Propo Gurus: Does Sporadic E block lower freq. signals?

Discussion in 'The DX Zone' started by KQ9I, Jun 13, 2021.

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  1. KQ9I

    KQ9I Premium Subscriber QRZ Page

    The last few days we've had some good sporadic E and 6m has been hopping. However, I seem to note that the lower bands (20-15m) are very...anemic during these sporadic E openings. Is that coincidence, or does the E layer absorb some of the lower frequency signals, particularly DX signals?

    Ionogram of E opening today (central US)

    Jim KQ9I
  2. M0YRX

    M0YRX Ham Member QRZ Page

    The sporadic E clouds do not absorb the lower frequencies such as 20-15m that you mention and these bands could open to short skip via E,s much sooner than 6M gets a sniff , what it can do is blanket those lower frequencies from ever reaching the F layer or for a particular hop distance. The signals could still well be refracted to somewhere but the distances could well change . Hope that helps.
    K0UO likes this.
  3. M0YRX

    M0YRX Ham Member QRZ Page

  4. KQ9I

    KQ9I Premium Subscriber QRZ Page

    So if I understand you correctly, the E layer doesn't absorb those lower frequency signals, but it can reflect them back, resulting in much-reduced skip distance as compared to the higher F layer? The effect being that 20-15meter signals are regional instead of being open for DX?

    K0UO likes this.
  5. M0YRX

    M0YRX Ham Member QRZ Page

    Yes , although maybe not just regional but as the E layer is lower for the same take of angles compared to the F layers the distance covered by each refraction is shorter . This could lead to more ground reflections for same distance covered.

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