Description of Balanced to Unbalanced Transformers , Prices and Shopping Cart

Description of Unbalanced to Unbalanced Transformers, Prices and Shopping Cart

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High Power UNUNs ( Unbalanced to Unbalanced Transformers )
Designs based on Jerry Sevick, W2FMI.

Fully encapsulated and water-proof versions are now available.

  • Only CWS ByteMark manufactures these Ununs based on Jerry Sevick's (W2FMI) designs.
  • Broadest Bandwidth (1 MHz up to 50 MHz)
  • Lowest Energy Loss ( < 0.2 dB)
  • Aluminum Casing with SO 239 Connectors, on both Inputs and Outputs. N2 connectors availabe on request.
  • Dimension: 4 x 2 x 2.8 (same for all models)
  • Typical Applications: Matching unbalanced 50 ohm coaxial cable to :
    • Ground Fed Antennas - Shortened Verticals, Vertical beams, Slopers and Inverted L's. Use 4:1HCU50, 1.78:1HDU50, etc.
    • Shunt Fed Towers performing as Verticals. Use 1.56:1HDU50
    • 75 ohms coaxial cable (unbalanced). Use 1.5:1HU75
    • Junction of two parallel 50 ohms coaxial cables (resultant impedance of 25 ohms. Use 2:1HDU50
    • Output of a Transceiver when a large VSWR exists on the cable. Depending on coaxial cable's termination at the other end, the cable's impedance at the Transceiver end could be different from the cable's normal impedance.
    • Beverage Antennas. Use BEV-U50 Matching 50W to 800W, 612W or 450W

    The unun should find some important applications. Until recently, they have been literally impossible to obtain. But now they can be designed to match 50-ohm cable to loads as small as 3.125 ohms and as high as 800 ohms (both unbalanced loads). They can come in low-power and high-power versions as well as multimatch designs. An important application for ununs is to match 50-ohm cable to the input impedance of ground-fed antennas such as verticals, slopers, inverted L's and towers performing as verticals. Since ground losses play a large role with these systems, a knowledge of the input impedance of the antenna as well as the ground loss is important in determining the optimum impedance ratio. The low-power multimatch unun should find use in the operating room when an unfavorable impedance is presented to the transceiver. Also, a high impedance, multimatch unun can be easily designed to match 50-ohm cable to the input impedance of Beverage antennas. It should also be pointed out that ununs can be employed in series with baluns to provide a host of wideband baluns and ununs with ratios which have been previously unattainable.

  • Please use the VeriSign Secure on-line shopping cart below to order these UNUNs. Almost all models are available from stock for immediate shipment to you.

  • Download Specifications and Data sheets in .PDF
    Materials, Q curves, Inductance Charts, etc
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