DX Engineering Ferrite Linear Amplifier RFI Suppression Pack #1, model DXE-LA1-RFI, has four mix-31 ferrites that are intended to provide chokes on HF amplifiers that have four cables. This kit includes one Large Toroid, two Large Snap-On Beads and One Medium Snap-On Bead. They provide RF choking that can reduce RF noise as well as help prevent erroneous meter and display readings, false keying and reduce erratic amplifier operation due to RFI. To prevent the pickup of stray RF, the ferrites are placed on cables as close to the amplifier as possible. Wrapping multiple turns of a wire or cable through and around the ferrite increases the RFI suppression. Although some effort is involved with winding more turns of a wire around half of the snap-bead core before closing it, a much greater degree of RF suppression is achieved. Each ferrite snap-on bead cover has a small flap on one half that engages and snaps onto the other half to keep it closed, which gives it the name Snap-On Bead. Here is how to apply DX Engineering Ferrite Linear Amplifier RFI Suppression Pack #1 at the rear panel of the amplifier that has four cables:1. Wrap 5 to 9 turns of the RF input RG-8X coaxial cable through and around the Large Toroid2. Coil 3 turns of the RF output RG-8U size coaxial cable and clamp with one Large Snap-On Bead3. Coil 3 turns of the AC power cord and clamp it with the second Large Snap-On Bead4. Wrap as many turns as possible of the keying cable from the transceiver for the amp relay around half of the Medium Snap-On Bead and close it to clamp the wraps of cableClose the ferrite snap-on beads onto the wires coiled or wrapped around half of the bead close to the rear panel of the amplifier. If desired, electrical tape may be used to hold coiled cables or wires and beads in place. For increased RFI suppression, additional beads may be placed at on the cables at the rear of the amplifier and at the transceiver.