The RFI-HDTV RFI/Noise solution kit is specifically designed to cure most HDTV external interference issues triggered by Radio Frequency Interference problems generated by AM/FM, CB and Ham radio transmitters or other consumer electronic devices. The ferrite filters are selected to eliminate RFI from 1 to 300 MHz. The ferrites are easy to use, don’t require modification of the protected equipment and work in almost all cases. The RFI-HDTV kit contains a selection of ferrites including 1 ring filter for AC power and 4 3/8" snap on filters for input/output cables such as HDMI, video, cable/satellite input, audio, etc. RFI occurring at lower frequencies typically comes through the AC power lines acting as “antennas” picking up the interference signal and these ferrite filters have been specifically selected to suppress this interference. An instruction sheet is included with typical installation examples. This kit also works on computer monitors experiencing RFI. If you have a sophisticated home theater systems with multiple devices such as DVD players, cable/satellite input, OTA antennas, audio amplifiers, consider the RFI-HTS which includes many more filters for multiple devices. TECH NOTE: We also stock RFI kits to protect effected devices such as garage door openers, computers (laptops, desktops), dsl/cable routers, ethernet hubs and many more devices.Remember there is always a “transmitter” and a “receiver” of RFI and the quest is to find and choke the “path” the RFI has selected – you need to add ferrites to both the transmitting side and the receiving side to eliminate RFI problems. The RFI-HTS kit only helps suppress RFI on the receiving side. Typical RFI Problem/Solution: Hi Larry, Your RFI problem is quite common and is usually a sign of either a radiating coax feed line or reception of your radiated signal (source) by the Direct TV (the victim) through either the AC power lines acting as “antennas” for your ham signal or the coax braid of the satellite antenna acting as an antenna for your signal. The solutions are straight forward using our home theater system RFI kit.
Hello,
I am Larry, a ham operator and I am having interference issues with
my Direct TV system.
My station is a FT450D through an Ameritron ALS-600. From the amp
through a coax switch to choose between an OCF dipole or an Hustler
5BTV vertical. Any power over 100 watts and my DTV goes off the air
and must completely reboot/format. Coax is RG-8. The DTV dish is
pointed away from the dipole and separated by about 25'. DTV was
totally useless! They suggested I not talk on the radio while she is
watching TV! Please help me with a reasonable, cost effective
soultion. (The wife gets really pissed when I shutdown the tv!)
Thank you,
Larry
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.