AM Broadcast RFI Kits

CUBE 1:1 Feed Line Choke Balun, 5KW, 1.8-61 MHz, -38dB Common Mode Rejection, Eyebolts/Top Studs Options

CB-1-5000EB
$139.95
In stock
1
Product Details
Brand: Palomar Engineers
Effective Frequency Range (MHz): 1-61 MHz
PEP Power Rating (watts): 5000
Estimated Insertion Loss (db): .10
Input Connector Type: SO-239 female
Output Connector Connector Type: top studs or side eyebolts
Ground Connector (Y/N): none
Enclosure Size (LxWxH inches): 4 x 4 x 4

5000 Watt rated 1:1 CUBE™ BALUN

* Help keep RF out of the shack.

* Provides maximum transfer of RF to the antenna.

* Suppress radiation from the feeder cable

* Makes the antenna radiation pattern predictable.

* Reduces QRN and TVI to the neighbors.

This higher power BALUN or UNUN utilizes mil-spec coax cable for the windings on a triple core toroid with coax silver shield and silver braid for low loss. The dielectric is Teflon® insulation for high voltage ratings of 1,900 volts. (A typical 5KW signal at 50 ohms impedance will have a voltage of 500 volts at 1:1 SWR). Available wired as a BALUN (CB-1-5000) with wire studs output or as a UNUN (CU-1-5000) with SO-239 input and output connectors. Rated 5KW PEP/1500 Watts AM/RTTY/CW/FT-8 from 1.8-30 Mhz, less at 50 Mhz. Enclosure is 4" x 4" x 2"

If you run RTTY contests at 1500 watts output, this is the balun/unun you need – it won’t burn out at heavy 1500 watt duty cycles like other brands rated at 1500 watts (or more). We use these same chokes in our own RTTY station at full 1500 watts output and they have never failed. We use one at the amplifier output and another at each antenna feed point. Works very well on OCF antennas below the 4:1 balun to keep RF current on the antenna and off the feed line. Built like a tank, works like a charm, and priced under the competition – what more can you ask for? THIS IS OUR MOST POPULAR 1:1 BALUN!

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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