[Ham-Mac] Slightly off topic, history of 850 Hz shift?

[D. J.]

According to my copy of The New RTTY Handbook (1962) by Byron H.  
Kretzman, W2JTP, the reason for 850 was an FCC standard imposed in  
Feb, 1953 permitting FSK (F-1) with a speed of 60 wpm and 850 cycle  
shift plus or minus 50.  Why the FCC chose 850 it doesn't say.  Maybe  
bandwidth and equipment capabilities, just a guess.

73

Dale, K9VUJ



On 28, Sep 2006, at 11:13, Bob Nielsen wrote:

> I recall that hams also used 850 Hz shift when I first operated  
> RTTY over 40 years ago, although 170 was starting to gain favor  
> about that time.  The bands were less crowded then.  There were  
> also wire-service (AP or UPI) transmissions just above the 20 meter  
> band in those days, although you could go through a roll of paper  
> pretty fast listening to them.
>
> 73 - Bob, N7XY
>
>
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