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.
1500 Watt 4:1/6:1/9:1 CUBE™ Balun – Model CB-4-9-1500
Model CB-4-9-1500 is a 4:1 and a 9:1 balanced output (balun) housed in a Nema enclosure box (4″ x 4″ x 2″) with a top eyebolt halyard hoist, two side studs for 4:1 and two additional side studs for 9:1 outputs, each capable of input power levels up to 1.5 KW PEP when used with a matched load. The 4:1 ratio takes 50 ohms input and matches to 200 ohms output and the 9:1 ratio takes 50 ohm input and matches to 450 ohms output between 1-61 MHz under 2:1 SWR under matched load conditions.
Now you don’t need to buy two separate baluns or guess which balun to use - you get the 4:1 and the the 9:1 in a single package! – just buy the CB-4-9-1500 and pick the output ratio that best matches your antenna tuner! (Note: you can only use 1 set of outputs at a time)
Application note: If you use 1 of the 4:1 and 1 of the 9:1 terminals on opposite sides, then the output wlll be 300 ohms or a 6:1 balun!
Likewise Termination Resistor values vary from 500-1250 ohms and we have a good selection shown HERE: