[TenTec] Re: CW Practice on Omni

[Steve Ellington N4LQ]

In the old days, to adjust the weight on a keyer, I would put an ohmmeter
across the keying relay, set the speed up to about 40wpm, hold down the dot
lever and adjust the weight control for 1/2 scale on the meter. This was the
accepted practice and I believe can be found in the ARRL Handbook.

This worked fine for REAL transmitters but when "timed sequence keying",
transcievers and QSK came along, delay was introduced in the transmitter
which shortened the characters and forced us to increase the weight of the
keyer.

>From scope patterns I've seen, the TenTec rigs do induce some delay but they
make up for it on the trailing end and the result is a faithful reproduction
of the keyer. I think you would be safe using the ohmmeter in this case.
Don't bother trying it on a IC-706 or FT-990 !

An observation: The faster the code, the less weight you want. Why: because
it's easier to copy due to the fact that there is more time between
characters thus giving the brain more time to distinguish between dits and
dahs. Some keyers automatically decrease weight as speed is increased.

73 N4LQ Steve



>Your comments on weight control have educated me.  I always assumed that
>weight control meant the ratio of the length of a dash to a dot.  The morse
>code generating programs I have written these many years, starting with the
>C-64 back in '83, all identified weight control as the ratio of the length
>(in millisecs.) of a dash relative to the length of a dot.  My timing
>constants kept the length of a dot constant with respect to the length of
>the key-up time following a dot.  I varied the length of the dash by
>changing its time constant, thus breaking away from the desired 3 to 1 dash
>to dot ratio.
>
>Now I suppose I will have to go back and dig out all that old source code
>and change it.
>
>With some effort because of the clutter on my desk, I was able to plug my
>keyer into the keyer line on the back of my Omni.  Varying the "weight"
>control did seem to vary the weight of both the dot and dash, making them
>progressively lighter as the weight decreased below 1.00, and progressively
>heavier as it went above 1.00.
>
>My Logikey keyer has the ability to adjust keying weight.  Their manual has
>a blurb  about weight, which includes the following sentence. "Weight is
>the duty cycle of a continuous string of dots, which is 50% for perfect
>code."  Changing the weight on the Logikey produces the same result as on
>Omni VI.  In neither case, as far as I can tell, does the length of a dash,
>relative to the length of a dot, stretch out.
>
>Thanks for bringing this up.  I don't hope to change all of those dusty old
>programs, but perhaps I can change my most recent one.  I think I will keep
>both settings, but call the stretched dash something else, like the
>"vibrosimulator" feature.
>
>Well, back to listening for rare DX.
>
>Pete.
>
>
>At 12:59 1999/01/12 -0500, Steve Ellington wrote:
>>
>>Why do some internal keyers allow control of the dash to dot ratio and
>>they bill it as a "weight control"? Facts are, the dot/dash ratio is
>>supposed to always be 1:3. They teach that in code class. There is a big
>>difference in that and weighting. Weight has to do with the length of both
>>characters and the ratio stays constant.
>>
>>Being able to change weight is important. Some rigs tend to chop the
>>characters such as the IC-706 but when you look a the keyer's menu, there
>>is nothing to change by ratio whichis of no use.
>>
>>What I'm wondering is this: Did the design engineers suddenly
>>misunderstand what cw is about or are they just not capable of designing
>>the keyer correctly?
>>
>>I built a little curtis chipped keyer into my TKIT 1340 and it has a real
>>weight control. Ratio is fixed as it should be. What's the dea;?
>>
>>N4LQ
>>
>
>Amateur Radio Station NO2D
>Pewee Valley, KY
>http://members.iglou.com/pinskeep
>Ask about my free Linux Morse401.tgz program
>


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