SESKStuff Everyone Should Know
SESK: Stuff Everyone Should Know · sesk.info/hamg-lsb-why

Why do most hams use lower sideband on 160, 75 and 40 meters?

Commonly accepted practice, not a rule.

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  1. Lower sideband is the only legal sideband there
  2. It is commonly accepted amateur practice ✔
  3. Lower sideband is more efficient there

Why: Nothing in the FCC rules requires it. Using LSB on the lower bands and USB on the higher ones is simply a tradition that makes everyone's radios line up.

Huh, didn't know that: In SSB, only one sideband is transmitted, and the other sideband and the carrier are suppressed.

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References

Answer: It is commonly accepted amateur practice. Nothing in the FCC rules requires it. Using LSB on the lower bands and USB on the higher ones is simply a tradition that makes everyone's radios line up.

  1. NCVEC 2023-2027 General Class Pool and Syllabus (6th Errata, Feb 4 2026) ncvec.org/downloads/General%20Class%20Pool%20and%20Syllabus%202023-2027%20Public%20Release%20with%206th%20Errata%20Feb%204%202026.pdf
    It is commonly accepted amateur practice
    Checked 2026-10-10.

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Ham RadioWhich sideband is most common for voice on 14 MHz and higher?Ham RadioOn which HF bands do General licensees have some off-limits portions?Ham RadioOn which of these bands is voice (phone) operation prohibited?

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