1500 Watt PEP rated 4:1 Current Balun + internal 1:1 Current Balun in one enclosure
After many requests we have created a compact, special balun for OCF and loop (Skyloop or Delta loop) antennas. The CB-4-1500OCF is a CUBE enclosure containing a multi-core, broadband 4:1 impedance transformer in series with a 1:1 current balun for extra common mode current choking to keep RF current off the outside of the coax braid and on the antenna where it belongs. The extra choking action also means that the coax feed line will not act as a radiator causing unnecessary RF interference (RFI). Rated for full 1500 watts PEP and 450 watts CW/FT8/RTTY (ICAS). 1.8Mhz – 61 MHz.
The CB-4-5000OCF (5KW PEP) have a frequency range of 1.8-31 MHz and does not cover 6 meters.
CB-4-1500OCF is housed in a 4” x 4” x 2” waterproof housing with SO-239 input and stainless steel eye bolts on the side for ease of connection to your wire antenna. Top eye bolt acts as an antenna hoist. Use this balun combination when you DO NOT have a vertical radiator.
5KW are in 6" x 6" x 4" enclosure. 1.5KW is 3 pounds, 5KW is 5 pounds. Note the 5KW models are made to order and shipment time is approximately 7-10 days after order date.
For a 135 foot 80 meter OCF, we recommend a 29.5%/79.5% offset for best all band results. If you use 66%/34% offset, do not use on 15 meters as the impedance mismatch may damage the balun under high power operations
We specify impedance ratios as an output to input ratio where the output (or load) is given first and the input is given second (e.g. 100:50 (2:1) would mean a 100 ohm output and a 50 ohm input; a 25:50 (1:2) would mean a 25 ohm load and a 50 ohm input). Most all products use a 50 ohm input unless otherwise specified.
We have products that are available as kits for the do-it-yourself (DIY) person or fully assembled and tested units for the “Plug & Play” crowd.
Our impedance transformers are available using two different topologies: Binocular cores or toroid cores with multiple turns for increased effectiveness and wide band frequency transformations. We utilize single and multiple core transformers using high order windings when needed to extend product performance.
We rate the power ratings as watts PEP (Peak Envelop Power) with standard duty cycles for various modes. To determine the PEP rating required for your needs, see: Choke & Transformer Power Ratings
This website page serves as a link page to the frequency ranges of our impedance transformers configured as either baluns or ununs. You can click on a picture to go to the specific page about the products described in the picture.