CUBE™ Vertical Antenna Feed Line Choke, 1.8-61 MHz, 1.5KW
| Quantity | Price per item | Discount |
| 10 items | $107.95 | 10% off |
Feed Line Chokes for Vertical Antenna with radials/counterpoise
Feed line chokes for verticals require a special arrangement to isolate the coax feed line from the radials and ground system. Schematically, a good feed line choke for verticals with radials should be built as follows:
Our CUV-1-1500 and CUV-1-5000 feed line chokes are all internally connected to isolate the coax feed line as shown above.
Th CUV-1-1500 unun is a common mode feed line choke for vertical antennas with radials that need to be isolated from the coaxial feed line to keep common mode current from using the coaxial braid as another radial. Very effective with high choking of 1K-5K from 1.8-61 MHz and also incorporates two side studs/wingnut terminals for radial or ground connection at the antenna while isolating the coax feed line braid from the radials via the internal common mode feed line choke. Top terminal with stud/wingnut for vertical connection enclosed in a 4″ x 4″ x 2″ box..
To reduce receiver common mode noise for long runs of coax to your antenna, use a MC-1-1500 or CU-1-1500 feed line choke at the station end of the coax.
SLIP-ON FERRITE BEADS
Baluns are used to connect balanced antennas to unbalanced transmission lines (Coaxial cable) and Ununs are used to connect unbalanced transmission lines to unbalanced transmission lines or unbalanced antennas (e.g. verticals). In the case of 1:1 baluns the input is usually an unbalanced coax cable and the output load is a two terminal balanced load like an antenna. Ununs are also called line isolators, feed line chokes, and 1:1 coaxial baluns (incorrectly). 1:1 Baluns and ununs stop common mode currents (flowing on the outside of the coax braid due to skin effect) when they are located at the antenna feedpoint. They can also be used as “line isolators/chokes” anywhere along the cable to suppress flow of induced RF (antenna near field radiation and neighborhood noise pickup) which helps suppress RFI into the radio receiver/transmitter. For best results, put one at the antenna feed point connection, and one at the radio room entrance, and for difficult common mode current cases, one every 1/4 wavelength along the antenna feed line. For low (below 3 MHz) frequencies, use two 5 bead baluns in series to double the choking impedance or order the 10 bead or 15 bead version for higher choking power.