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.
BUY THIS KIT NOW TO SOLVE YOUR RFI/EMI NEEDS! WORKS WITH MANY BRANDS OF HAM/COMMERCIAL HF RADIOS WITH DUAL ANTENNAS OUTPUTS AND MULTIPLE I/O CONNECTIONS INCLUDING ALL SWAN TRANSCEIVERS (12X, 240, 250, 350, 400, 500, 700)
Kit Includes noise reduction ring filters for coax cable and AC power line, DC power (from 117XC or equivalent power supply), and 1 snap on filters for T/R relay cable covering RFI range of 1-300 MHz. Quick installation - immediate RFI/noise reduction. No radio mods required.
This kit will help reduce or eliminate:
1. “Hot mic” RFI caused by poor grounding of antennas or common mode currents from linear amps feeding unbalanced (coax fed) antennas without baluns/line isolators.
2. RFI to neighbor’s electronic devices including audio/video systems, computers, telephones, garage door openers, etc.
3. RFI to your other radios, audio/video systems, computers, telephones, etc.
A side benefit is a reduction in noise floor in your receiver depending on the amount of noise being introduced by common mode currents (which are blocked/reduced by the chokes in this kit).
These chokes use a special mix of ferrite core material that is effective in suppressing radio frequency interference from transmitters and high noise floor on receivers.
The split beads beads are easy to use, don’t require modification of the protected equipment and work in almost all cases, even when plug-in filters fail.
Use of the chokes often helps cure SWR problems between transceiver and a linear amp and between transceiver and antenna tuner or direct to antenna. The DC power line choke helps keep common mode current out of the power line which could cause interference to other devices connected to the same power line if not suppressed.
For additional RFI suppression, use a feed line choke (MC-1-3000) at the antenna feed point to suppress common current on the coax feed line and a coax noise filter (like our CMNF-500-50) at the radio end of the coax to further reduce common mode noise picked up by the coax cable braid.If you use a linear amplifier use a Palomar Engineers amplifier RFI kit for additional RFI interference suppression.
Likewise Termination Resistor values vary from 500-1250 ohms and we have a good selection shown HERE: