[TenTec] omni v short dits

Bob Henderson bob at cytanet.com.cy
Mon Jul 26 10:12:49 EDT 2004 

I deduce from your mail that you're not overly impressed by Idiom Press and
their K3 keyer!  I don't own a K3 and have no relationship with Idiom Press.
I do use a Samson ETM9 which is a Logikey circuit, similar I believe, to the
K3.  I point all of this out as I am now going to disagree with you  pretty
much 100%.

There is a world of difference between weighting and keying compensation.
Though at a given speed it is possible to adjust either for a similar
sounding effect.  It is the speed change that you make after the weighting
adjustment that causes things to come apart at the seems.

Weighting is the duty cycle of a string of dots.  It is adjustable on most
modern keyers in the range 25-75%.  Good code is dot weighted at 50%.

Keying compensation changes key down to key up time by a fixed number of mS
completely independent of sending speed.

Weighting was originally talked about when mechanical bugs were the norm.
These keys frequently clipped dots and or made unclean breaks at the end of
dots.  All of these were mechanical problems.  The rigs of the day had a
different, though complementary tendency to extend character elements.  Of
course rigs then didn't have microprocessor control and tended to be either
cathode or grid block keyed.  Back in those days with cathode keyed rigs the
steps you took to avoid key clicks were not only to remove the clicks caused
by the rig but also by the unclean make and break tendency of the mechanical
bugs contacts.  In classic fashion the tendency was to soften the rise and
fall of the carrier wave at the start and end of character elements.
Sometimes this was done to what by today's standards, would be considered
extreme ammounts.  Didn't you ever set up a bug using an ohmeter so you
could see it was producing 50% duty cycle but then find it sounded either
heavy or scratchy when keying the rig?  Scratchy because of the bug contacts
or heavy because of the time constant added to get rid of the scratchy
effect.  Frequently, I would find that weighting would need to be set at
40-45% at the bug to produce 50% on air.  (Elements extended through click
reduction measures).  The big problem was that weighting set at 25 wpm was
no good at all if the speed was increased to 50 wpm.  It's easy to see
why.........

Say for example, you have a dot length of 40mS with keyer weight set at 50%
but that this sounds heavy because of your rigs wave shaping time constant.
You reduce your weighting to 40% to restore a 50% weighted on air signal
from the transmitter.  Having done this, your keyer dot length would be 32mS
to produce an on air 50% weighted 40mS dot.  In this scenario your TX is
extending character elements by 8mS.  Quite common in the "Old days".  Now
you double your speed and half your keyer dot length to 20mS.  What happens?
Well your keying sounds heavy again.  Why?  Because your 40% weighting is
shortening your dot by only 4mS to 16mS now but your TX is extending your
dot by 8ms meaning that on air your dot is 24mS long.  To restore an on air
50% weight you would have to reduce your keyer weighting to 30%.

By now you can probably see that keying compensation is a much better
scenario.  If your rig extends by X mS you want your keyer to shorten your
elements by X mS.  On the other hand if your rig truncates character
elements by X mS you will want your keyer to extend elements by X.

Earlier firmware in the Orion truncated character elements by around 8-10mS.
I got around that problem with my keyer which I programmed to extend
character elements by 8mS.  This fixed the problem regardless of sending
speed.  I could have achieved a similar result by adjusting weighting but I
would have had to readjust it every time I changed keying speed.  Not nearly
as convenient.

The 8-10mS element truncation on the Orion is now a thing of the past, so I
have deleted the 8mS extension from my ETM9C programming.  I believe Orion
still truncates by around 2-3mS but that is not significant at the speeds I
work.  Never these days do I send above 50 wpm.  If I did and I was
concerned about it then it only takes a moment to program a 2 or 3mS delay
into my ETM9C.  I can do the same in Writelog for computer generated code
for contesting.  Interestingly the author of Writelog has confused matters
somewhat by referring to what is a keying compensation adjustment in the
program as a "Weighting " adjustment.

So there you have it.  If I have explained myself adequately, you will now
understand the difference between weighting and keying compensation.  Who
knows you might even conclude the folks at Idiom are not quite the Idiots
you thought. I guess the corollary is that if my explanation doesn't work
for you then you'll just add me to the Idiom Asylum.

