HF High Power Impedance Transformers

Off Center Fed (OCF) antennas are very convenient as they will allow multiple bands of operation with a simple wire antenna which is fed off center. For example, the Palomar Engineers 4010 OCF is a very popular antenna and consists of an off center fed dipole with sides of 55 feet and 11 feet and it will work all bands from 40-6 meters.The End Fed OCF uses the same dimensions but the wire section is 55 feet as in the OCF and the coax outer braid is used for the “other” short side of the OCF dipole. We place a choke on the coax at the 12 foot distance from the matching unit and we essentially have an OCF antenna with its great frequency range, but with only a 55 foot wire length instead of the 66 feet required by the regular OCF. You feed the antenna from one end which may be more convenient for some installations. This antenna will work on 40-30-20-17-15-12-10 and 6 meters. Most bands are under 3:1 SWR and easily tuned by your transceiver’s internal antenna tuner or external tuner used with an amplifier. (see BULLET-4006 for specific details and SWR curves).

These antennas are MUCH BETTER PERFORMERS than End Fed Half Wave antennas because they work the WARC bands, DO NOT HAVE A DANGEROUS HIGH VOLTAGE at the antenna connection and are SHORTER to fit in smaller spaces yet provide more band coverage up to 6 meters!

The high power ferrite impedance transformer series (> 1:1), configured with outputs to act as a baluns (unbalanced coax in to balanced load output) or as ununs (unbalanced coax input to unbalanced load output) are designed for demanding radio transmitter stations that run over 1,000 watts PEP or run continuous modes like AM, digital, RTTY, FM, etc. at high power levels. Radio contest operators, commercial shortwave broadcast, and industrial and commercial stations use these transformers for for a variety of balanced and unbalanced antenna loads.  Baluns are typically used for balanced loads and antennas like dipoles, loops, log periodics, and direct feed yagi/beams.  Ununs are used  with verticals, end fed wires, horizontal dipoles, G5RV/ZS6BKW, Zepps, vertical wire beams, etc).  All products are in an enclosed NEMA water resistant box with SO-239 input connector and stainless steel side/top studs with wing nuts or side and top eyebolts.  The enclosure box has mounting “side feet” for attachment to a post or antenna boom using nylon ties.