TVI & RFI Suppression

1/2" Snap-on cores are no longer available. We are now using .41" i.d. cores which are the ideal size for RG-213, 9913, 9096, and similar cables with the outside jacket diameter of RG-213. The .41" cores provide tighter coupling and thus are more effective.

The RADIO WORKS™

The RFI QUICK FIX™

Line Isolators™

The first line of RFI Quick Fix™ defense.

Tip for finding the source of RFI and cables carrying stray RF

Use the MFJ-805 or MFJ-854 (preferred) to find the wires and cables carrying unwanted stray RF in and out of your shack and equipment. Then use either the MFJ-701 “break apart” toroid cores or use our new and highly effective RFI cores (preferred). These cores have “snap-together” baskets which securely hold the core halves together. Combine these with our famous Line Isolators, and you have the latest weapons for the fight against RFI.

These are the "big guns" in the attack on RFI. They can help on both transmit and receive.



{short description of image}

{short description of image}

The RFI Quick Fix™

The "First Step" and often the only step in many "RFI Quick Fix" solutions

The RADIO WORKS' Line Isolator™

Here are the details.
The RADIO WORKS' Web Store available from this link.

Snap-on Ferrite Cores are a Must Have in the Ham Shack.

NEW!

.41" i.d. Snap-on Core

Just the right size for a perfect, snug fit on RG-213 size cables, which include, 9913, 9086, 9096, LMR-400, Super 400, RG-213, RG-8, etc. This insures maximum coupling and maximum performance.


Four snap-on cores are shown on each cable. In some cases, more may be needed. Each core provides around 150 ohms of inductive reactance at most HF frequencies.

.25" i.d. cores fit RG-8X and similar size cables.
.41" i.d. cores fit RG-213 size cables. These include 9913 types or any cable with an outside diameter under 0.41"

Snap-on Ferrite Cores

Featuring #31 Ferrite Mix - the best for this purpose

Up to this point, nearly all RFI beads were made with #73 material. As you can see from the chart above, it was useful from 1 through about 25 MHz. To cover the frequencies up to 300 MHz you would have to switch to #43 material. Now, at the RADIO WORKS, our new RFI “core,” which replaces about 6 beads, covers the spectrum from below 1 MHz all the way up to 300 MHz. Just as important, the impedance of the new bead is higher than previous types.

We stock Ferrite Cores in the two most popular sizes with inside diameters with .25” or .41". Both cores use the new #31 ferrite material. If you use some other ferrite mix, you won't get the best results. Also, you have to use a lot of Ferrite beads to equal these snap-on cores which are about 1.25" long.



.25” Ferrite Snap-on Core - fits RG-8X, RG-59, and any 1/4” cables including smaller power and rotator cables.


.41” Ferrite Snap-on Core - made for a snug fit on RG-213 size coax which is .402" in diameter. This includes 9096 SuperFlex, RG-213, RG-8, 9913, etc. The snug fit improves RFI attenuation. Use for any wire or cable up to .41" or for multiple turns of smaller wires
RADIO WORKS'™ WEB STORE

Available at the RADIO WORKS'™ Web Store

.25" i.d. "snap-on" core $ 2.50 each
.41" i.d. "snap-on" core $ 4 each

Another useful Snap-on Ferrite tool - the Toroid.

MFJ-701

MFJ -701

RFI-free Choke Kit
Package of four core sets

.5 MHz to 200 MHz. These break-apart toroids have a wonderful reputation at solving difficult RFI problems. Wrap power cords, coax, input/output line onto these cores and get ready for amazing results.

RADIO WORKS'™ WEB STORE

Available at the RADIO WORKS'™ Web Store

Snap-on toroids, pack of 4 $26.95
Caution

Caution: In mobile installations, it may not be safe to use your radio equipment when your vehicle is in motion. RFI can affect your vehicle's onboard computer. Check with the vehicle's manufacturer.
Grounding




Most Important - Most Overlooked
Grounding is Critical


6" Ground Rod Strap

Grounding is the critical step in RFI and RF feedback elimination.

Without proper grounding, solutions are difficult. It's important to know the difference between RF and electrical or d.c. grounding. For important details be sure to read the information in Jim's Notebook.
RADIO WORKS'™ WEB STORE

Available at the RADIO WORKS'™ Web Store

½ BRAID Tinned-copper braid, per foot $ 0.95
1" BRAID Tinned-copper braid, per foot $ 1.69
6" copper rod strap to attach ground braid to ground rod $ 1.49

If You Have Difficult Grounding Problems, These Can Be Very Helpful.

MFJ-931

MFJ-931 Artificial RF Ground

Creating an artificial RF ground effectively places your rig near actual earth ground potential even if your rig is on the second floor or higher where no earth ground is possible. It reduces chances of TVI & RFI. The MFJ-931 creates an artificial RF ground. It resonates a random length of wire thrown along the floor and produces a tuned counterpoise. When used with a conventional ground system, the MFJ-931 places a far away RF ground directly at your rig -- no matter how far away it is. It reduces the electrical length of the ground connection wire to virtually zero by tuning out its reactance. Tune with the built-in RF ammeter. 1.8 - 30 MHz.
RADIO WORKS'™ WEB STORE

Available at the RADIO WORKS'™ Web Store

MFJ-931 Artificial ground $99.95

{short description of image}
You'll need a jumper cable to connect some of these devices.

Return to Web Store Index
RADIO WORKS™ Web Store

Back to Home Page
Back to Web Store Index
To top of page
{short description of image}
{short description of image}
{short description of image}