Bob, 5B4AGN, P3F


----- Original Message -----
From: "Steve N4LQ" <n4lq at iglou.com>
To: <tentec at contesting.com>
Sent: Sunday, July 25, 2004 4:49 PM
Subject: Re: [TenTec] omni v short dits


> This is really so simple and the K3 propaganda has folks confused.
> Simply put. Some rigs chop dits. Your keyer makes a nice heavy dit and the
> rig shortens it.
> There is a cure....Increase the weight of your keying.
> You can do this with most any elcheapo MFJ keyer.
> Idiot Press's K3 not only has a weight setting but what they call a
"keying
> compensation" adjustment. They are blowing smoke about the "delay" issue
> just to make you think their keyer has something that others don't.
> Here is proof to the doubters.
> Listen to yourself on another receiver. Try changing the weight and
> compensation and LISTEN. You will see that they do EXACTLY the same thing
to
> your signal. They are duplicate controls.
> The only difference is in the sidetone of the K3 keyer. The sidetone will
> follow the weight control but not the compensation setting.
> People gobble up this compensation talk like it's the final cure for their
> QSK ills and rate the K3 very high while all along it has no advantage to
> other keyers and in fact, I found the timing of their "mode B" to be
> slightly different than a real Curtis chip and am able to key with less
> errors on the real thing. 73
> Steve N4LQ
> ----- Original Message ----- 
> From: "Tommy" <aldermant at alltel.net>
> To: <tentec at contesting.com>
> Sent: Sunday, July 25, 2004 11:52 AM
> Subject: Re: [TenTec] omni v short dits
>
>
> > It must be Sunday because my brain cell just can not tell the difference
> > between increasing the key-on time and decreasing the key-off time, and
> > changing the weight ratio of a character.
> >
> > If you delay the key closure, you are not keying anything, so how does
> that
> > increase something that has not started yet?
> >
> > If you delay the key closure to "decrease the keying-off  time", how can
> you
> > decrease the off time of something that has not started?
> >
> > Maybe this is one of those things that are much harder to explain the to
> > actually do? The radio is not going to (obviously) start producing RF
> until
> > the key is closed, so if your delaying the time before you close the
key,
> > the radio is just sitting there staring at you, until you actually close
> the
> > key.
> >
> > I think I need a beer. At least it's something to ponder for the rest of
> the
> > day. Make that two beers!
> >
> > Tom - W4BQF
> >
> > ----- Original Message -----
> > From: "Don Watters" <ve1bn at eastlink.ca>
> > To: <tentec at contesting.com>
> > Sent: Sunday, July 25, 2004 9:45 AM
> > Subject: Re: [TenTec] omni v short dits
> >
> >
> > > Steve -
> > >
> > > You asked   "How does the rig know it's "make" is being delayed by a
> > keyer?"
> > >
> > > It's the reverse,  the key closure is delayed to increase key-on time,
> or
> > > decrease
> > > keying-off time,  by the amount of mS you set to match the rig's on
> delay.
> > > The
> > > adjustment is independent of speed and is used to correct keying
> > distortion
> > > of
> > > various transceivers.
> > >
> > > You will note that ARRL tests of key closure versus signal transmit
> delay
> > of
> > > different rigs are shown.   I measured the mS needed to compensate my
> > > rigs from those test pix.  The Paragon II was "dead on" using the
> Paragon
> > > (1)
> > > test results.  Saved a lot of fussin".
> > >
> > > 73 -  Don   VE1BN at eastlinbk.ca
> > >
> > >
> > >
> > > ----- Original Message -----
> > > From: "Steve N4LQ" <n4lq at iglou.com>
> > > To: <tentec at contesting.com>
> > > Sent: Saturday, July 24, 2004 9:17 PM
> > > Subject: Re: [TenTec] omni v short dits
> > >
> > >
> > > >
> > > > Yes sir. I had a K3 Super Duper CMOS here for some time. I sold it
> > because
> > > I
> > > > didn't like the mode B emulation. Other than that, it's ok.
Listening
> to
> > > the
> > > > weight vs. "keying compensation" adjustment in another receiver,
they
> > > seem
> > > > to do exactly the same thing which is to increase the length of the
> > > > characters. The only difference is that the "keying compensation"
> > doesn't
> > > > affect the K3's racus sidetone.
> > > > Now I have a question about one of your statements.
> > > >
> > > >  "Keying compensation allows the make to be delayed so that the
start
> of
> > > the
> > > > > rig's
> > > > > keying envelope matches the keyer.   The weight control is
> different."
> > > >
> > > >  How does the rig know it's "make" is being delayed by a keyer?
> > > >
> > > > Anyway, for some rigs, especially ICOMS, when used in QSK mode,
extra
> > > weight
> > > > is needed. When I use my MFJ 407 with the PROII in QSK mode, I
simply
> > > crank
> > > > up the weight control about 30%. In Semi-bkin mode, I turn it back
to
> > > > normal. The sidetone in the PROII reflects this change and sounds
> rather
