Designed for use with end fed wire antennas and multiband verticals, this unun is small, compact and perfect for quick portable/emergency installations. This 4:1 Unun (200-50 ohms) will easily handle 300 watts and covers 1.5 - 54 MHz. Using this unun will allow transceivers with internal antenna tuners to work most if not all HF bands. A 28-31 foot wire will allow 40 thru 10 meter coverage and a 43-50 foot wire will provide access to 80 thru 10 meters. A good ground or counterpoise is also required.
This model also works well with any of the 19, 31 and 43 foot portable verticals and the wing nut model makes setup and breakdown quick and easy. If you have a 43 foot vertical, a long wire over 200 feet and/or want to run high power, consider the model 4132s or model 4134s which provides additional inductive reactance for enhanced performance on the lower bands.
Installation Notes and Recommended Wire Lengths
The enclosure for our low power units is small, lightweight and portable, but not intended for long term 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 is not covered under our warranty.
BNC & N connectors are available in "Accessories & Connectors" section of our website
|Core Material|| Custom mix low permeability ferrite by Fair Rite Products for maximum bandwidth.
Core is coated and sealed for long term durability.
|Winding Type|| Single core 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|| Bifilar winding of silver flashed 18 gauge Teflon insulated wire.
5000v breakdown voltage
|Power Rating|| 1.5 to 35 MHz - 300 watts, 35 to 54 MHz - 200 watts.
All ratings based on resonant load. High SWR will reduce power handling ability.
|Useable Frequency||1.5 to 54 MHz|
|Insertion Loss|| Less than 0.1db
|Connectors|| SO-239 connectors are silver plated with Teflon insulation.
Alternate connectors and Mounting Options are available in the Accessories section.
|Hardware||All Stainless Steel|
|Enclosure Type|| Polycarbonate (ABS) box with bottom plate that fits flush with the case
Plate is an exceptional fit that can be easily weatherproofed if desired.
|Dimensions|| Very compact 3x2x1.5 inch - Link to dimensional drawing
|Additional Info||Very high efficiency (98-99%).|