[K3] Wetting current and CW paddles
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Hi,
i found this very interesting article by Hjalmar, OZ1JHM. http://www.oz1jhm.dk/content/wetting-current-and-cw-paddles With my Elecraft transceivers I have measured the following values: K3: 4.97 V, 0.105 mA -> 0.52 mW, 47.3 Ohm K2: 5.62 V, 0.670 mA -> 3.70 mW, 8.5 Ohm It seems that the effect described by Hjalmar would also apply to my K3. Does anyone have any insights into this? Is there already a modification for the K3 to increase the keyer current? Especially with fast CW speeds and the associated short contact times, the problem may already be known with some OM's. In any case, Hjalmar's article is very interesting and invites to observe the described effect. 73, Wolfgang DL2KI -- Sent from: http://elecraft.365791.n2.nabble.com/ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to lists+1215531472858-365791@n2.nabble.com |
Re: [K3] Wetting current and CW paddles
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On 2020-10-13 00:54:-0700, dl2ki wrote:
>Hi, >i found this very interesting article by Hjalmar, OZ1JHM http://www.oz1jhm.dk/content/wetting-current-and-cw-paddles I have an amusing story along these lines. Coming home one night from a late date with my wife, we came upon a car stalled at a light. It was perhaps 22-2300. I got out to see what I might do. The car would not start. The usual clicking from the starter, usually indicating a dead battery. Short version. I asked the other driver to turn on the radio. It worked. I then asked them to turn the headlamps. They worked. After a bit of additional troubleshooting, during which I did nothing to the car, I suggested they turn on the headlamps and attempt to start the car. It started. Arriving home, my wife promptly challenged me, saying that common practice is to turn off all electrics to preserve battery charge, and then attempt to start the car. I told her that the battery was fine, and I opined as time passed that there was possibly too much corrosion on the terminals. When the starter circuit engaged, it didn't draw enough current to move the solenoid fully. By turning on the headlamps, which are a large resistive load, a current path was generated through the oxidation. Then the starter was able to draw enough current to fully engage the solenoid. Of course, this may have been a fortunate coincidence. ;-) ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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Very informative , important info
Thanks 73 Andy HB9CVQ -----Original Message----- From: [hidden email] <[hidden email]> On Behalf Of Rich NE1EE Sent: Dienstag, 13. Oktober 2020 13:08 To: [hidden email] Subject: Re: [Elecraft] [K3] Wetting current and CW paddles On 2020-10-13 00:54:-0700, dl2ki wrote: >Hi, >i found this very interesting article by Hjalmar, OZ1JHM http://www.oz1jhm.dk/content/wetting-current-and-cw-paddles I have an amusing story along these lines. Coming home one night from a late date with my wife, we came upon a car stalled at a light. It was perhaps 22-2300. I got out to see what I might do. The car would not start. The usual clicking from the starter, usually indicating a dead battery. Short version. I asked the other driver to turn on the radio. It worked. I then asked them to turn the headlamps. They worked. After a bit of additional troubleshooting, during which I did nothing to the car, I suggested they turn on the headlamps and attempt to start the car. It started. Arriving home, my wife promptly challenged me, saying that common practice is to turn off all electrics to preserve battery charge, and then attempt to start the car. I told her that the battery was fine, and I opined as time passed that there was possibly too much corrosion on the terminals. When the starter circuit engaged, it didn't draw enough current to move the solenoid fully. By turning on the headlamps, which are a large resistive load, a current path was generated through the oxidation. Then the starter was able to draw enough current to fully engage the solenoid. Of course, this may have been a fortunate coincidence. ;-) ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Wetting current and CW paddles
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In reply to this post by Rich NE1EE
I, too, live in NH. We still get super cold periods, despite the general warming trend. My impression, stemming from growing up here in the 50s, and comparing to current weather, is that we are developing some unusual (for us) patterns. We have hotter summers and higher humidity, but less actual rain, resulting in the contradiction of sweltering summers accompanied by drought. Winters are milder, temperature-wise, but there is more precip over the winter months, much of it rain, and we now have longer periods of sub-0F weather...or so my heating bill seems to suggest. Ironically, we are faced with spring floods and summer droughts.
