[TenTec] [Orion] O2 versus Orion

[Sinisa Hristov]

Gary Hoffman wrote:

> Has not a thing to do with your ability to hear, say, a 30 Hz tone.  The
> thrummm that you hear, while I never measured it, is at a much higher
> frequency than that....perhaps a  couple hundred Hz or so.  But it Varies
> very slowly in amplitude over time - that is, at the beat frequency.


With equal amplitudes we have:

 COS (x) + COS (y) = 2 * COS ((x + y) / 2) * COS ((x - y) / 2)

Example:
  freq 1 = 800.10 Hz
  freq 2 = 800.00 Hz

  what one hears is an 800.05 Hz tone with its amplitude
  varying from zero to twice the single tone amplitude (+6 dB)
  at a rate of 0.05 Hz, which means that peaks (or throughs)
  are separated in time by 10 seconds (once per 0.05 Hz half-period).

This a well known physical phenomenon, not related to hearing at all.

The resolution depends mainly on source stability and one's patience.


73,

Sinisa  YT1NT, VE3EA