Stephen Thomas Cole wrote:



Gents, can you please **** off.

If you have nothing to contribute to the discussion why join in at all?

My personal theory as to why few commercial morse keys use reed switches
or optical switches is that that users like to able to connect their
morse keys to a wide range of voltages and impedances, especially if you
include traditional valve equipment. Both technologies are intolerant
of excessive voltages or current compared with a pair of solid metal
contacts. I don't think either speed, latency or debouncing are
significant factors or, at least, they could be designed out.


--

Roger Hayter

On 18/11/2017 21:04, Roger Hayter wrote:
Stephen Thomas Cole wrote:



Gents, can you please **** off.

If you have nothing to contribute to the discussion why join in at all?

He expressed his frustration at not understanding
what was being discussed.

So much for the 3-tier "progressive" exam fiasco.

But, what else do you expect from any of the Four Amigos?

Gareth's Downstairs Computer wrote on 11/18/2017 4:48 PM:
On 18/11/2017 21:04, Roger Hayter wrote:
Stephen Thomas Cole wrote:



Gents, can you please **** off.

If you have nothing to contribute to the discussion why join in at all?

He expressed his frustration at not understanding
what was being discussed.

So much for the 3-tier "progressive" exam fiasco.

But, what else do you expect from any of the Four Amigos?

You seem to be the one slinging mud this time. I thought you never started
arguments?

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

On Sat, 18 Nov 2017 16:56:13 -0500
rickman wrote:

Gareth's Downstairs Computer wrote on 11/18/2017 4:48 PM:
On 18/11/2017 21:04, Roger Hayter wrote:
Stephen Thomas Cole wrote:



Gents, can you please **** off.

If you have nothing to contribute to the discussion why join in at
all?

He expressed his frustration at not understanding
what was being discussed.

So much for the 3-tier "progressive" exam fiasco.

But, what else do you expect from any of the Four Amigos?

You seem to be the one slinging mud this time. I thought you never
started arguments?


Another Chazalike.

Roger Hayter wrote on 11/18/2017 4:04 PM:
Stephen Thomas Cole wrote:



Gents, can you please **** off.

If you have nothing to contribute to the discussion why join in at all?

My personal theory as to why few commercial morse keys use reed switches
or optical switches is that that users like to able to connect their
morse keys to a wide range of voltages and impedances, especially if you
include traditional valve equipment. Both technologies are intolerant
of excessive voltages or current compared with a pair of solid metal
contacts. I don't think either speed, latency or debouncing are
significant factors or, at least, they could be designed out.

Not trying to be argumentative, but I'd like to understand the basis of your
point. Why would the three things above not be factors in using mechanical
switches in keys? Bouncing switch contacts do pose an issue for clean
keying of a transmitter, no? So the bouncing has to be smoothed out. That
means adding electronics which means interface specific again, no? I
supposed you could use a high voltage capacitor and no buffer. That would
be a simple RC with the R in series with the key to the controlled point.

Maybe I'm not grasping what you are saying. How do you see a simple
mechanical switch being used to control many types of equipment?

BTW, there are transistors available that will switch high voltages and
currents. So a simple interface circuit would serve for use with many types
of equipment and any type of key switch you wish to use.

--

Rick C

Viewed the eclipse at Wintercrest Farms,
on the centerline of totality since 1998

On 11/18/2017 12:44 PM, rickman wrote:
Jerry Stuckle wrote on 11/18/2017 10:50 AM:
On 11/17/2017 11:20 PM, rickman wrote:
Jerry Stuckle wrote on 11/17/2017 11:00 PM:
On 11/17/2017 6:57 PM, rickman wrote:
Jerry Stuckle wrote on 11/17/2017 3:23 PM:
On 11/17/2017 3:37 AM, rickman wrote:
Jerry Stuckle wrote on 11/16/2017 10:34 PM:
On 11/16/2017 9:17 PM, rickman wrote:
Jerry Stuckle wrote on 11/16/2017 9:02 PM:
On 11/16/2017 7:28 PM, rickman wrote:
Gareth's Downstairs Computer wrote on 11/16/2017 4:01 PM:
On 16/11/2017 20:04, rickman wrote:
Gareth's Downstairs Computer wrote on 11/16/2017 12:55 PM:
On 16/11/2017 17:07, rickman wrote:
Bob Wilson wrote on 11/7/2017 9:47 PM:
On 11/4/2017 5:42 AM, Gareth's Kitchen Komputer wrote:
On Mon, 21 Dec 2015 23:33:17 +0000, gareth wrote:

For those who make their own Morse Keys, what do you use
for the
contacts,
for
I have found the phosphor bronze pillar for the dot
contact
on my
ersatz
Vibroplex
to be very noisy and scratchy?

