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.
Purpose. Model BA-9-1000 is a 9:1 balun/unun kit (assembly required from parts supplied) used to translate a 50 ohm input up to 450 ohms at RF power levels up to 1000 watts when used with a matched load. It provides conversion from unbalanced coax to balanced ladder line/antenna feed point and gives a 9:1 impedance step-up to reduce SWR on the coax. Place at the junction of the balanced line and the coax to convert from balanced line to unbalanced coax.It can also be wired as an UNUN with unbalanced coax input to unbalanced output such as an end fed antenna.
KIT Contents. The kit consists of a F240-61 ferrite toroidal core, three colors of insulated wire, a SO-239 UHF connector with stainless steel hardware, and an instruction manual.
Assembly time: About 1 hour
Radio Club idea:
Buy 10 for a club do it yourself construction project - you can learn something and also build an end fed antenna (just add wire).
Likewise Termination Resistor values vary from 500-1250 ohms and we have a good selection shown HERE: