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Author Topic: Weight in  (Read 2854 times)
KI6LZ
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« on: May 07, 2014, 02:08:07 PM »

I'm confused on what parameters to set regarding weight and spacing of dots and dashes. Someone told me that as the speed increases starting at around 35 wpm it is good practice to slightly increase the dot length. If I increase the dot length should I also increase the spacing between dots or keep them the same? Does anyone change their parameters at higher speeds? For me the dots get harder to control and also copy at higher speeds.


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N3HEE
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« Reply #1 on: May 08, 2014, 08:36:27 AM »

I've never heard of doing that.  I doubt that will help much anyway.  At those speeds you are listening for sound patterns.  You should not be trying to keep track of dits and dahs.  As far as sending it's a matter of bug, key or paddle mechanical adjustment and practice developing better fine motor skills.  I'll be interested in hearing what others have to say.  -Joe
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WB2WIK
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« Reply #2 on: May 08, 2014, 09:31:11 AM »

I've never heard of doing that.  I doubt that will help much anyway.  At those speeds you are listening for sound patterns.  You should not be trying to keep track of dits and dahs.  As far as sending it's a matter of bug, key or paddle mechanical adjustment and practice developing better fine motor skills.  I'll be interested in hearing what others have to say.  -Joe

I agree.  I never adjust weighting to send at any speed, and do operate QRQ pretty often (high speed CW, >40 wpm).

Nobody's counting dits and dahs at higher speeds, they're copying letters, words and phrases.  For "plain English" conversation, mostly phrases and sentences.  I don't even think about letters.
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K8AXW
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« Reply #3 on: May 08, 2014, 09:32:37 AM »

LZ:  I have never heard of changing anything.....element length, spacing, etc. in my 58 years as a CW ham and 3 years of high speed Morse intercept.  

As HEE pointed out.... code is code and after the code is learned, the sound of the complete character is heard..... actually not heard  but  the sub-conscious mind simply responds to the sound.

If a person's brain can't recognize the complete character, which includes the dits, they can't copy that speed!

Change the sound and confusion sets in.  
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N2EY
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« Reply #4 on: May 08, 2014, 12:18:03 PM »

Dot weight should be 1:1

Dash weight should be 3:1

The way I check this is to watch the plate milliammeter on my rig while sending a string of fast dots and dashes. With the rig tuned up to 200 mA key-down, a string of dots causes the meter needle to hover around 100 mA (1:1 ratio) and a string of dashes to hover around 150 mA (3:1 ratio) if all is well.

---

In some rigs, however, the rig itself will do odd things to the on-off ratio at high speeds. The 'scope pictures in QST Product Reviews show this effect. Worth looking up your rig in the Product Reviews to see.

73 de Jim, N2EY
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N3QE
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« Reply #5 on: May 09, 2014, 07:34:07 AM »

I don't think there's any real reason to go messing with weight. I think with some older rigs, problems with keying (especially relay kick-in times) were sometimes worked around with by tweaking weight, but I don't think any modern equipment should need such tweaking.

Messing with weight certainly makes you more distinctive but not sure it makes you any more effective.

There are a couple prominent CW callsigns, mostly using bugs, who I can recognize purely by keying and part of that is weight. They may have a slight advantage in that their "distinctive sound" is known instantly by all the regulars. If you plan on being omni-present on CW and like playing with weight to get your own distinctive sound, sure, find what's best for you. I don't think you can quite get the "bug swing" just by playing with weight in an electronic keyer.
« Last Edit: May 09, 2014, 07:36:19 AM by N3QE » Logged
K8AXW
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« Reply #6 on: May 09, 2014, 11:06:49 AM »

On a personal note..... I feel that in this day and age there isn't any excuse for developing a "swing" or other distinctive fist. 

It's true that back in the day when the most advanced keying method was the bug, many would adjust and use them without concern with proper character length or proper spacing.

In the military 99% were required to use a hand key and it was always possible to learn a fist, or many fists on a circuit.  Actually, if an operator used a circuit for any length of time, it was possible to hear when an operator was changed, if an operator was drunk or sick.....and when he simply didn't give a damn!  Like on 3rd trick and just didn't want to be there.

Frankly, I wish everyone used a keyboard, or at least an electronic keyer.

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PA0WV
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« Reply #7 on: May 09, 2014, 02:59:58 PM »

Ki6LZ

I have some comments

Timing of Morse code is well known, and it makes the sound pattern.  All right.

BUT in order to prevent a wide band transmission, with key clicks all over the band, you need a slope of a few millisecond

Ideally this is a cosine squared slope.

In order to keep your mark space of a dit stream 1:1, the cosine square has to begin earlier, such that the amplitude is half way of the maximum at the official start (and stop) of the dit.  For that reason it may be that  you have to increase the mark/space ratio of your bug or keyer, such that an envelope detector of the transmitted carrier shows a ratio 1:1, which means that a linear analog meter oscillates exactly around half of the key constant down amplitude and the  'no signal' indication..

Extreme example to clarify my statement: when your slope is (pretty long) 5 ms from 0 to max, and the dits are 5 ms long, which is extremely high speed of 240 wpm, then the envelope of your antenna signal is a pure sine wave of 100 Hz, because the leading slope meets the trailing slope in top and bottom. You have then a carrier with two sideband frequencies at  100 Hz difference with the carrier. No click generated with this signal outside the bandwidth of 200 Hz.
« Last Edit: May 09, 2014, 03:05:04 PM by PA0WV » Logged

Using an appliance without CW is just CB
KI6LZ
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« Reply #8 on: May 09, 2014, 07:27:29 PM »

Thanks for the replies. I will take a look at shaping output to be sure. Also will try to record and play back some very nice code, at least to my ears, through a scope to see if I discern anything. Amazing that almost all rigs and keyers have adjustable code weighing and spacing parameters if 3:1 is a fairly hard standard.
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K8AXW
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« Reply #9 on: May 09, 2014, 09:15:55 PM »

This 3:1 isn't an exact science.  If a character or string of characters sound good, then 
you're close enough to the 3:1. 

I'm sure some have a reason for changing the weighing but I have no idea what that would be.

While I have never been able to copy 45wpm, I have heard recordings of CW sent at 45wpm and then played back at 1/2 speed.  The character formation and spacing was almost perfect.  The two operators apparently didn't find it necessary to change the weighing.

I've heard and recorded CW speeds in excess of 900wpm and the characters on the paper tape was perfect 3:1.  If anything was changed in the receiver or recorder, I have no idea. 
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KI6LZ
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« Reply #10 on: May 09, 2014, 09:26:41 PM »

Looking at the winkey instructions I see that weighting and dit to dah ratio are two different things.
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PA0WV
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« Reply #11 on: May 10, 2014, 02:04:22 AM »

Looking at the winkey instructions I see that weighting and dit to dah ratio are two different things.


When you define a dash as 3 dits mark and 1 dit space, and you define a dot as one dit mark and one dit space , then the dashmark dotmark ratio is 3.

However you can add  a percentage of the dit time to the dot mark and substract the same time from the dot space time.
So you can also do with the dash. That is defined as weighting. Because dot and dash time (including their accompanying space) don't change, this operation does not affect the Morse speed relation with the unmodified dit time..

The total dash time doesn't change in that case, because what was added to the dash mark is subtracted from the accompanying dash space.

So weighting is a dot related percentage, not dit related, in order to keep speed constant with dash marks of 3 dits, it is impossible to go below 2 dits for a dash-mark en 2 dits for a dash-space.

Another thing is changing the dot dash ratio,  when you make it larger dashes grow and dots are smaller (remember: including their accompanying spaces) That will make your speed always character dependent. (think of figures 0 and 5) I can't see a reason for doing that when weighting is already adjustable.

When it is included in a design, I suppose it is done just because "You asked for it" .






« Last Edit: May 10, 2014, 02:06:30 AM by PA0WV » Logged

Using an appliance without CW is just CB
K8AC
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« Reply #12 on: May 14, 2014, 05:46:09 AM »

Quote
I don't think there's any real reason to go messing with weight. I think with some older rigs, problems with keying (especially relay kick-in times) were sometimes worked around with by tweaking weight, but I don't think any modern equipment should need such tweaking.

If you look at the output of some of the modern rigs with the higher prices using a scope, you may be amazed at how far the dot to dot space ratio varies from 1:1.  I've often found the keying weight to be "light" when using QSK, but have also observed it in non-QSK mode (and this is true whether using an internal or external keyer).  And, even rigs that allow you to adjust the weight in 1% increments (TenTec Orion is one of them) will often be far off of 1:1 when the weight is adjusted for 100, which is supposed to be the 1:1 point.  Making weight judgements while listening to the rig's CW sidetone is a very bad idea.  In some rigs such as the FTDX-5000, the weight of the sidetone has little relation to that of the transmitted signal.  If you don't believe that, look at the weighting  by scoping the audio of the received signal on a separate receiver and comparing that to the sidetone audio. 
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KI6LZ
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« Reply #13 on: May 14, 2014, 12:44:42 PM »

I think you are on to something. When listening with an external receiver to my keying it just doesn't sound right. So I will dig out my scope and try to make some measurements. It makes sense that the keyer may not have the right weighing and ratio at different speeds and needs to be corrected.
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