Feedline System · Common-Mode Control
The 500W Mini Line Isolator
Half of what you hear as noise never came in through the antenna. It came in on the outside of the coax braid, walked past the tuner, and climbed into the receiver. A current-mode choke is the part that stops it.
The Mini is the right choke for the great majority of stations: 100 to 500 watts, multi-core multi-turn ferrite, 1 to 61 MHz, in a package small enough to hang at a feedpoint or tuck behind the radio without a bracket.
The Build
| Power rating | 500 W PEP |
| Frequency range | 1 to 61 MHz |
| Choking impedance | 500 to 5000 ohms across 1 to 60 MHz |
| Common-mode attenuation | 20 to 35 dB, depending on band |
| Insertion loss | Approximately 0.25 dB |
| Connectors | SO-239 female, in and out |
| Enclosure | 3 in long, 2 in wide, 1.25 in high |
| Made in | United States |
Mini or Maxi?
Run the numbers, not the nerves. If your station puts out 500 watts or less, this is the correct part and the extra money buys you nothing. If you run an amplifier, heavy digital duty cycle, or a very long feedline, step up to the 3500W Maxi Line Isolator.
Worth knowing before you buy anything: every Greyline feedline kit already ships with slip-on bead choking. The Mini is for operators who want a dedicated isolator at the feedpoint, at the shack entry, or both.
Not sure which choke your station needs? Call us at 435-200-4902. Tell us your power, your feedline length, and what your noise floor is doing, and we will tell you honestly whether you need this one, the Maxi, or neither.
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