Download the MFJ-704 Manual If your harmonics are causing TVI problems, an MFJ-704 could keep your neighbors happy while you have fun hamming. MFJ's Super Low Pass filter simply plugs between your rig and antenna. It suppresses TVI, RFI, telephone and other interference by reducing unwanted harmonics going to your antenna. At the same time your HF signal passes on through with low loss so you can snag rare DX. Nine Chebyshev poles, MFJ's exclusive TeflonDielectric Technology capacitors, Hi-Q inductors, ground plane shielding and an RF tight cabinet give you excellent TVI and RFI protection. These exclusive Teflon Dielectric Technology capacitors give you extremely low loss and eliminate voltage breakdown and capacitor heating -- even at full legal power with a 2:1 SWR load! The result You get the lowest possible loss, excellent harmonic attenuation and years of trouble-free and TVI-free service. Handles full legal power from 1.8 to 30 MHz. SWR below 1.3 to 30 MHz into 50 Ohms. Attenuates above 40 MHz. Measures a compact 3x3x9 inches. Handy mounting tabs.