The Ferrite Ring Combo Pack is a convenient solution for troubleshooting RFI/EMI from unknown frequencies or multiple frequencies that require multiple suppression mixes. Included in this combo pack are ten 2.4″ OD/1.4″ ID ring toroids as follows:
Mix 75 effective from .15-10 MHz including AM Broadcast band – quantity: 3
Mix 31 effective from 1-300 MHz for general purpose – quantity: 4
Mix 61 effective from 200-2000 MHz for cell phone, WIFI, HDTV, Cable TV interference – quantity: 3
1500 Watt PEP rated 4:1 Current Balun + internal 1:1 Current Balun in one enclosure
After many requests we have created a compact, special balun for OCF and loop (Skyloop or Delta loop) antennas. The CB-4-1500OCF is a CUBE enclosure containing a multi-core, broadband 4:1 impedance transformer in series with a 1:1 current balun for extra common mode current choking to keep RF current off the outside of the coax braid and on the antenna where it belongs. The extra choking action also means that the coax feed line will not act as a radiator causing unnecessary RF interference (RFI). Rated for full 1500 watts PEP and 450 watts CW/FT8/RTTY (ICAS). 1.8Mhz – 61 MHz.
The CB-4-5000OCF (5KW PEP) have a frequency range of 1.8-31 MHz and does not cover 6 meters.
CB-4-1500OCF is housed in a 4” x 4” x 2” waterproof housing with SO-239 input and stainless steel eye bolts on the side for ease of connection to your wire antenna. Top eye bolt acts as an antenna hoist. Use this balun combination when you DO NOT have a vertical radiator.
5KW are in 6" x 6" x 4" enclosure. 1.5KW is 3 pounds, 5KW is 5 pounds. Note the 5KW models are made to order and shipment time is approximately 7-10 days after order date.
For a 135 foot 80 meter OCF, we recommend a 29.5%/79.5% offset for best all band results. If you use 66%/34% offset, do not use on 15 meters as the impedance mismatch may damage the balun under high power operations
The ring toroids are useful for AC/DC common mode choking with multiple turns as shown below
 AC Cable on F-240 Toroid – 7 turns |
 DC Cable on F240 – 4 turns |
The ring toroids can also be used on coax or signal lines as shown below:
 RG58 12 turns on FT240 |
 Ethernet Cable on F-240 Toroid – 7 turns |
For RFI/EMI wrap as many turns as possible for higher choking (under 30 mHz).