![]() ![]() For 500 ohms we would need 5 mix 31 beads or 6 mix 43 beads to have greater than 500 ohms. For example if you have a 50 ohm RG-8 coax cable and want a choking impedance of 500 ohms at 10 Mhz, you can check the FB102 column (since FB102 will pass RG-8 through its center ID) at 10Mhz and find that Mix 31 has a Z of 108 ohms/bead and Mix 43 has a Z of 91 ohms/bead. Visit our website for all your RFI/noise reduction needs!Īpplication Note: Use impedances for each bead at your desired frequency to select number of beads needed for desired Z. We stock RFI/Noise Reduction kits for most brands of radio transceivers and generic kits for others If you use a linear amplifier use a Palomar Engineers amplifier RFI kit for additional RFI interference suppression. Snap on ferrites may be either 4 or 6 sided depending on inventory - they have identical electrical properties.įor additional RFI suppression, use a feed line choke at the antenna feed point to suppress common current on the coax feed line during TRANSMIT and a CMNF-500-50 coax noise filter at the radio end of the coax to reduce common mode noise during RECEIVE. Quick installation - immediate RFI/noise reduction. Kit Includes 2 noise reduction ring filters for coax and AC/DC power and 3 snap on filters for I/O cables. The ferrite split beads and ring filters are easy to use, don’t require modification of the protected equipment and work in almost all cases, even when plug-in filters fail. These chokes use a ferrite core material that is effective in suppressing RFI from transmitters and receivers experiencing a high noise floor in the 1-300 MHz range. ![]() ![]() The DC power line filter helps keep common mode current out of the power line which could cause interference to other devices connected to the same power source. These filters help cure SWR problems between transceiver and a linear amp and between transceiver and antenna tuner or direct to antenna. RFI from other electronic devices such as switching power supplies, LED and fluorescent lights, battery chargers, Ethernet cables, solar systems, kitchen appliances, and cable/satellite TV systems which generate common mode currents on your radio cables.ģ. ![]() Radio Frequency Interference (RFI) to electronic devices including audio/video systems, computers, telephones, garage door openers, alarm systems, and home appliances, in your house or your neighbor’s house.Ģ. If you have an RFI problem in your shack, then one of these MFJ-915 RF Isolators, now available from DX Engineering, may be the answer you need.BUY THIS KIT NOW TO SOLVE YOUR RFI PROBLEMS! WORKS WITH MANY BRANDS OF HAM/COMMERCIAL HF RADIOS INCLUDING ICOM 7300.ġ. The entire assembly is enclosed in schedule 40 PVC pipe for maximum strength and protection. The coax and SO-239 connectors have PTFE insulation which extends the life of the product. These RF Isolators are made up of 50 Ferrite Core Beads, placed onto a 13-inch piece of RG-303 coax. Use of MFJ-915 RF Isolators will increase the efficiency of all HF amateur stations. Stray RF also results in a loss of radiated power from the antenna, which will cause a reduction in radiated signal strength. If strong enough, this current may cause RF burns or other problems with electronic equipment in ham shacks and vehicles. MFJ RF isolators reduce or eliminate stray RF often found on coax shields. They were designed to improve the performance of all amateur stations, fixed or mobile. These RF Isolators are effective from 1.8 to 30 MHz at full SSB legal power. MFJ-915 RF Isolators are 1:1 ferrite chokes designed to be placed in line with 50-Ohm coax. ![]()
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