This RFI kit is specifically designed to suppress interference triggered by today's smart appliances used in the kitchen and household that act as "transmitters" and affect other appliances or radio/TV/Cable audio systems OR these appliances may act as "receiver" of energy from other devices such as ham radio, CB, AM broadcast and other electronic devices in the home. The problem is generally the AC power cable acting as an "antenna" picking up or transmitting signals. The RFI kit has ferrite filters are selected to eliminate RFI from 1 to 300 MHz and are typically used on the AC power lie of your Washer, Dryer, Microwave, Refrigerator and AC powered Clocks and Lamps. The filters are easy to install, don’t require modification of the protected equipment and work in almost all cases. The RFI kit contains 3 ring filters (1.4" ID), 1 large snap on (1" ID) and 2 smaller (1/2" ID) snap on filters for clock or lamps. Installation examples are shown in the included manual. Simple, easy to install and effective in almost all conditions.
What is included in the kit?
Iron powder cores are more stable than ferrites and do not saturate as easily so they are best for tuned circuits, filters, and high power inductors. They come in different “Mixes” for use at different frequencies. For best “Q” use the Mix specified for your frequency.To find the number of turns to give the desired inductance for your coil use the formula below:
Turns = 100 x 
Toroid Dimensions
To order specify core size and mix (e.g. T200A-2). Available in sizes that have µH per 100 turns shown in table.
All iron powder cores are special orders. Please allow one week for shipment after order received.
The iron powder cores shown in the above tables are primarily used for either high power feed line chokes for common mode current reduction or for 4:1 and 9;1 very high power transmission line transformers.
For high power feed line chokes, choose the inside diameter of the iron powder core closest to the transmission line outside diameter and use 6-20 cores at the junction with the antenna feed.
For 4:1 (50/200 or 75/300 ohm) transmission line transformers in the range of 1.8-30 Mhz, select the size appropriate for the power level as follows:
T200A x 2 = 1.5KW
T300A x 2 = 2.5KW
T400A x 2 = 5KW
Use Mix 2 for all the above transmission line transformers. Fully assembled and enclosed units are available for each of the power levels. Click HERE for information.
4:1 transmission line transformers using iron powder cores are typically used for ladder line to 50 ohm coax connections
For .1 – 2 Mhz wide band transformers use Mix 26 which has a higher permeability and requires less turns to achieve a given inductance. Mix 2 has almost constant permeability from 1-30 Mhz. Mix 26 has an initial permeability of 75 at .1 Mhz and gradually decreases to about 10 at 30 Mhz. For high power AM broadcast range (.5-1.7 Mhz) transformer, use Mix 26 to reduce the turn count.
Minimum order for iron powder cores is $50
Shipping on larger cores in quantity may be more than $10 – email/call for quote.