Model 4115 - Dual Core 4:1 Current Balun 5kW 1 - 54 MHz

This is a balun originally designed by Guanella and subsequently improved by Dr. Jerry Sevick (W2FMI). By utilizing Thermaleze wire inserted in Teflon tubes, Dr. Sevick was able to substantially increase the breakdown voltage between both conductors and windings while maintaining the required 100 ohm characteristic impedance.

This design utilizes two separate cores wound as 100 ohm, 1:1 choke baluns which are cross connected to create a 4:1 (200 to 50 ohm) current balun with excellent isolation and high choking impedance. Consequently, this balun provides a high level of feedline isolation and is also a good choice if you have RFI problems or RF in your shack due to imbalanced ladder line. Please review the scans below to appreciate the excellent specs this balun offers.

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   All testing done with an AIM-4170c Network Analyzer and precision 200 ohm load

***CAUTION*** 

When used with a wire antenna, if one or both legs of your antenna will be installed over or close to (< 20 feet) your house, a large structure (garage, barn, etc) or near (< 30 feet) a metal roof/structure and you will be transmitting greater than 700 watts CCS,  DO NOT use this 4115 balun.  The interaction/coupling of the antenna with the structure and or metal will require high levels of common mode absorption by one ferrite core which will generate excessive heat in the core leading to a change in SWR and possible damage to the balun.  Instead use our new Hybrid model 4116 which is not effected by this caution and also incorporates a 1:1 choke balun.

Specifications

Installation Notes