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#51
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Morse Key Contacts?
Roger Hayter wrote on 11/18/2017 7:59 PM:
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. Is it? When you talk about working with a multitude of equipment, I would doubt that is always true. 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. My point is that no one has explained why there would be an more jitter/latency or whatever with a reed switch than with the sort of mechanical switch made home brew. In fact, reed switches have very short debounce and latency times. In at least one spec sheet I found they use a number which is a fraction of a millisecond. 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. I have seen no reasonable explanation of how a reed switch is any more analog than a mechanical switch. They are both analog movements of a mechanism. The only difference is one adjusts a magnetic field while the other applies pressure to a spring which bends (again in an analog manner) until it begins to make contact with another spring. Which will have more jitter? Only a measurement will say and the reed switch has a much lower time of bouncing, so will not possibly have a noticeable jitter in time of actuation. -- Rick C Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998 |
#52
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Morse Key Contacts?
Jerry Stuckle wrote on 11/18/2017 5:50 PM:
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? There are magnetic hall effect switches around. 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. 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). 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. It "puddles" as the contacts are pulled apart due to surface tension. It leads to irregular break timing. 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. What is the timing precision requirement for CW? Does optical satisfy it? Never tried optical but as long as you can get a clean make/break of the beam it should work. The problem as i see it would be that clean make/break; the beam will fade in and out. 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. And even if they get pitted they are soft enough to burnish rather easily and thick enough to last for years. So no numbers? 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". 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. So I'm not sure what "clean" make/break means. 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. However, reed switches operate via a magnetic field. 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. 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? 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. That is the context in which they were brought up. 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. How about you address the issues rather than diverting the discussion. I'm not diverting the discussion. You just don't understand how magnetic and optical sensors work. That is very obvious. Go back and read. 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. Jerry, I'm not going to continue to debate pointless issues with you. What you are doing here is off-topic. I'm done with it. Reed switches are *not* analog any more than mechanical switches in that they don't vary the connection continuously. They are still metallic switches and make or break when the metals touch. 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". I found no information indicating significant variations in the action of reed switches. The variation in pull-in and release field strength gives a small amount of hysteresis which is desirable in any switch. 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. 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. All analog until the switch pieces make contact which results in a discrete output change. The real difference is in the bounce time. A mercury wetted reed switch has no bounce time, contact is singular and certain. A mechanical switch has a variable resistance until the point of contact stops moving and settles down. That's the bounce time. I did tell you the difference. But you called it off-topic. This is not related to bounce time. But you can't get over that fact. And you have failed to explain what *is* the problem. Rather than discuss the issue you are diverting. 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. You've explained nothing. You simply claim that a magnetic sensor is somehow more analog than a mechanical sensor which is not really true. They both have an analog part that is converted to a digital signal. No explanation, just a claim. Likewise optical is only optical in the movement of the paddle and the signal seen by the detector. Once the signal passes through a threshold detector with hysteresis the signal is purely digital. 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. It is easy enough to exclude ambient light. And how are you going to do that without restricting the motion of the paddles? Oh, I know. 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. I guess you've never used a camera with a mechanical shutter? 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. Only when the shutter *allows* the light to enter which is a few milliseconds at a time and the rest of the time the film receives so little light it can sit there for months without the film becoming exposed. Are you really going to argue that you can't see how to keep the light out of a sensor if you want to? 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. 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. 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. Compensating for the uncertainly can't be done. So what is the problem in mechanical switches if not bounce? 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! 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. You are a trip. You actually have no interest in discussing the topic. Your analysis above shows a complete lack of understanding of how switches in general work and not just reed switches. Try reading about switches a bit. You will quickly find that metallic switches do not make or break cleanly with an "instantaneous" connection. Just use google or any other tool to find some info on this and read it. Nope, my analysis is right on. And it is exactly why reed and optical switching is not used in keys and paddles. You actually haven't analyzed anything. 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. 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. 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. 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? 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. 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? 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. I'm done with this. You make up all sorts of crap rather than just discuss a topic. Do it with someone else. -- Rick C Viewed the eclipse at Wintercrest Farms, on the centerline of totality since 1998 |
#53
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Morse Key Contacts?