I'm fairly sure that I asked this question before, but
it has
been a
habit
of never put off till
tomorrow what you can put off till the day after.

I chose phosphor bronze because in the days of making
one's
own
electronic
organs, phosphor bronze was suggested as a suitable
keying
matreial
for
the
keyboards.






If a question's worth asking, Gareth...







I have not made lots of keys, but when I do I use
contacts from
old
relays.
I still have some relays I bought as WWII surplus when I
was
in my
teens,
back in the 1950's. They have strange coil parameters,
weird
mounting
arrangements, etc., but nice little silver contacts.
Bob W, WA9D

Why use a mechanical switch?Â* There are magnetic hall effect
switches
around.Â* Or a mercury wetted switch can be operated by a
magnet.
Are the
magnetic switches too sloppy?


Perhaps you confuse mercury wetted with reed relays?

I am thinking of reed relays, so I guess I used the wrong
name, but
aren't
they wetted with mercury to prevent corrosion building up?


In the closed atmosphere of the glass tube, there should not
be any
corrosion, I think. ISTR some gas in there, but don't know
about
mercury wetting.

Call it what you want, corrosion, oxidation, just plain
pitting.Â* The
point is a solid surface will wear from the arcing that
happens when
contacts break connections (which also happens on initiating
connection
because of switch bounce).Â* Mercury doesn't have this problem
as it
is a
liquid and reforms the layer every time it is "pitted".


Mercury also does not make a "clean" break.Â* It "puddles" as the
contacts
are pulled apart due to surface tension.Â* It leads to
irregular break
timing.Â* This isn't a problem at low switching speeds as you
have in
regular
switches and relays, but can be at higher rates as in CW.
Additionally a
magnetic field for switching accentuates this problem. Reed
relays are
good
for things like security system contacts, but not a CW key.

I haven't timed such switches.Â* What is the timing precision
requirement
for CW?Â* Does optical satisfy it?


Never tried optical but as long as you can get a clean
make/break of the
beam it should work.Â* The problem as i see it would be that clean
make/break; the beam will fade in and out.Â* Probably not as bad
as a
reed
switch - but for high speed CW you need clean operation.
That's why many keys use brass contacts or similar; the have a
clean
make/break.Â* And even if they get pitted they are soft enough to
burnish
rather easily and thick enough to last for years.

So no numbers?Â* Let's try to make some.

According to Tom - W4BQF, "All high speed code (above about 55
wpm) is
sent with a keyboard/keyer or a computer keyboard".Â* So we can
use 55 WPM
as an upper limit for using a manual key.

Dot length = 1.2 seconds / WPM = 1.2 / 55 ~= 22 ms

Switch bounce time for many switches is some single digit ms.Â* So
I'm not
sure what "clean" make/break means.Â* The bounce time for reed
switches is
about the same as other switches I found.


No, it is not bounce time - "clean" is how quickly it
makes/breaks. Brass
contacts are virtually instantaneous.Â* However, reed switches operate
via a
magnetic field.Â* This field is not a simple make/break - it gets
stronger
and weaker depending on the distance from the magnet. IOW, brass
contacts
are digital but the magnet field is analog.Â* The actual switching
does not
necessarily always occur at the same magnetic field strength.
Additionally,
switching off to on requires a stronger magnetic field than the
release.
The two combined can result in varying width pulses at high speed.
Optical
is also analog and can have similar problems.

And before you dismiss all of this - why don't you see any paddles
with
reed
switches or optical?Â* If these methods are so good, why aren't
they in the
high-end paddles/keys?

Whether or not reed switches are used in keys is not related to your
understanding of electronics.


It is.Â* That is the context in which they were brought up.Â* But I
know you'd
rather change the context than admit you are wrong.

There is nothing going on here except that you are mistaken about the
functioning of switches.Â* How about you address the issues rather than
diverting the discussion.


I'm not diverting the discussion.Â* You just don't understand how magnetic
and optical sensors work.Â* That is very obvious.

Go back and read.Â* I didn't say anything technical you said was off
topic. I was pointing out that what others do is not limited by you lack
of understanding.


You accused me of diverting the discussion. That means going off-topic.
Nothing of the sort.


Reed switches are *not* analog any more than mechanical switches in
that
they don't vary the connection continuously.Â* They are still metallic
switches and make or break when the metals touch.Â* The fact that the
magnetic field varies continuously is no different from the
pressure from
the paddle varying the position of the mechanical switch contact
"continuously".Â* I found no information indicating significant
variations
in the action of reed switches.Â* The variation in pull-in and release
field strength gives a small amount of hysteresis which is
desirable in
any switch.Â* It is not enough to distort the key times from one
character
to the next.


