MFJ-704 Legal Limit Low Pass Filter


The MFJ-704 Legal Limit Low Pass Filter is an indispensable tool for radio amateurs seeking to enhance their HF operation from 1.8MHz to 30MHz. Crafted with utmost precision, this full-size low pass filter guarantees virtually no loss within its extensive frequency range, ensuring a truly immersive and harmonics-free transmission experience.

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Experience crystal-clear communication with the MFJ-704 Legal Limit Low Pass Filter, specially designed for radio amateurs seeking unparalleled HF operation. Meticulously crafted to cover a broad spectrum from 1.8MHz to 30MHz, this full-size low-pass filter ensures minimal signal loss and guarantees harmonics are effectively suppressed – allowing you to transmit with confidence.

Say goodbye to frustrating interference caused by TVI, RFI, or telephone lines as the MFJ-704 expertly eradicates these nuisances. Equipped with our exclusive PTFE Dielectric Technology capacitors, this filter elevates your transmission capabilities like never before. Seamlessly handling full legal power across the range of 1.8 – 30 MHz, it effortlessly maintains SWR below 1.3 into a standard 50 Ohm configuration.

Transforming your amateur radio experience into a professional endeavour is now effortless when harnessing the esteemed performance of the MFJ-704 Legal Limit Low Pass Filter.


  • RF Connector Type: UHF female, SO-239
  • Filter Impedance: 50 Ohms
  • Filter Frequency Range: 1.8 – 30 MHz
  • Cutoff Frequency: 40 MHz
  • Minimum Attenuation: 60 dB at 52 MHz
  • Pass Band Insertion Loss: 0.50 dB at 30 MHz
  • Power Handling: 1.500 W

Additional information

Weight1.1 kg