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.
1/2″/12.7mm max Cable Size Chokes
Model SLO-1/2 family of chokes are for use with ½” coax cable like RG-8, RG-213, 9913, LMR-400 and similar cables up to ½” diameter – works on all cable impedances (50, 62, 75, 90 ohms etc). 80-6 meters.Choose SLO-1/2 (5 beads) or for extended choking, choose SLO-1/2E (10 beads) or for super extended choking choose SLO-1/2SE (15 beads).
Each additional 5 beads is approximately 6 dB of common mode rejection (also 1 “S” unit of noise reduction).
Select chokes with minimum of 500 ohms at your frequency of interest for best results or upgrade to our CUBE(TM), or MC-1-3000 Maxi-Choker(TM) chokes up to 10,000 ohms choking.
Select 5 bead version for 80-2 meters use; 10 bead version for 160-6 meter use, 15 and 20 bead version for even higher choking power on 160-20 meter frequencies. Power rating is same as coax cable used power rating.
Snap On and Slip on Feed line chokes available in sizes to fix cables with outside diameters of 1/4", 3/8", 1/2", 3/4", 1" - check website for other size options.
The 5 bead, 1/2" model was previously part # BA-8
Testimonial:
KI7AY
Wanted to let you know that I was having a problem with RFI on 40m, but immediately after installing your Slip On Coax Feed Line Choke -1/2"/12.7mm cable, 1.8-300 MHz on a new RG-213 jumper between the IC-9100 and tuner, IT WENT COMPLETELY AWAY!
Likewise Termination Resistor values vary from 500-1250 ohms and we have a good selection shown HERE: