Day and night.
    Part number: 7SR-40.0 KHz. Day and night. Increased detection range at night.

    Data Sheet pdf

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


    LF Lightning Detection Antenna. 350 KHz.

    These 7 inch long antennas can be used to detect lightning flashes up to 50 miles away. Severe thunderstorms emit continuous radio static at this frequency due to in-cloud and cloud-to-cloud lightning flashes. Series resonant. Factory pre-tuned to 350 KHz, tolerance +/- 5 KHz. 6 inch wire leads. Weather proof sealed.

    $ 30.00 each + s/h.

    Sales to USA and Canada only.
    Part number: 7SR-350 KHz.

    Data Sheet pdf


    AM / LW BAR CORE ANTENNA
    AM antenna rod core coil

    This AM / LW loopstick antenna is for tuning between 100 KHz - 1710 KHz.

    When used with our AM variable capacitor, above, this AM core will the full AM band and down to about 310 KHz. This tuning range is with the coil centered as in the photo.

    Size: 3.53 inches long by 0.31 inch diameter at widest dimension. 0.026 inch diameter at narrowest dimension (has two flat sides top and bottom so it won't roll away).

    Coil inductance value (centered on rod) is: 788 uH. Permeability value: @ 125 (designed primarily for AM broadcast band).

    The unit contains two coils. One coil (the green and red) are the smaller coil. The black and the white are the longer coil. The coils are isolated from eachother, but can be connected make one continuous coil having a tap. The above tuning results were tested only with the white and black wires used (the larger coil side).

    The red and green wires are isolated from larger section and can be used to couple an outdoor long-wire antenna.

    A very useful part!

    AM-LW BAR-1 is $ 6.95 + s/h.

    Sales to USA and Canada only.

    s/h extra.


    How to use the antennas and General Antenna Info

    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).

    U.S.A. only. No Foreign Orders.

    Sales to USA only.

    EXAMPLE USE:

    These directional antennas detect the magnetic field part of the VLF or LF radio wave. This field is strongest near ground level so do not mount the antennas high in the air. Simply 5 feet above ground will do the trick. The antenna will also work indoors in most cases and can even work underground, especially the VLF and lower frequency antennas.

    You can tune the antenna simply by placing a variable or permanent-value capacitor across the binding post connectors. Examples for min-max values for this capacitor are shown above on this page with the antenna models.

    ELF and ULF and SLF antennas can also be tuned with a fixed-value capacitor. The ELF antennas are generally wideband antennas, however.

  • HOW TO USE WITH A RADIO THAT DOES NOT HAVE ANTENNA JACKS:

    Most portable longwave radios have a built-in bar-core antenna that will very easily pick up the strong magnetic field from this antenna.

    Simply place the (top) of the portable longwave radio near the antenna, and tune capacitor until the signal gets louder and stronger. Results should be -very- dramatic.

    Rotate radio and ANTENNA for best reception.

  • HOW TO USE WITH A RADIO THAT HAS ANTENNA INPUT VALUE BETWEEN 50 ohms to 150 ohms:

    This keeps the antenna isolated to prevent noise pickup:

    Wrap 1 to 4 turns of wire around the center of the antenna's outer plastic case. Connect these wires (with some coaxial cable or other antenna cable) to the radio's antenna and ground terminals. Adjust tuning capacitor across antenna's binding posts for strongest signal. Add or subtract wire turns on antenna's outer case until signal strength does not increase further when re-peaked each time after adding or subtracting one turn at a time. The point where signal strength does not increase further is the correct match point for your radio.

  • HOW TO USE THE ANTENNAS HAVING 100,000 OHMS OUTPUT:

    These antennas are usually for use below 1000 Hz.

    Connect antenna directly to equipment's high Z input jack. Equipment should have JFET or FET input, or an input impedance of about 1 meg ohm. Most oscilloscopes and some test equipment have this type of input.

    A tuning capacitor can be placed directly across the binding posts if applicable to tune the antenna to desired frequency.


    NEED MORE GAIN? OR DON'T HAVE A HIGH IMPEDANCE INPUT?

    High impedance preamplifier for use with antennas having 100,000 ohms output impedance.

    You can greatly boost signal gain by using a pre-amplifier if your equipment does not already have a high impedance input. "CF" is a capacitor that controls frequency. Typical values are shown above on this page. Q1 is 2N3904 NPN transistor. R1 is 470 K-ohms. R2 is 1000 - ohms. R3 is 10 K-ohms. C1 is 47 pF. C2 is 0.001 uF.

    Supply voltage can be from 3 volts to 12 volts, depending on how much gain you want. Works well at 6 to 12 volts.

    Other amplifiers or IC chips or an FET may be more suitable than this sample single transistor example. But, if building this example circuit for the first time, do not substitute the 2N3904.

    See below on this page for link to an FET pre-amplifier you can build.


    Most test equipment already contains a built-in preamplifier. Just connect antenna directly to equipment input.


    LIST OF Do-It-Yourself VLF RADIO PROJECTS:

    VLF and Longwave Receiver for High Impedance "C" Antennas.
    07-08-2011. This direct input tuned receiver works with our Model "C" antennas above on this page, in the range of 10 KHz to 530 KHz.

    Lightning Detector project 11.
    07-16-2011. Uses our Lightning Detection Antenna part # D6T-3KC-BC.

    ELF Extremely Low Frequency Receiver. project 12.
    07-19-2011. For use with any of our high impedance ELF antennas.

    Longwave and VLF Receiver with Signal VU Meter.


    Build an AM radio!

    VLF Receiver with Signal Strength Meter.

    Wideband ULF - VLF FET Pre-amplifier.

    VLF / LF (Tunable) FET Pre-amplifier

    ELF Magnetic Field Detector.

    VLF Whistler Receiver.


    Some users in the AM and LONGWAVE bands who like to use long wire antennas (that sense the radio wave's electric field) can also use the antenna as a pre-selection tuned antenna.

    It is important to match your long wire antenna to the receiver to cut interference and maximize signal strength.

    To match a 50 ohm input in the AM and longwave bands only 1 to 4 turns centered on the outer case will be needed.

    For matching VLF down to 3 KHz it is possible to get a 50 ohm match by winding more than 10 turns around the center of the outer case. A 50 ohm match gives a very narrow bandwidth at VLF. Most VLF receivers have a high input impedance value which the antenna will directly match across the binding posts.

    MATCHING TIPS: You have a correct antenna match (usually 50 or 75 ohms) to your receiver's input when adding 1 more turn does not greatly improve the reception strength (less than 0.5 dB increase in added signal strength). Remove that extra turn for the correct match point. You can also slide the turns over the case to find strongest signal strength point.