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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: 0.3 Hz - 30 Hz.
  • ELF Antennas for detecting earthquakes, ground vibrations, and infrasonic sound waves.
  • Antennas for lightning detection.
  • SCROLL DOWN to see different antenna types for individual radio frequency bands below on this page.
    RADIO ANTENNAS

    Antennas for reception in the frequency range of 0.1 Hz to 5 MHz


    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 370 pF. @ 370 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.


    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. @ 370 pF tunes to 60 KHz. Great for series resonant use in small receivers.

    Weather proof sealed. 6 inch wire leads.

    $ 30.00 + s/h.


    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. @ 370 pF 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.


    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. @ 370 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.


    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. @ 370 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.


    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.


    Marine Band Shortwave Antenna

    ANTM5. This 6.5 inch long antenna can be tuned from 2.0 MHz to 3.0 MHz with an external capacitor value of 10 pF to 384 pF. @ 370 pF tunes to 2 MHz. Great for series resonant use in small transmitters or receivers. 1 watt max.

    Weather proof sealed. 6 inch wire leads.

    $ 30.00 + s/h.


    HAM Shortwave Antenna

    ANTM6. This 6.5 inch long antenna can be tuned from 3.5 MHz to 4.0 MHz with an external capacitor value of 10 pF to 384 pF. @ 370 pF tunes to 3.5 MHz. Great for series resonant use in small transmitters or receivers. 1 watt max.

    Weather proof sealed. 6 inch wire leads.

    $ 30.00 + s/h.


    WWV 2.5 MHz Shortwave Antenna

    ANTM7. This 6.5 inch long antenna can be tuned from 2.4 MHz to 3.0 MHz with an external capacitor value of 100 pF to 384 pF. @ 370 pF tunes to 2.5 MHz. Great for series resonant use in WWV 2.5 MHz receivers.

    Weather proof sealed. 6 inch wire leads.

    $ 30.00 + s/h.


    WWV 5 MHz Shortwave Antenna

    ANTM8. This 6.5 inch long antenna can be tuned from 4.9 MHz to 5.5 MHz with an external capacitor value of 100 pF to 384 pF. @ 370 pF tunes to 5 MHz. Great for series resonant use in WWV 5 MHz receivers.

    Weather proof sealed. 6 inch wire leads.

    $ 30.00 + s/h.


    RFID Antenna 134.2 KHz.

    These 7 inch long antennas are factory pre-tuned. Series resonant. 6 inch wire leads. Weather proof sealed. Great for low power transmitters (1 watt or less), and single frequency receivers.

    $ 30.00 each + s/h.
    Part number: 7SR-134.2 KHz.


    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.
    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.
    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


    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. 6 inch wire leads. Weather proof sealed.

    $ 30.00 each + s/h.
    Part number: 7SR-350 KHz.

    Data Sheet pdf


    LOWFER Antennas.
    160 KHz - 190 KHz.

    These 7 inch long antennas can be used in the part 15 low frequency band of 160 KHz to 190 KHz for reception.

    Series resonant.

    $ 30.00 each + s/h.
    Part number: 7SR-160 KHz.
    Part number: 7SR-161 KHz.
    Part number: 7SR-165 KHz.
    Part number: 7SR-170 KHz.
    Part number: 7SR-175 KHz.
    Part number: 7SR-180 KHz.
    Part number: 7SR-185 KHz.
    Part number: 7SR-189 KHz.
    Part number: 7SR-190 KHz.


    Seismograph ELF Antenna.
    ANTENNA DETECTS EARTHQUAKES

    For use in

  • seismographs,
  • infrasound sensors,
  • magnetic sensors,
  • ELF - ULF reception,
  • ELF - ULF tuners,
  • pipeline inspection gauge sensors, etc.

    This antenna operates in the range of 0.01 Hz to 1 KHz, and is designed for high sensitivity in this range when used for sensing tiny physical motions of a nearby magnet. Typical applications are seismographs and infrasonic microphones and remote motion sensing of moving magnetic or magnetized parts (can detect rotational speeds up to 1000 revolutions per second).

    This antenna is very sensitive and allows a simple seismograph to be built for earthquake detection. This antenna will detect large earthquakes over 1000 miles away. Perfect for your use in your DIY seismograph. We like this antenna the best because it is small and very sensitive.

    You can also build an infrasonic microphone for detecting infrasonic sound waves in the range of 0.01 Hz to 20 Hz.

    These 6.5 inch long by 1 inch diameter antennas are for use in seismographs. You can build a seismograph to detect earthquakes. Its easy: See this link: Bucket Seismograph 3.

    You can also build an infrasonic microphone to detect infrasound waves in the range of 0.01 Hz to 20 Hz. See this link: Bucket Infrasonic Microphone 1.

