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?
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.
The CB-1-5000AT Antenna Tuner Balun is a 50 ohm to 50 ohm, triple core feed line choke designed to provide high choking impedance between a balanced ladder line feed line (zepp, G5RV/ZS6BKW, extended double zepp, etc.) and short 50 ohm coax feed line (to antenna tuner) at a power of 5000 watts PEP from 1.8 to 61 MHz. The CB-1-5000AT is configured as a Guanilla transmission line transformer with balanced outputs (current balun configuration). It is best used when ladder line impedance seen at the end of the ladder line to balun connection is close to 50-150 ohms. Enclosure box is 4″ x 4″ x 2″. Typical choking impedance range is 1K-10K ohms from 1-31 MHz.
Typical ZS6BKW multi-band antenna with CB-1-1500 or CB-1-5000
Likewise Termination Resistor values vary from 500-1250 ohms and we have a good selection shown HERE: