AM Broadcast RFI Kits

MINI-BALUN 1:1 Coax Interface to Ladder Line, Dipole elements, 500 Watts PEP, up to -38Db Common Mode Rejection, 1-61 MHz, Flagpole, Dipole, Beam and G5RV/ZS6BKW Antennas

SKU MB-1-500SS
$69.95
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MINI-BALUN 1:1 Coax Interface to Ladder Line, Dipole elements, 500 Watts PEP, up to -38Db Common Mode Rejection, 1-61 MHz, Flagpole, Dipole, Beam and G5RV/ZS6BKW Antennas
Product Details
Brand: Palomar Engineers
MPN: MC-1-500SS
Country/Region of Manufacture: United States
Effective Frequency Range (MHz): 1.8-60
PEP Power Rating (watts): 500 SSB (25% duty cycle), 250 Watts CW/FT8 (50% duty cycle)
Common Mode Attenuation (db): 20-38db
Estimated Insertion Loss (db): .25 db
Input Connector Type: SO-239 female
Output Connector Connector Type: Dual 1/4" stainless steel studs
Ground Connector (Y/N): none
Enclosure Size (LxWxH inches): 3" long, 2 in wide, 1.25" high

MINI-BALUN Features:

- Uses proprietary Multi-Turn ferrite technology for maximum choking (up to -38 dB common mode noise rejection) and maximum bandwidth

- 500 Watts PEP, 50 ohm SO-239 connectors In, Dual Side Stud Output, 1.8-61 MHz (usable to 100 MHz) - AKA 1:1 BALUN

- Works for all coax fed antennas from 1.8-61 MHz (160-6 meters) - excellent for multi-band beam interface, G5RV/ZS6BKW or Flag Pole OCF antennas fed with ladder line.

- 2-5 times more common mode noise rejection, wider bandwidth and higher power then competing isolators

MINI-CHOKER feed line chokes are used to suppress common mode current carried on the outside of the coax braid which is often responsible for receiver noise and RFI in the receiver/transmitter. These chokes are very useful for suppressing RFI common mode current at the antenna feed point, at 1/2 wavelength intervals along the coax feed line and also at the entrance to the radio station.

This choke has a SO-239 input and 1/4" top studs output.

For Higher Power needs use our MAXI-CHOKER with dual stud outputs in 1.5KW or 3KW version part# MC-1-1500LL, MC-1-3000LL

If you need a unbalanced output (SO239 output) instead of a balanced stud output, see MC-1-500 with SO239 output and input..






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).

AM Band Choking Graph F240 77 1024x648 - AM Broadcast RFI Kits

F240-77 Choking Impedance in AM Broadcast Band

 

 

Typical Installations for Donut/Ring Toroids

20131210 114716 150x150 - AM Broadcast RFI Kits

AC Cable on F-240 Toroid – 6 turns

20131210 115137 150x150 - AM Broadcast RFI Kits

Ethernet Cable on F-240 Toroid – 7 turns

20131222 125533 150x150 - AM Broadcast RFI Kits

Audio or Mic cable on F240- 12 turns

 

 Extra Mix 75 Snap On Beads  HERE – VERY effective for AM Broadcast RFI