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AM Broadcast Band Antenna
Data Sheet
Part # 11AM-530K-1710K-SP-BNC.

tuned directional antenna

This antenna covers the range of 530 KHz through 1710 KHz. For reception of AM broadcast band.

This antenna detects the magnetic field part of the radio signal. It is a directional antenna. Rotate it for best reception or to null out interference.

Features BNC female coaxial output jack for direct connection to your receiver's high impedance input or to use for connection to tuning capacitors.

TUNING DATA:

An 384 pF capacitor across antenna's BNC jack gives approximately 530 KHz.

An 10 pF capacitor across antenna's BNC jack gives approximately 1710 KHz.

You will need a variable tuning capacitor with this range. STORMWISE has a capacitor unit for $ 18.00 + s/h.

Tuning Circuits and General Info

EXAMPLE USE:

You can tune the antenna simply by placing a capacitor (CF) across the BNC jack. Example values for CF are shown above on this page.

MOST PORTABLE AM RADIOS HAVE A built-in bar-core antenna that will easily pick up the magnetic field from this antenna.

  • TO USE THE ANTENNA: Simply place the (top) of the AM radio near the antenna, and tune CF until the broadcast signal gets louder and stronger. Results should be very dramatic.

    Rotate AM radio and ANTENNA for best reception.

    If you want to (or still need to) make wire connections see below on this page.


    Direct connection to receiver through matching network to match antenna to a 50 ohm antenna input.

    CF is a capacitor that controls frequency. Typical values are shown above on this page. RS is a NON-INDUCTIVE carbon-film resistor. Typical value is 52 ohms. CC is a coupling capacitor. Typical value is 0.01 uF.

    Coaxial cable between Antenna and matching network should be kept short length (less than 2 feet) so not to add extra capacitance that will cause the antenna to tune lower than spec values indicated above for CF. Typical coaxial cables have 10 pF to 20 pF capacitance per foot.

    Cable between receiver and matching network can be any practical length.


    Typical use. Magnetic coupling to match a 50 ohm input.

    The antenna has a magnetic field generated at the receive frequency that can be coupled to your radio receiver. You can feed long lines of coaxial cable, with the tuned antenna located remotely. Cable length will not affect tuning range. CF is a capacitor that controls frequency. Typical values are shown above on this page. Coil wound on center of outer case couples signal out. Low Z. Wind until desired signal strength is received. Too many turns will begin reducing signal strength. Back off a few turns and this will generally be the perfect match point for your receiver. Make sure antenna remains peaked to center of test frequency.

    Number of coupling turns will usually be 1 or 2 turns of any type of wire wrapped around the center of the antenna. 1 turn centered on the antenna usually generates enough signal output for a 50 ohm load.


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

    But, if your equipment does not have a high impedance input, or requires more gain, this pre-amp will work. 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.


    ALL ANTENNAS CONTAIN A SUPPRESSOR TO PREVENT HIGH VOLTAGE SPARKING OR TRANSMIT DRIVE ACROSS THE OUTPUT TERMINALS. THESE ANTENNAS ARE -NOT- FOR PRODUCING HIGH VOLTAGES OR FOR TRANSMITTING. WITHOUT LIMITER HIGH VOLTAGE SPARKING WOULD DAMAGE ANTENNA IF TRANSMITTING ATTEMPTED.