> > > > heavy. When using the K3 keyer, you get the same exact effect when
> > > > increasing either the "weight" or "compensation". If you can stand
to
> > > listen
> > > > to the sick duck sidetone of the K3, the weight of the sidetone is
> > > preserved
> > > > by increasing the "compensation" instead of the "weight". So
basically
> > the
> > > > "compensation" adjustment is a gimmick.
> > > > Most TenTec rigs do not seem to require additional weight but las
Tom
> > > > mentioned, the Omni 6+ does need a little help over about 45 WPM.
The
> > > Orion
> > > > seems to be rather unpredictable in this reguard. Mine was choppy at
> > first
> > > > then I upgraded the software and it sounded much better but my QSK
> > became
> > > > slow. Maybe there's a relation!
> > > >
> > > >
> > > >
> > > >
> > > > Steve N4LQ
> > > > ----- Original Message -----
> > > > From: "Don Watters" <ve1bn at eastlink.ca>
> > > > To: <tentec at contesting.com>
> > > > Sent: Saturday, July 24, 2004 7:45 PM
> > > > Subject: Re: [TenTec] omni v short dits
> > > >
> > > >
> > > > > Whatever, Steve.  Please don't  take me for a fool.  Guess I am
just
> a
> > > > lucky
> > > > > fellow
> > > > > with a CMOS Superkeyer 3 which can compensate keying in various
> rigs.
> > > > Ever
> > > > >  try one?  Was a cmcl op, used a bug for 40 years from early ham
> days
> > in
> > > > > 1946
> > > > > until I sold my little Zephyr 5 years ago. I've used the CMOS for
> the
> > > past
> > > > > 9.
> > > > >
> > > > > Guess I'm a true blue CW op too!!     I know you don't tighten the
> > dits
> > > up
> > > > > on a bug
> > > > > as close as suggested.
> > > > >
> > > > > Keying compensation allows the make to be delayed so that the
start
> of
> > > the
> > > > > rig's
> > > > > keying envelope matches the keyer.   The weight control is
> different.
> > > It
> > > > > shortens
> > > > > the spacing of characters, sort of runs them together if too much
> > weight
> > > > is
> > > > > set.  Big
> > > > > difference.  These are heard in the Ten-Tec sidetones.
> > > > >
> > > > > Was just suggesting a possible solution, but forget it OM,  you
> > > apparently
> > > > > already
> > > > > have the answers....
> > > > >
> > > > > By the way, no offence taken or meant.
> > > > >
> > > > > 73 -  Don  VE1BN at eastlink.com
> > > > >
> > > > > Gosh. just seems to do the job.      ----- Original Message -----
> > > > > From: "Steve N4LQ" <n4lq at iglou.com>
> > > > > To: <tentec at contesting.com>
> > > > > Sent: Saturday, July 24, 2004 8:06 PM
> > > > > Subject: Re: [TenTec] omni v short dits
> > > > >
> > > > >
> > > > > > Keying compensation? Delay? Sounds like a line from the K3
manual.
> I
> > > > > suppose
> > > > > > if he had a  keyer he could crank up the weight  but I'm not
sure
> > the
> > > > ole
> > > > > > boy owns one. He's a true, blue cw op! Bug only! BTW: That
"keying
> > > > > > compensation" is just another weight control. The only
difference
> in
> > > > that
> > > > > > and a regular weight control on a Curtis keyer is the fact that
it
> > > > doesn't
> > > > > > affect the sidetone (which few people use anyway).
> > > > > > Steve N4LQ
> > > > > > ----- Original Message -----
> > > > > > From: "Don Watters" <ve1bn at eastlink.ca>
> > > > > > To: <tentec at contesting.com>
> > > > > > Sent: Saturday, July 24, 2004 6:19 PM
> > > > > > Subject: Re: [TenTec] omni v short dits
> > > > > >
> > > > > >
> > > > > > > Hi Steve -
> > > > > > >
> > > > > > > Any way he can set the keying compensation?   I found my
Paragon
> > II
> > > > > needed
> > > > > > > about 15 mS delay to give a smooth keying characteristic. No
> > > shortened
> > > > > > makes
> > > > > > > or clicks.  Worth a try if he can set it up.
> > > > > > >
> > > > > > > 73 -  Don,  VE1BN at eastlink.ca
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > ----- Original Message -----
> > > > > > > From: "Steve N4LQ" <n4lq at iglou.com>
> > > > > > > To: <tentec at contesting.com>
> > > > > > > Sent: Saturday, July 24, 2004 6:30 PM
> > > > > > > Subject: [TenTec] omni v short dits
> > > > > > >
> > > > > > >
> > > > > > > A friend of mine has an Omni V and he is trying to use a bug
> > however
> > > > the
> > > > > > > dits are being chopped so badly that he can't use it. I've
never
> > had
> > > a
> > > > > > > TenTec rig that chopped dits like this one. I've hear him on
the
> > air
> > > > and
> > > > > > > even with his dit weight screwed to almost touching, he sounds
> > > > horrible.
> > > > > > > It's like something is wrong in the keying circuit. Has anyone
> > > > > experienced
> > > > > > > this?
> > > > > > >
> > > > > > > Steve N4LQ
> > > > > > > _______________________________________________
> > > > > > > TenTec mailing list
> > > > > > > TenTec at contesting.com
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> > > > > > >
> > > > > > >
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> > > > > >
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