[TenTec] Orion and Keyers

Ken Brown ken.d.brown at verizon.net
Mon Apr 4 03:23:47 EDT 2005


Hi Steve,

>http://www.n9vv.com/k7qo-a-b-keying.html
>
>that paper seemed pretty good.
>  
>
In that paper there is some mention of "the halfway point" in an element 
being the dividing line. If I am sending an "F" for instance, and I have 
the dit paddle closed at any time after the halfway point in the dah, 
then the trailing dit of the "F" will get sent. And if I release the dit 
paddle before the halfway point of the dah, then the trailing dit would 
not be sent, and a "U" would be sent, instead of an "F". At least that 
is the way I understand what he is saying.

If every keyer operating in Mode B operated exactly this way, then we 
would never notice any difference from keyer to keyer, and there would 
be no need for anyone to "adjust" to different mode B keyers. There are 
enough of us that have noticed a difference that we can make the 
resonable conclusion that not all Mode B keyers operate exactly the same.

I suspect that there are subtle timing differences in various Mode B 
keyers, such that the "halfway point" is not at exactly 50% through the 
dah. Dividing points in a dah may more conveniently occur at the 33.3% 
and 66.7% times within a dah, because the basic minimum element duration 
of a dit (or a space between elements) is 33.3% of a dah. I wonder if 
some Mode B keyers actually use 33.3% or 66.7% instead of 50%.

DE N6KB




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