Model SB-1 is a static bleeder meant for 50 or 75 ohm coax line. It is rated from 1-150 Mhz at 1.5KW with a maximum SWR of 5:1 on the line. The bleeder is used on a coax “T” in line with the coax transmission line as shown in the picture below.
SB-1 Coax Static Bleeder installed on coax “T” connector
To use procure a coax “T” and a male to male connector. Connect the SB-1 to the male to male connector and thence to the coax “T”. Static voltages are bled off from the center conductor to the outside conductor (braid of the coax). At the entrance to your radio station ensure that the outside conductor of the coax transmission line is grounded so as to provide a sink for the static electricity on the antenna center conductor.
The SB-1 static bleeder is usually installed near the radio shack entrance on the antenna side of any 1:1 baluns/line isolators (between isolator and radio) if used.
the connector is a male PL-259 and will fit into a SO-239 (female) or "T" with female counterpart to the PL-259. Small, convenient, effective and easy to install! "T" connector shown in picture NOT included.
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 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).
F240-77 Choking Impedance in AM Broadcast Band
Typical Installations for Donut/Ring Toroids
 AC Cable on F-240 Toroid – 6 turns |
 Ethernet Cable on F-240 Toroid – 7 turns |
 Audio or Mic cable on F240- 12 turns |
Extra Mix 75 Snap On Beads HERE – VERY effective for AM Broadcast RFI