This model is the popular Isolation/choke balun that is perfect for feedline isolation, noise reduction and RFI management. The model 1110b and 1110w are great for quickly deploying a center fed monoband dipole or monoband verticals.
By design, QRP baluns are constructed to be lightweight and portable and are not intended for longterm or permanent outdoor use. If used in a permanent outdoor installation, additional attention must be given to weatherproofing and strain relief. Damage caused by such use will not be covered under our lifetime warranty.
Be sure to look at the unique mounts available for the QRP line of baluns
This is a current balun and has the widest operating frequency range, lowest core stress and provides the best overall balance of any balun for given cost, size, and weight. This balun is the best type to balance currents on each side of a 1/2 wave dipole or the driven element of a yagi while providing the perfect transition from a balanced antenna to unbalanced coax feedline.
Installing this balun will not affect antenna matching unless the feedline is acting as part of the antenna. This is, of course, not a desirable situation and installing this balun will correct the problem if one exists with the antenna. In beam installations, using a 1:1 balun in series with the antenna’s feed system can substantially improve the antenna’s front-to-back and front-to-side ratios. It does this by providing the antenna's driven elements with balanced current at the feedpoint and by preventing the feedline from acting as part of the antenna.
It is a seldom appreciated fact that feedlines, which are not adequately decoupled, can act as efficient vertical antennas degrading an otherwise excellent radiation pattern. The addition of a 1:1 balun can significantly reduce feedline radiation and dramatically decrease RFI and TVI. Beam antennas especially benefit from improved balanced drive and superior feedline isolation, but even simple dipoles benefit from properly selected and installed 1:1 current baluns. Receiver noise may also be reduced by eliminating signal pickup by the coax shield.
- Utilizes specifications of Jerry Sevick, W2FMI, the authority on baluns. This is his Guanella current balun design which he modified to provide higher efficiency.
- By utilizing a custom toroid mix with low permeability, the bandwidth of his design has been increased. Toroid is coated with epoxy paint for added durability.
- This Isolation balun has significantly higher common-mode impedance and larger effective core area than other similar designs. It is much more effective than types with ferrite beads, ferrite bars or wound air-core coax.
- Windings are mil spec teflon insulated coax.
- Typical insertion loss is less than 0.1 dB
- Power handling upto 300 watts continuous
- All hardware is stainless steel. Very high efficiency. Will not heat up or saturate like many of the typical cheap current baluns.
- Alternate connectors are available in the Accessories section.
- Balun is built installed in a very compact 3 X 2 X 1.5 inch polycarbonate enclosure with a bottom plate that is an excellent fit. Weatherproofing can be easily attained.
This balun will handle continuous power of 300 watts max and tolerate high SWR for extended periods.
It will not heat up under extended duty cycles or stressing load conditions.