The simplest, most cost effective feed line choke is a ferrite ring installed as shown in the picture (at the antenna feed point) to stop feed line radiation or at the radio end of the coax to suppress common mode coax noise current on the coax braid.
Great choke for log periodics, HF beams, Transceiver/Amp isolation
Improves antenna pattern by preventing your dipole from becoming a tripole
Suppresses pesky coax braid radiation and RFI
Reduces coax braid common mode current up to -40 dB ( 6 “S” units) on receive
Use one choke for each antenna feed line
Add a double female barrel connector to act as an “extension” of the existing coax.
FT400-3I, ID=3", RFI Range 1-300 MHz
| Quantity | Price per item | Discount |
| 2 items | $37.95 | 5% off |
| 10 items | $34.95 | 13% off |
(4″ OD, 3″ ID hole), available in mix 31 only
Excellent for large cables or multiple cables – use multiple cores for higher choking. Also useful when you need high turns count for high choking with large cable - works on AC or DC power lines and also coax cable lines.