[Milsurplus] NAF 68304 Nay Beam Filter

[Al Klase]

D C *Mac* Macdonald wrote:
> I am not absolutely certain, but I believe that the tone
> frequency used was actually 1020 Hz, supposedly because
> research had shown that a tone of that frequency gave
> the strongest response in the average human ear for a
> given actual sound pressure.
>
> Mac, K2GKK/5
> Oklahoma City

I don't know about that, but 1020 is an even multiple of 60Hz making it 
easy to calibrate from the AC line frequency.

Al

-- 
Al Klase – N3FRQ
Flemington, NJ
http://www.skywaves.ar88.net/