Re: microphone hum

Yup, 15734 Hz is NTSC. On a clear day I can pick this signal up from a
distance of 100+ meters. This is surprising since high frequencies
have much more attenuation in air than lower bass frequencies. Just
shows how loud the retrace can be and how adaptable the human brain is
at notching noise signals out.

For an audio file, a spectrogram, some analysis, and a bit of TV
flyback fun see:

http://www.baudline.com/mystery_signal/12_answer.html

Enjoy,

.

Relevant Pages

  • Re: Fet scope probe design recommendations
    ... > scope to RF work only and even then at points in the board where the ... > being much use to check signals from any hi-Z impedance source! ... standard 10MEG 10X probe, or a FET or bipolar active probe. ... At high frequencies, the circuit impedances are low so a resistive ...
    (sci.electronics.design)
  • smoothing the hilbert transfoms output?
    ... I?m monitoring real sinusoidal signals of 50Hz, ... frequency and amplitude waveforms [which are wrongly triggering my ... have either low or high frequencies (and I have to save both, ... amplitudes are totally disappeared in the smoothing process. ...
    (comp.soft-sys.matlab)
  • Smoothing the ripples from hilbert tr outputs?
    ... I?m monitoring real sinusoidal signals of 50Hz, ... frequency and amplitude waveforms [which are wrongly triggering my ... have either low or high frequencies (and I have to save both, ... amplitudes are totally disappeared in the smoothing process. ...
    (comp.soft-sys.matlab)
  • Tropical Bands from a Tropical Land - Puerto Vallarta, Mexico
    ... to Puerto Vallarta. ... conditions each morning seemed to skip 41 and 49 meters; only a few signals ... printout of the DSWCI's Tropical Band Monitor, ...
    (rec.radio.shortwave)
  • Re: The NOG - AFSPC Media Telecon for IIR-20M (svn 49, prn 01) problem
    ... and the second at an elevation of 90 degrees. ... I'm sure they're wishing they had a far field antenna cut on this puppy; ... comes from a different combination of the signals emanating from the 12 or ... Since several meters is multiple wavelengths, ...
    (sci.geo.satellite-nav)