Reed switches are not - but the magnet field which triggers them
are. And
there is a huge difference between the magnetic field and finger
pressure on
a paddle.Â* That's exactly why reed switches are not used on paddles.

"There is a huge difference"... but you can't say what that
difference is.
The motion of the key paddle is analog which results in an analog
displacement of the mechanical switch until contact is made or in the
case
of a reed switch, results in the analog change in field strength
until the
threshold is reached where the switch pieces are pulled together.Â* All
analog until the switch pieces make contact which results in a discrete
output change.

The real difference is in the bounce time.Â* A mercury wetted reed switch
has no bounce time, contact is singular and certain.Â* A mechanical
switch
has a variable resistance until the point of contact stops moving and
settles down.Â* That's the bounce time.


I did tell you the difference.Â* But you called it off-topic.Â* This is not
related to bounce time.Â* But you can't get over that fact.

And you have failed to explain what *is* the problem.Â* Rather than
discuss the issue you are diverting.Â* Is there something you would like
to understand better?


I have explained the problems - in detail. But you're so full of
yourself that you can't understand the topic. But that's your style.


Likewise optical is only optical in the movement of the paddle and the
signal seen by the detector.Â* Once the signal passes through a
threshold
detector with hysteresis the signal is purely digital.Â* The strong
suit of
optical is that it eliminates all mechanical issues of wear and
failure.


The same is true for optical - except that optical can also be
affected by
ambient light, making the switch even less reliable.

Lol.Â* It is easy enough to exclude ambient light.


And how are you going to do that without restricting the motion of the
paddles?Â* Oh, I know.Â* You have this magical whatchamacallit that
creates a
black hole around the sensor and doesn't let any light in, while not
restricting any motion.

Right.

The mechanical force can be conveyed without light entering.Â* I guess
you've never used a camera with a mechanical shutter?Â* This wouldn't
require anything nearly as complex as that, but you do need to
understand the principle before you can see how it might be done.


Yes, and light enters the camera, doesn't it? You haven't explained how
to keep the light out without restricting the paddle. Not that I expect
you were able to do so.


I did a bit of reading about reed switches yesterday and they have
much
less bounce time than other switches and the mercury wetted types have
virtually no bounce time.Â* In fact while looking for info on typical
bounce times one of the pages I found showed a rather elaborate
circuit to
debounce the two mechanical switches in a keyer.Â* If the switches
were so
instantaneous, why would they need a debounce circuit?


Once again it isn't the bounce that causes the problem.

Bounce is a problem that makes the timing of the switch closure
uncertain
and must be eliminated.Â* Compensating for the uncertainly can't be done.
So what is the problem in mechanical switches if not bounce?Â* If a
switch
bounces for 5 or 10 ms, that is a significant portion of time for a
22 ms
dot.


THIS IS NOT RELATED TO BOUNCE!Â* GET OVER IT!

Actually, it *is* related to bounce as a debounce circuit is required
and typical debounce circuits create delay with undefined delays.
Instead of yelling what the issue isn't, how about you explain what it
*is*?


Nope. Nothing of the sort. Debounce circuits are for a different
problem. And I have explained the issue. You are just too full of
yourself to try to understand it. But that's what I expect from you, Rick.


Your analysis above shows a complete lack of understanding of how
switches
in general work and not just reed switches.Â* Try reading about
switches a
bit.Â* You will quickly find that metallic switches do not make or
break
cleanly with an "instantaneous" connection.Â* Just use google or any
other
tool to find some info on this and read it.


Nope, my analysis is right on.Â* And it is exactly why reed and optical
switching is not used in keys and paddles.

You actually haven't analyzed anything.Â* You just keep repeating the
same
unsupported conclusions ignoring the way mechanical switches operate.


I have, but you call it "off-topic".

You have not explained anything and I said nothing technical you said
was off topic.Â* You simply incorrectly stated that a magnetic switch is
analog (which actually makes no sense) because the field at the switch
varies in a continuous manner until the threshold is reached.Â* You
erroneously stated the mechanical switch (which a reed is also) is
"digital" because it is either open or closed, totally ignoring the fact
that a reed relay is uses mechanical contacts as well.Â* Both devices
have an analog input, the range of motion/force for the mechanical
switch and the magnetic field for the reed/Hall switch and a digital
output, closed or not closed.


You accused me of diverting the discussion - which would mean I'm going
off-topic. Nothing of the sort. And no, I did NOT say the magnetic
switch was analog. But you're just too full of yourself to even try to
understand what I'm talking about.


