Purpose. Model BA-9-1000 is a 9:1 balun/unun kit (assembly required from parts supplied) used to translate a 50 ohm input up to 450 ohms at RF power levels up to 1000 watts when used with a matched load. It provides conversion from unbalanced coax to balanced ladder line/antenna feed point and gives a 9:1 impedance step-up to reduce SWR on the coax. Place at the junction of the balanced line and the coax to convert from balanced line to unbalanced coax.It can also be wired as an UNUN with unbalanced coax input to unbalanced output such as an end fed antenna.
KIT Contents. The kit consists of a F240-61 ferrite toroidal core, three colors of insulated wire, a SO-239 UHF connector with stainless steel hardware, and an instruction manual.
Assembly time: About 1 hour
Radio Club idea:
Buy 10 for a club do it yourself construction project - you can learn something and also build an end fed antenna (just add wire).
16:1 Ununs are useful between coax and long wires with a load impedance near 800 ohms like a beverage antenna. Shortwave listener antennas also can benefit with the 16:1 unun and it may provide a better match than 9:1 ununs – this means quieter noise levels and stronger signals so you can hear distance stations easier.