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Whistlers on the HF bands

Discussion in 'General Technical Questions and Answers' started by KC8VWM, Oct 9, 2010.

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  1. KC8VWM

    KC8VWM Ham Member QRZ Page

    Does anyone remember the phenomenon known as "whistlers" occurring on the HF bands?

    Apparently it's a "noise" that occurs in your radio receiver similar to a "whistling signal sound" and it's supposedly caused by a geological disturbance occurring in the earth's environment.

    I used to experience these unusual "whistling" sounds that would quickly shift in frequency on the HF bands many years ago, but not recently.

    Do they still occur?

    What do you know about them?
    Last edited: Oct 9, 2010
  2. AI6DX

    AI6DX Ham Member QRZ Page

    I just remember hearing "whistlers" in local bars. :D:D:D

    Seriously though, I've heard of "birdies" as in "auditory interference" associated with electrical or RF interference. but not "whistlers."

    I've also heard of "Whistler" radar detectors.
  3. K8MHZ

    K8MHZ Ham Member QRZ Page

    I thought it may have been spread spectrum.

    One day I had 2 HF rigs on, one a few kc from the other. I could hear the whistlers go from one rig to the other. IIRC, they always went up in frequency.
  4. W8JI

    W8JI Ham Member QRZ Page

    There are whistlers at ULF (near audio) that are associated with lightning and polar disturbances, but none I've ever heard about at MW and higher.

    There are also ionospheric sounders and industrial devices that sometimes can be heard.

    In Ohio I had a problem with an industrial heating device at a plant that used plastic packaging. It would whistle as the machine loading changed and the self-excited oscillator would move. This happened because some idiot removed the shields to make the machine easier to service. Silly Hams in the area attributed the packing machine to all sort of weird things, from sun spots to the moon.

    There have been a few transmitters doing something similar. Harris (I think) made a low level modulated transmitter than had a 5CX3000 in the PA. It was terribly unstable and a local transmitter at WTTO used to sweep the 160 meter band with a moving parasitic. WOHO had one also, and their's also oscillated.
  5. W5HTW

    W5HTW Ham Member QRZ Page

    Haven't heard them in many years. But I do vaguely recall them. I think I read somewhere in something like Popular Science, they were noise reflections off meteors passing by. Certainly feasible, but I don't think anyone really knew.

    Of course, it could have been receiver design back then, but I doubt it. Every once in a while a whistler would pass through your frequency and you had not changed any settings.

    I'll go with the meteor theory. Something to do with the speed of the meteors as they hit our atmosphere? Or their mass? Or their metallic content?

    There are so many noises on the HF bands these days, though, strange signals, like the one I can't describe except as clicks or chirps moving up or down through a frequency. Possibly OTHR? Or frequency transponders? MUF checkers? Back in the mid 1960s when I was with the government, we operated some point to point transponders to determine the best frequency to use for certain communications. But we dismantled all that by 1965, I think.

    Another thread mentions background noise on ten meters. I think the response is yes, it is noise from inside our solar system, primarily Jupiter. It has pretty much always been there.

  6. KJ4HAY

    KJ4HAY Ham Member QRZ Page

    I'm aware of lightning "whistlers". This site has some sound files of these recorded with a VLF receiver:
    I got there from a Wikipedia article about radio whistlers that I cannot get to link properly here.
  7. W0LPQ

    W0LPQ Ham Member QRZ Page

  8. W8JI

    W8JI Ham Member QRZ Page

    You probably heard an ionospheric sounder use to measure the ionosphere, although it could have been a runaway transmitter.

    The atmosphere itself is not a source of things like that, and neither are things in space.

    Lightning and other disturbances can cause whistlers on ULF, but the junk moving around on HF is pretty well all man made.
  9. K8JD

    K8JD Ham Member QRZ Page

    I recall wanting to build a reciever for ULF whistlers, "the dawn chours", and other upper atmospheric RF phenoms that occur naturally. It consisted of a local oscillator that operated in the ultrasonic frequencies and a mixer that fed a high gain audio amp...Somewhere along the way I lost interest in this ...
    This variety of strange signals was presumed to originate in the spiraling path of ions around the earth's magnetic field. The source of the particles may have been energy from lightning strikes.
    Yes Carl and Jerry inspired many of my younger persuits...Then I started meeting GIRLS !
    Last edited: Oct 9, 2010
  10. N0SYA

    N0SYA Ham Member QRZ Page

    on 80m they call it the ufo
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