[MacLoggerContest] Fun with theology

Don Agro dagro at dogparksoftware.com
Mon Mar 14 07:29:40 EST 2005


Hi Chuck, Bill,

On 14-Mar-05, at 6:37 AM, Chuck Counselman wrote:

> Don:  I am taking the liberty of forwarding Bill Coleman's message to 
> you.  IMO, he is correct.
>
> The importance of this is not for calculating the number of 
> milliseconds in a dit; it's for generating code that's legible.
>
> -Chuck, W1HIS

MacLoggerDX does in fact pause 2 dit intervals between characters PLUS 
4 dit intervals between words resulting in a total of 6 dit intervals.

The people who tested this found it perfectly copyable.

This tangent arose because of the (incorrect I feel) assertion that 
accurately timed CW could not be generated in software on a Mac.

I was merely using K3MT's reference to show the approximate operating 
system granularity required to generate accurate CW at 32 WPM.

Now if I base my calculations on an average word size of 48 dit spaces 
and someone else says that the average word size is 50 dit spaces it 
really doesn't matter - except that our words per minute may vary by 
around 4% - but the relationship between MacLoggerDX's dits, dahs and 
spaces is still fixed at an accurate and copyable ratio timed to the 
fraction of a millisecond.


> At 11:44 PM -0500 3/13/05, Bill Coleman wrote:
> On Mar 13, 2005, at 11:14 PM, Chuck Counselman wrote:
>  Don Agro got 48 as follows:
> http://users.erols.com/k3mt/morse/cw.htm
>   the dit - two dit spaces long
>   the dah - four dit spaces long
>   the letter space - two dit spaces long
>   the word space - four dit spaces long.
>
>  AH! I see the error -- the Word space is 4 dit spaces long -- IN 
> ADDITION TO the character space.  The total off time should be 7 
> elements long.
>
> If you send morse with a word space only 5 elements long, your words 
> will run together and copy will be harder.
>
> In your case, the word space is 9 elements long, which is a bit too 
> long, but too long is far better than too short.
>
>  I have in my hands the twelfth edition of "Learning the 
> Radiotelegraph Code", as published by the ARRL in 1970. (Old enough 
> not to have an ISBN, but it is Library of Congress catalog number 
> 55-8967)
>
>  In chapter 2 - Learning to Send, it has a chart on Page 17, which 
> lists the relative sizes of the components of code:
>
>  Dit = 1
>  Dah = 3
>  Element space = 1
>  Character space = 3
> Word space = 7
>
> It then gives an example -- the text "IN ALL" charted according to 
> these rules. There are clearly 7 element intervals between the end of 
> the last element in a word, and the first element of the next word.
>
>  Bill Coleman, AA4LR, PP-ASEL        Mail: aa4lr at mac.com
>  Quote: "We invented personal computing."
>              -- Bill Gates @ TechNet / MSDN 2003
>
>




73 Don Agro VE3VRW

D o g   P a r k   S o f t w a r e   L t d .

email: dagro at dogparksoftware.com
   www: http://www.dogparksoftware.com
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