[ARC5] Fwd: [R-390] FS: Radio Filter FL-30-M

[Roy Morgan]

On Nov 13, 2009, at 8:12 PM, Michael Bittner wrote:

> Also,1020 Hz is the 17th harmonic of 60 Hz.  Made it easy to  
> synchronize
> with the power line in the days before accurate oscillators.  Mike  
> W6MAB

>> "RANGE" is a narrow filter centered on 1020 Hz, if I recall, or  
>> whatever
>> tone was used for the Morse I.D. on range and LF beacon transmitters.

Yes it was 1020 cps.  I remember now the idea of the harmonic of 60  
cycles. I suspect that the 60 cycles was well standardized and very  
accurately controlled by the time the range navigation systems were  
developed.

I find that 1020 cps is a little high pitched for me now.   I seem to  
favor a tone of 700 to 800 cps for code copying.  Maybe when my speed  
gets up, I'll prefer a higher pitch.

Thanks for the comments.

Roy


Roy Morgan
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