After many requests we have created a compact, special balun for single band loop (Sky loop or Delta loop) antennas with specific dimension that present a feedpoint of 70-75 ohms. The CB-1.5-1-1500/5000 is a CUBE(TM) enclosure containing a multi-core, broadband 1.5:1 impedance transformer (50 ohm coax input to 75 ohm balanced output) in series with a 1:1 current balun for extra common mode current choking to keep RF current off the outside of the coax braid and on the antenna where it belongs. The extra choking action also means that the coax feed line will not act as a radiator causing unnecessary RF interference (RFI). Rated for full 1500 watts PEP and 1500 watts CW (ICAS), 1KW Digital. 1.8Mhz – 61 MHz.
CB-1.5-1-1500EB is housed in a 4” x 4” x 2” waterproof housing with SO-239 input and stainless steel eye bolts on the side for ease of connection to your wire antenna (or top studs as desired). Top eye bolt acts as an antenna hoist. Also available with top studs for post or wall mounting (Model # CB-1.5-1-1500/5000TS). 5KW models are in a 4 " x 4" x 4" housing.
Loop antennas should be cut for 1005/F(MHz) in total length, where F (MHz) is the lowest frequency to be used. For 3.5MHz this equates to 288 foot perimeter (square, delta, multi-side ok). Vertiucal loops with pointy side up and longer bases and fed 1/4 wavelength down one side have a feedpoint impedance near 75 ohms for which this balun is well suited. A very good DX antenna!
For unbalanced 50 ohm input to unbalanced 75 ohm output use the CU-1.5-1500 or CU-1.5-5000.
Display Note: Product picture is 2:1 balun, 1:1 Unun but actual delivered product is CB/CU-1.5-1-1500/5000 as selected.
Generator RFI testimonial:
Bob Received your order in a timely fashion. Tried the generator kit on Sunday & it drops the noise from S9 to S5 and took out all the electrical noise. I may want some more toroids from you at some point for other interference problems I have here. Ken VE3KCY
Using an amplifier? Don’t forget our Linear Amplifier RFI Kits
Want to make up your own RFI kits for a particular operation? Here are links to some of typical RFI solutions used in portable operations:
If you use a computer for logging in your portable operations, RFI getting into computers will often lock up your computer and/or radio and a computer RFI suppression kits may be helpful
Make your expedition or portable operation a pleasant and fun outing and remember to take along your RFI kits so you have more time to operate rather then to troubleshoot intermittent or noisy receiver conditions.
Portable Antenna Kits
If you need an effective portable antenna which folds up for transport yet is easy to deploy at your operating site, consider the BULLET series of end fed wire antennas.
BULLET Antennas (click on link or picture for more info)
