[Elecraft] K3 CW speed request

[Andrew Faber]

Drew,
  I don't think that is correct.  Normal CW has a dash that is three times 
as long as a dot. If you have dashes as short as twice as long as dots, the 
code sounds very strange.  The ratio, i.e., three to one, is purely of the 
length of the character.  Normal spacing between dots and dashes is one dot 
length, independent of the dot to dash ratio.  If the transmitted code 
sounds OK, and the dashes are truly as long as you say, then the speed 
control is mis-calibrated.
  I note that the K3 has a menu entry for what they call CW Weight, defined 
as the dot to space ratio (although often CW weight is used to mean the dot 
to dash ratio). Not sure if there is a way on the internal keyer to vary the 
dot to dash ratio. Most outboard keyers allow you to play with the dot to 
dash ratio, and some people like to vary it a bit from three to one.

  73, Andy, ae6y.
----- Original Message ----- 
From: <drewko1 at verizon.net>
To: <Elecraft at mailman.qth.net>
Sent: Thursday, July 03, 2008 7:57 AM
Subject: Re: [Elecraft] K3 CW speed request


> Dahs are actually twice the length of dits, I think. Or technically,
> the dah period is twice the dit period (i.e., a dah sound plus its
> space is equal to two dit sounds and their spaces).
>
> I measured the dahs instead of dits because I don't have a keyer; just
> pluged my mono straight key plug into the paddle jack and it gives
> dahs.
>
> I measured the period by averaging over five dah periods with the K3
> readout set at 22 wpm and 21 wpm, giving periods of  0.207s and
> 0.219s, as mentioned. I measured the sidetone at the headphone jack
> using audio waveform software.
>
> 73,
> Drew
> AF2Z
>
>
>
> On Thu, 03 Jul 2008 07:39:55 -0700, andy, ae6y wrote:
>
>>Those dashes sound a little long.  The formula normally used to calculate
>>lengths of  elements is
>>dot length (msec) equals 1200 divided by wpm.
>>  Thus, at 22 wpm, the dot length should be 54.5 msec.  Dashes are 
>> normally
>>three times as long, i.e., 163.5 msec.
>>  73, andy, ae6y
>>----- Original Message ----- 
>>From: <drewko1 at verizon.net>
>>To: <Elecraft at mailman.qth.net>
>>Sent: Thursday, July 03, 2008 6:58 AM
>>Subject: Re: [Elecraft] K3 CW speed request
>>
>>
>>> On Thu, 03 Jul 2008 13:53:14 +0100, David G4DMP/G3KEP wrote:
>>>
>>>>In a recent message, charles <m0bin at m0bin.demon.co.uk> wrote ...
>>>>>Is it possible to have a speed step of .5 in between the present CW 
>>>>>speed
>>>>>settings of whole numbers?
>>>>>
>>>>>I am particularly looking for a CW speed of 21.5 wpm just now.
>>>>
>>>>Charles, I doubt that the tolerance of the K3 displayed speed is better
>>>>than +/- 0.5wpm, so you may find that 21 or 22wpm could be just the
>>>>speed you are looking for.  Have you measured it accurately?  Your
>>>>findings would be of interest here.
>>>>
>>>>73
>>>
>>>
>>> I measured the sidetone dah lengths at the speaker:
>>>
>>> A 22wpm dah is 0.207 sec; a 21wpm dah is 0.219 sec. Not sure about the
>>> conversion to wpm but I think this comes out to 24 wpm and 22.8 wpm
>>> respectively; could be wrong.
>>>
>>> 73,
>>> Drew
>>> AF2Z
>>>
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>>
>
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