Coax Inline Common Mode Choke Unun - 500 Watts 25-300 MHz- 10, 11, 6, 4, 2 Meters

Name: Coax Inline Common Mode Choke Unun - 500 Watts 25-300 MHz- 10, 11, 6, 4, 2 Meters
Brand: Palomar Engineers
SKU: FC-8X-3-31
Price: 27.95 USD
Availability: InStock

Store/Antenna Products/Coax Feed Line Common Mode Chokes/Common Mode Chokes, Line Isolators

SKU FC-8X-3-31

$27.95

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$39.95 Save 30%

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Output Connector

PL-259

Solder Lugs

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100 items	$17.95	36% off

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Coax Inline Common Mode Choke Unun - 500 Watts 25-300 MHz- 10, 11, 6, 4, 2 Meters

Store/Antenna Products/Coax Feed Line Common Mode Chokes/Common Mode Chokes, Line Isolators

Product Details

Brand: Palomar Engineers

MPN: FC-8X-3-31

Effective Frequency Range (MHz): 25-300 MHz (3 bead)

PEP Power Rating (watts): same as coax cable rating

Estimated Insertion Loss (db): .025

Input Connector Type: none

Output Connector Connector Type: none

Ground Connector (Y/N): none

Enclosure Size (LxWxH inches): none

ASSEMBLED COAX FEED LINE CHOKES

Many customers have requested an assembled sleeve unun or balun 1/4" size cable and we have one all completed with shrink tubing and PL-259 end connectors or open ended on one end for a balanced connection such as a beam, dipole, etc.

All you need to add are 2 barrel connectors (Part # DFBC-1) to insert into your coax cable. For best results add one feed line choke at the antenna to keep the RF on the antenna and another feed line choke at the station entrance to reduce the common mode noise picked up by the antenna braid and fed into the station. Rated 500 watts from 25-300 MHz into 1:1 SWR load.

Common Mode Rejection Ratio up to 20 dB (over 3 "S" units) - see graph for specifics..

Available with PL-259 output or solder lug output (for attachment to a balanced output such as a yagi antenna for dipole fed antenna

When considering solutions for AM broadcast (550 Khz – 1.8 Mhz) you should consider Mix 77 ferrites available in a variety of shapes and sizes. Choose a size to give the maximum number of turns of the affected wire or cable.

AM broadcast transmits on a low frequency with large antennas. Consequently it takes a large antenna to receive the signals. Typical “antennas” are AC house wiring, phone lines, long satellite or cable TV cables, DSL/CAT5 lines running between rooms, etc. The device wires that connect to these “antennas” need to be choked with as many turns through the ferrite as possible. Some installation examples are shown below on this page.

For AC/ DC power cords and coax cables the F240-77 (2.4″ OD, 1.4″ ID) “Donut” toroid is the most popular. Also available are smaller toroid donuts and Mix 77 beads. Shown below is a graph with 8, 10, and 12 turns through the toroid – obviously more turns has higher choking impedance. Mix 77 toroid products are HERE and Mix 77 small beads (for small wires) are HERE

F240 77 Turns Comparison 1024x648 - AM Broadcast RFI Kits

F240-77 Turns Comparison from .1 – 8.1 Mhz

Shown below is a graph of frequency response verses choking magnitude for a F240-77 in the AM Broadcast band for a 12 turn coil around the toroid. (Same info as above but different frequency range).