Broad Band Terminated Dipoles (BBTD, T2FD)

Broad Band Terminated Dipoles (BBTD), Tilted Terminated Fold Dipoles (T2FD) and Balanced Termination Folded Dipole BTFD) antennas can be designed to cover a large range of frequencies between 1.8 30 MHz.  Longer length antennas generally provide better low frequency efficiency but take up a larger footprint of land.   One BBTD that has worked well at the AK6R antenna farm is shown below.  Many other designs are available and can be found at www.HFLINK.COM as well as other internet sites.  Your mileage may vary using this antenna, but as a general coverage antenna for ham and shortwave broadcast, the simplicity can’t be beat even though an individual dipole on a specific band may out perform this broad band dipole.  Palomar Engineers has all the parts you need to build this antenna, so why not give it a try?

BBTD at AK6R 1024x726 - Broad Band Terminated Dipoles (BBTD, T2FD)

 

Depending on the source of the antenna design, different value baluns are specified.  Our Bullet(TM) baluns in ratios of 9:1, 12:1 and 16:1 are excellent for this type of antenna as they are broadband from 1.8-61 MHz and will take up to 500 watts PEP.

MAXI-CHOKER Coax Line Isolator/Balun, 1-61 MHz, 1.5/3KW, SO-239 In/Stud Output, FLAGPOLE OCF, G5RV, ZS6BKW, BN4000 Replacement, Ladder Line-Coax interface

SKU MC-1-1500LL
$89.95
PEP Power
1
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MAXI-CHOKER Coax Line Isolator/Balun, 1-61 MHz, 1.5/3KW, SO-239 In/Stud Output, FLAGPOLE OCF, G5RV, ZS6BKW, BN4000 Replacement, Ladder Line-Coax interface
Product Details
Brand: Palomar Engineers
MPN: MC-1-1500LL or MC-1-3000LL
Country/Region of Manufacture: United States
Effective Frequency Range (MHz): 1-161
PEP Power Rating (watts): 1500 or 3000 to 61 MHz, 500 watts to 161 Mhz
Choking Impedance Range (ohms): 500-6000 (1-61 Mhz)
Common Mode Attenuation (db): 20-35db
Estimated Insertion Loss (db): .25 db
Input Connector Type: SO-239 female
Output Connector Connector Type: Top Studs
Ground Connector (Y/N): optional
Enclosure Size (LxWxH inches): 8 or 12" long, 2.5 in diameter

MAXI-CHOKER Features:

- Uses proprietary Multi-Mix(TM) technology for maximum choking (up to 5K ohm) and maximum bandwidth

- 1.5 KW or 3 KW PEP Option, 50 ohm SO-239 connectors In dual screw terminal output for ladder line or dipole driven element, etc. effective 1-61 MHz

- Up to -48dB common mode suppression solves tough RFI issues

- Works for all coax fed antennas from 1.8-61 MHz (160-6 meters) - excellent for multi-band beams, verticals, dipoles, off center fed antennas, tri-band beams.

- 2-5 times more choking resistance, wider bandwidth and higher power then competing filters

- great replacement choke for G5RV/ZS6BKW antennas or as a 1:1 ladder line to coax interface for Flagpole OCF type antennas with high common mode choking to isolate the coax braid from becoming part of the antenna.

- Available with ground lug/internal static bleeder option

- Excellent replacement for Hygain BN4000D balun used on beam antennas


MAXI-CHOKER feed line chokes are used to suppress common mode current carried on the outside of the coax braid which is often responsible for receiver noise and RFI in the receiver/transmitter. These chokes are very useful for suppressing RFI common mode current at the antenna feed point or at a ladder line to coax junction, like a G5RV antenna.

Note: Color may be white or black depending on on inventory at time of order. Also available with SO-239 in/Out (MC-1-1500 or MC-1-3000) or with static bleeder/ground (MC-1-1500GB or MC-1-3000GB).





Likewise Termination Resistor values vary from 500-1250 ohms and we have a good selection shown HERE: