Description
The DX Shop are distributors for Balun Designs
Heavy duty 5kW, 4:1 Unun designed for use with wire verticals, long wires and multiband monopole verticals. Utilizes stacked cores to deliver efficient broadband performance and high power rating across all HF frequencies. Works well with both internal transceiver and external antenna tuners.
This Unun is an excellent match for any of the 43 and 31-33 foot multiband verticals including the S9, ZeroFive, MFJ and DX Engineering vertical antennas allowing the use of full legal limit ++ power.
Although many customers report very good performance using just a single ground rod, the best performance will come from using at least 4+ ground radials or several elevated radials. In a temporary or emergency situation, a single counterpoise can be used when cut to approximately 1/4 wavelength of the lowest operating frequency.
Caution
Ununs are intended for use with unbalanced antennas such as verticals and long wires. They will not work with balanced designs such as dipoles or loops and use with a balanced antenna may cause erratic operation and/or damage to the unit.
Specifications
| Core Material | Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth. Cores are coated and sealed for long term durability. |
| Winding Type | Stacked cores with single bifilar wire pair wound as 4:1 unun. Downward impedance transformation by factor of 4. i.e. 200 ohms to 50 ohms. |
| Winding Material | Single bifilar winding of 14-gauge Heavy build polyamideimide Allex 240 Winding Wire. Windings are inserted into Teflon tubes increasing total breakdown to 10,000 volts. |
| Power Rating | 1 to 35 MHz – 5kW, 7kW intermittent. 35 to 54 MHz – 4kW. |
| Useable Frequency | 1 to 54 MHz |
| Insertion Loss | Less than 0.1db |
| Connectors | SO-239 connectors are silver plated with Teflon insulation. Studs and eyebolts are 1/4 inch. |
| Hardware | All Stainless Steel |
| Enclosure Type | NEMA rated 4x marine grade junction box for outdoor installations. Cover utilizes integral neoprene gasket for weatherproof integrity. |
| Dimensions | 4x4x2 inches for main body of unit |
| Additional Info | Very high efficiency. Will not heat up or saturate at like many of the “less expensive” designs. |