So if your ideas are so great, why
aren't there any high end manufacturers which have keys or paddles
with reed
or optical switches?Â* If they are as good as you say, I would expect
to see
dozens of them on the market.Â* Or maybe they know I'm right and you're
wrong.

Have you done a survey of all keys on the market?Â* I haven't.Â* Maybe
I'll patent the idea if no one is doing it.


All I ask if you is to show me keys which work that way. You can't even
show one commercial key which does. Go ahead and patent the idea. Then
see why it doesn't work.


Why don't you come up with your own paddles using them and market
them? If
they're as good as you say, you should make a fortune.

A fortune?Â* I don't think there is that large a market for any ham
product. Who has made a "fortune" selling anything to hams?


If they're as good as you say, sure there is. Over 700K hams in the
United States alone. If even 10% of them buy one of your paddles at
$100 each, that's over $7 Million. And if it's that good I would expect
at least that percentage to buy them.

But I know you won't. You have once again shown you don't have the MSEE
you claim from University of Maryland (you really should have picked a
school more than 10 miles from my QTH - too easy to go over there and
check). Even someone with a two year technical degree understands the
problems.

But this is normal for you, Rick. Go ahead and make a fool of yourself.
I'm tired of arguing with the idiot who tries to remain anonymous
because he doesn't want people to find out he really doesn't know
anything about electronics.

--
==================
Remove the "x" from my email address
Jerry Stuckle

==================

On 11/18/2017 1:00 PM, Stephen Thomas Cole wrote:

Gents, can you please **** off.


Yes, you wouldn't want an on-topic technical conversation on uk.r.a.!

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 11/18/2017 4:04 PM, Roger Hayter wrote:
Stephen Thomas Cole wrote:



Gents, can you please **** off.

If you have nothing to contribute to the discussion why join in at all?

My personal theory as to why few commercial morse keys use reed switches
or optical switches is that that users like to able to connect their
morse keys to a wide range of voltages and impedances, especially if you
include traditional valve equipment. Both technologies are intolerant
of excessive voltages or current compared with a pair of solid metal
contacts. I don't think either speed, latency or debouncing are
significant factors or, at least, they could be designed out.



That's another good point, Roger - although reed switches can easily be
connected to a wide range of voltages and impedances.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

On 11/18/2017 2:09 PM, Brian Howie wrote:
On Sat, 18 Nov 2017 12:44:38 -0500, rickman wrote:

Jerry Stuckle wrote on 11/18/2017 10:50 AM:
On 11/17/2017 11:20 PM, rickman wrote:

So if your ideas are so great, why
aren't there any high end manufacturers which have keys or paddles with reed
or optical switches? If they are as good as you say, I would expect to see
dozens of them on the market. Or maybe they know I'm right and you're wrong.

Have you done a survey of all keys on the market? I haven't. Maybe I'll
patent the idea if no one is doing it.


This guy here sells optical keys.

http://www.morseexpress.com/ghd/

Brian GM4DIJ


That's very interesting, Brian. I'd like to know more about his
technology, but at $429.95 I'm not in a hurry to buy a bug.

--
==================
Remove the "x" from my email address
Jerry, AI0K

==================

rickman wrote:

Roger Hayter wrote on 11/18/2017 4:04 PM:
Stephen Thomas Cole wrote:



Gents, can you please **** off.

If you have nothing to contribute to the discussion why join in at all?

My personal theory as to why few commercial morse keys use reed switches
or optical switches is that that users like to able to connect their
morse keys to a wide range of voltages and impedances, especially if you
include traditional valve equipment. Both technologies are intolerant
of excessive voltages or current compared with a pair of solid metal
contacts. I don't think either speed, latency or debouncing are
significant factors or, at least, they could be designed out.

Not trying to be argumentative, but I'd like to understand the basis of your
point. Why would the three things above not be factors in using mechanical
switches in keys? Bouncing switch contacts do pose an issue for clean
keying of a transmitter, no? So the bouncing has to be smoothed out. That
means adding electronics which means interface specific again, no? I
supposed you could use a high voltage capacitor and no buffer. That would
be a simple RC with the R in series with the key to the controlled point.

But the debouncing is likely to be in the keyed equipment rather than
the key.

By the way, i meant jitter[1], latency and that debouncing was no more
significant than for mechanical switches. So I expressed myself rather
inaccurately.





Maybe I'm not grasping what you are saying. How do you see a simple
mechanical switch being used to control many types of equipment?

BTW, there are transistors available that will switch high voltages and
currents. So a simple interface circuit would serve for use with many types
of equipment and any type of key switch you wish to use.

[1] Not speed which is about the same as latency, but jitter due to the
analogue stimulus triggering switching at a variable point as someone
pointed out at above.

--

Roger Hayter