    Weather-proof.

    Part number: 8SR-1H-1K. $ 55.00 each + s/h.
    Data Sheet

    This recording made in Texas shows that the antenna easily detected the Magnitude 7.9 earthquake that was 24 km SE of Little Sitkin Island, Alaska on June 23, 2014 at time of 20:53:09 UTC. Earthquake Depth: 107.5 km.

    View more earthquakes recorded with the antennas.


    Extremely Low Frequency Antenna
    0.1 Hz - 100 Hz

    For use in

  • seismographs,
  • magnetic sensors,
  • ELF reception,
  • ELF tuners,
  • 45 Hz - 75 Hz power line detection,
  • pipeline inspection gauge sensors,
  • infrasonic microphones.

    These 10 inch long by 1.25 inch diameter ELF antennas are for use in seismographs and also for detecting movement of geomagnetic fields. You can build a seismograph to detect earthquakes. Its easy: See Bucket Seismograph 3.

    This ELF antenna is very sensitive and will detect large earthquakes over 1000 miles away, its the perfect sensor element for your use in your DIY seismograph.

    The antenna has a response of 0.1 Hz to 100 Hz and is tunable (with your single external capacitor) from 1 Hz to 100 Hz, see tuning data sheets below.

    The antenna is sensitive enough to detect motion of itself moving through the earth's magnetic field, this produces a DC voltage (up to 30 millivolts) across the terminal wires.

    Part number: 10SR-0.1H-100H. $ 88.00 each + s/h.
    Tuning Data Sheets.

    To detect cars and trucks by magnetic fields, place the 10SR antenna up to 10 feet away from a road. The 24SR (below) gives increased range.


    Extremely Low Frequency Antenna
    0.05 Hz - 50 Hz
    Magnetometer Antenna

    For use in

  • seismographs,
  • magnetic motion sensors,
  • ELF reception,
  • ELF tuners,
  • pipeline inspection gauge sensors,
  • geologic research,
  • geomagnetic storm detection.

    These 24 inch long by 1.25 inch diameter ELF antennas are for detecting movement of geomagnetic fields. They are also useful in seismographs, ELF reception, ELF tuners, and magnetic motion sensors.

    The antenna has a response of 0.05 Hz to 50 Hz and is tunable (with your single external capacitor), see tuning data sheets below.

    The antenna is sensitive enough to detect motion of itself moving through the earth's magnetic field, this produces a DC voltage (up to 0.1 volt) across the terminal wires.

    The antenna will detect the actual shaking motion of itself through earth's magnetic field when a local earthquake occurs, you can make a seismograph with no moving parts to capure the actual earthquake waveform.

    To detect local earthquakes securely mount this antenna to a concrete block directly on the ground, or to two sturdy wood posts about 1 foot above ground outdoors. Make sure the antenna can not vibrate from the wind, touch, etc. When the ground shakes you get a record of the actual earthquake waveform on your seismograph, as the antenna moves around in Earth's natural magnetic field (no other magnet source needed).

    To detect geomagnetic storms, mount this antenna outdoors away from motor traffic. Point the ends so they are aligned with the magnetic North and South of a compass. You can also align with East - West to try something different. You can also point one end of the antenna down toward the ground. The antennas have a directional 'figure 8' pickup pattern.

    Use 3 antennas to get an X, Y, Z axis record of magnetic and earthquake events.

    Part number: 24SR-0.05H-50H. $ 200.00 each + s/h.
    Tuning Data Sheets.

    Comparison of what is detected by a seismograph (ground vibrations) and what is detected by the 24SR magnetometer antenna (magnetic field changes, movement through earth's magnetic field). Large trucks made of iron can be highly magnetized and detected at a distance of 100 feet. If the antenna were placed nearer to the road (10 feet) then cars will be detected also.


    Other specialty Antennas below

    WEATHER-PROOF ANTENNA CASE
    with suspension hook

    The following part numbered ELF antennas

  • 8SR-1H-1K,
  • 10SR-0.1H-100H,
  • 24SR-0.05H-30H.

    are available with this protective weather-proof case with an eye-bolt loop for suspension. Suspend the antenna over a magnet to make a seismograph, or suspend the antenna down a borehole for research.

    Binding post connections.

    Antenna models listed above can be permanently factory mounted in these weather-proof sealed cases with eye-bolt suspension loop.

    The case is 2.75 inches diameter.

    The case will be about 10 inches long for the 8SR-1H-1K, about 12 inches for the 10SR-0.1H-100H, and 26 inches for the 24SR-0.05H-30H.

    Add $ 60.00 to the price of antenna and add 'EB' to the end of the antenna part number to order your antenna permanently factory installed into a weather-proof case.



    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.

    s/h extra.

    Sales to U.S.A. only.


    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.