About the Buckmaster OCF Dipole Antennas
Buckmaster OCF Dipole Antennas work multiple bands and are made from the best quality materials. They have no external connectors and a permanently sealed white PVC weatherproof center enclosure containing the potted autotransformer acting as 6:1 voltage balun. Designed to give you years of trouble-free service, they are shipped ready to go with no trimming or assembly required and are available with 100, 300, or 3,000 Watt baluns and are offered in 4, 7, or 8 band lengths.
About power ratings: To work 4, 7, or 8 different bands on one length of wire we use a custom 6:1 balun. The 6:1 balun does a great job of matching but is subject to heating up with sustained usage at higher SWRs. So, it is important to buy an antenna with a balun that is rated at a higher power than what you will actually transmit. As a general rule of thumb:
100 Watt baluns support 100 Watts with 1:1 SWR, 50 Watts with 2:1 SWR, 33 Watts with 3:1 SWR, and so on. So they are for QRP work, not standard 100W transceivers.
300 Watt baluns support 300 Watts with 1:1 SWR, 150 Watts with 2:1 SWR, and 100 Watts at 3:1 SWR. This is why our 300 Watt models are a good match for 100W transceivers on the supported bands.
3,000 Watt baluns support a theoretical 3,000 Watts with 1:1 SWR, 1,500 Watts with 2:1 SWR, and 1,000 Watts at 3:1 SWR. 3,000 Watt models are needed if you run over 100 Watts, but the SWR numbers can also be better than 300W models in some cases, so you will be heard better. See our measured SWR numbers in the 4-Band, 7-Band, and 8-Band descriptions below.
Buckmaster OCF Dipole Antennas are a great simple way to get on the air and work multiple bands! They are shipped ready to go, all you have to do is screw in your coax and raise the antenna in the air. We have had many satisfied customers since 2004!
What You Need
An installation environment clear of long metal objects. THIS CAN BE IMPORTANT FOR ANTENNA PERFORMANCE. Long metal objects include metal poles, buildings, other antennas, towers, house wiring, fences, or gutters. Metal objects can be resonant on a band the antenna supports and interfere with RF coming to/from the antenna. Multi-band antennas work on many frequencies so there is greater chance that nearby metal may be resonant one or more of the bands. If you must install the OCF near metal objects, a minimum 10 feet separation is suggested. We do not recommend hanging the Buckmaster OCF Antennas from a metal tower unless you have a least a 10' standoff and/or hang the balun enclosure down from a 10'+ piece of rope and use the legs of the antenna to pull the balun enclosure away from the antenna. Having the Buckmaster OCF close to a metal mast or tower very often results in poor SWR on one or more bands! However, despite the above warning, metal near an antenna is not guaranteed to cause problems. It depends on whather that metal is resonant on a band the antenna supports. Usually the only way to know is to try, so it's best to have a backup install plan.Something non-metal to hang the center from, such as a tree branch, non-metallic pole, or a "messenger line", a rope stretched tight between two supports such as trees. Due to the weight of the balun, you must hang the antenna from the stainless steel eyebolt on the balun, you shouldn't hang the antenna from the ends alone. Tree branches must be trimmed so they do not contact the wire; the wire is tough and flexible but tree branches will gradually rub the insulation off and allow water inside, which will cause SWR to rise.Enough ground space for the antenna. Our antennas are designed and tested to operate in a straight line as viewed from above. Not having the antenna in a straight line will have negative performance impacts. A 4-Band OCF is 68 feet long, 7-Band is 135 feet long, and 8-band is 270 feet long. For small lots: with the antenna legs sloping down at the minimum 120 degree angle the 4-Band antennas need at least 60 feet of ground space from end-to-end, 7-Band antennas need at least 120 feet of ground space, and 8-Band antennas need 239 feet of ground space. If you don't have enough ground space, you will either have to try a different type of antenna or accept lower performance from bending the legs.Good quality 50 Ohm coaxial cable with appropriate power rating. Good coax such as: RG58, RG8X, RG8, RG213, Belden 9913F7, Davis RF Bury-Flex, or LMR-400. A coax with a dense (or double) braid is worth the money. Don't lose that weak signal in the coax!