On 11/18/2017 9:51 PM, rickman wrote:
Jerry Stuckle wrote on 11/18/2017 5:50 PM: 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.Â* That means going off-topic. Â*Nothing of the sort. Jerry, I'm not going to continue to debate pointless issues with you. What you are doing here is off-topic.Â* I'm done with it. That's just like you. Rather than admit you know nothing about the subject, you claim it's off-topic and then you won't discuss it. 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.Â* But you're so full of yourself that you can't understand the topic.Â* But that's your style. You've explained nothing.Â* You simply claim that a magnetic sensor is somehow more analog than a mechanical sensor which is not really true. They both have an analog part that is converted to a digital signal.Â* No explanation, just a claim. I have explained it thoroughly. It's not my fault if you can't understand simple technical issues. I would expect that from anyone who had completed their sophomore year in an EE program. You've once again proven your claim of having an MSEE is bull****. 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?Â* You haven't explained how to keep the light out without restricting the paddle.Â* Not that I expect you were able to do so. Only when the shutter *allows* the light to enter which is a few milliseconds at a time and the rest of the time the film receives so little light it can sit there for months without the film becoming exposed. Are you really going to argue that you can't see how to keep the light out of a sensor if you want to? What's the matter? You can't show how it can be done so you try to say I'm arguing? ROFLMAO! Once again you show your stoopidity. I challenged you to show how you can do it. But you can't, so end of topic. 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.Â* Nothing of the sort.Â* Debounce circuits are for a different problem. And I have explained the issue.Â* You are just too full of yourself to try to understand it.Â* But that's what I expect from you, Rick. You are a trip.Â* You actually have no interest in discussing the topic. Yes, you are a trip. You can't discuss the topic because you have no clue. Unlike you, I have been discussing the topic. But it takes a modicum of technical knowledge, which means it is way over your head - as usual. 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.Â* Nothing of the sort.Â* And no, I did NOT say the magnetic switch was analog.Â* 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.Â* You can't even show one commercial key which does.Â* 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.Â* Over 700K hams in the United States alone.Â* If even 10% of them buy one of your paddles at $100 each, that's over $7 Million.Â* And if it's that good I would expect at least that percentage to buy them. But I know you won't.Â* 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).Â* Even someone with a two year technical degree understands the problems. But this is normal for you, Rick.Â* Go ahead and make a fool of yourself. Â*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. I'm done with this.Â* You make up all sorts of crap rather than just discuss a topic.Â* Do it with someone else. This is more of the Rick style. You get into a topic that you know nothing about, but rather than try to learn you say it's off topic and I'm arguing. But all you're doing is continuing to make a fool of yourself and proving your claim of an MSEE is complete bull****. -- ================== Remove the "x" from my email address Jerry, AI0K ================== |
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Morse Key Contacts?
Jerry Stuckle wrote:
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. Reported to ISP for off-topic posting. -- STC / M0TEY / http://twitter.com/ukradioamateur |
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Morse Key Contacts?
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? One minute it's ok to have a joke on Usenet, the next it isn't. Make up your mind, Rog! Your inconsistency is making you look vindictive, OM. -- STC / M0TEY / http://twitter.com/ukradioamateur |
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Morse Key Contacts?
One minute it's ok to have a joke on Usenet, the next it isn't. Make up your mind, Rog! Your inconsistency is making you look vindictive, OM. ask brian reay...he doesn't like jokes ...... |
#57
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Morse Key Contacts?
"Brian Howie" wrote in message ... 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 here is a nice key for sale ... https://www.ebay.co.uk/itm/282739246...84.m1555.l2649 |
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Morse Key Contacts?
On 18/11/2017 22:02, 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.Â*Â* Both technologies are intolerant of excessive voltages or current compared with a pair of solid metal contacts.Â* 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.Â* Why would the three things above not be factors in using mechanical switches in keys?Â* Bouncing switch contacts do pose an issue for clean keying of a transmitter, no?Â* So the bouncing has to be smoothed out. But you also need to remove the fast switching 'edges', the circuitry which does this will also remove the 'bounce' effects found in a mechanical switch. From a practical view point, worrying about 'fast' switching at the Morse Key seems rather nugatory when you need to ensure the transmitter isn't actually 'keyed' so 'fast' that key clicks are generated (with their attendant problems). As to why Morse keys haven't been 'modernised' - perhaps it is as simple as users like the traditional approach. I still prefer a mechanical wrist watch. -- Suspect someone is claiming a benefit under false pretences? Incapacity Benefit or Personal Independence Payment when they don't need it? They are depriving those in real need! https://www.gov.uk/report-benefit-fraud |
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Morse Key Contacts?
As to why Morse keys haven't been 'modernised' - perhaps it is as simple as users like the traditional approach. I still prefer a mechanical wrist watch. me too...and my nokia 1100 .......and my IC728'S.....and a nice big RWD Mustang ......and chain driven cams...and LW ........etc |
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Morse Key Contacts?
rickman wrote:
snip I have seen no reasonable explanation of how a reed switch is any more analog than a mechanical switch. They are both analog movements of a mechanism. The only difference is one adjusts a magnetic field while the other applies pressure to a spring which bends (again in an analog manner) until it begins to make contact with another spring. Which will have more jitter? Only a measurement will say and the reed switch has a much lower time of bouncing, so will not possibly have a noticeable jitter in time of actuation. I agree that jitter is not a major issue, but I do think that with a mechanical switch that human muscles and brain are directly part of the analogue feedback loop controlling jitter in a way they may not be with an intervening magnetic link. At least with a straight key, if springs are part ot the system then your argument is more convincing. This is a different issue from contact bounce, which occurs after the initial contact closure. -- Roger Hayter |
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