There is another alternative that I am considering that has its parallel in keyers. I am considering installing super caps. The difference is that I'd install the caps to provide an initial starter punch on those super cold days, whereas I'd install the caps on my keys to punch through oxide layers. The effect derives from the same source: the ability of the cap to provide a pulse of current in a short time. On 2020-10-13 07:21:-0400, Michael Stone wrote: >Back in the old days when the weather was colder than it is now, I was living in New Hampshire. I didn’t have a garage for my car. There is a trick that someone told me about that apparently works when you know that the vehicle might not turn over fast enough and start on a below zero morning. Turn the headlights on for several seconds to less than a minute to create a bit of heat in the battery that in turns gets the chemical reaction going. This sometimes helps�or appears to help. My choice of insuring that the engine started was to remove the battery and bring it into the house and then reinstall it just before starting the engine. Lots of extra work, but I was never late for work due to cold weather. >Mike, N1VE ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by dl2ki
Hi,
actually I expected a little discussion on a qualified professional level in this mailing list. Otherwise I would not ask here. But the topic does not seem to invite to it. 73, Wolfgang DL2KI -- Sent from: http://elecraft.365791.n2.nabble.com/ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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Not a professional here but I think it's a very interesting topic and
wonder if it applies to manual keys as well. A typical solution for semi-automatic "bugs" (probably mis-adjusted) is to place a capacitor across the terminals to alleviate "scratchiness". I have an old Bunnell Double Speed "cootie" key that, if the contact spacing is adjusted too wide, will produce erratic contact bounce keying on the K3. I've never thought what effect a resistor across the terminals might have. FWIW, regarding wetting current-- we used to have DSL internet over telephone lines at my house, which the provider was not interested in maintaining, trying to push subscribers to fiber. The lines were allowed to deteriorate badly for a couple of years before copper was finally retired. During this time I solved the noise and low DSL speeds very successfully by placing a suitable size resistor across the line-- the constant current through oxidized connections & corroded terminals kept the noise at bay. As I recall, a 15ma "sealing" current was enough to keep it noise free but not enough to off-hook the line. 73, Drew AF2Z On 10/15/20 02:23, dl2ki wrote: > Hi, > > actually I expected a little discussion on a qualified professional level in > this mailing list. Otherwise I would not ask here. But the topic does not > seem to invite to it. > > > 73, Wolfgang > DL2KI > > > > -- > Sent from: http://elecraft.365791.n2.nabble.com/ > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Wetting current and CW paddles
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In reply to this post by dl2ki
Hi Wolfgang,
A DC wetting current has been common in relay circuits that would otherwise just be switching low level alternating current signals. I recall seeing it applied to RX front end filter switching relays. Regards, Mike VP8NO (G3VUI) On 15/10/2020 04:23, dl2ki wrote: > Hi, > > actually I expected a little discussion on a qualified professional level in > this mailing list. Otherwise I would not ask here. But the topic does not > seem to invite to it. > > > 73, Wolfgang > DL2KI ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Wetting current and CW paddles
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In radio & TV broadcasting we used "Dry" contacts for microphone switching.
Both relays and switches. The contacts actually wiped a tiny amount as they made or broke. Usually the contacts were actually gold plated stiff wires that were mounted at a right angle. 73 George AI4VZ A DC wetting current has been common in relay circuits that would > otherwise just be switching low level alternating current signals. I > recall seeing it applied to RX front end filter switching relays. > > Regards, > > Mike VP8NO (G3VUI) > > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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In reply to this post by dl2ki
Hi,
i posted the article here for discussion, because I can't judge it myself. I think that Elecraft had a little idea to design the keyer electronics of the K3 as it is. Interesting is the difference to the K2, where the resistors R1 and R2 were changed in revision "B". Again I can't judge if this had anything to do with this topic. OK, I'll just leave it like this. Maybe somebody will have some experience with it after all. Thanks a lot Wolfgang, DL2KI -- Sent from: http://elecraft.365791.n2.nabble.com/ ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Wetting current and CW paddles
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Sliding off topic a little: in designing some outdoor industrial control equipment I was required to use some chunky, robust push buttons that were good for high voltage, high current but no good at 12V. Getting to logic level I had to build in a lot of extra current from 12V to ensure a good switch over, I think some 30mA or so.
Using a favourite pre-war Morse key on vintage valve gear, it worked perfectly, but on modern solid state equipment it was very intermittent and I didn't want to make an interface. Solution, clean the contacts. Conclusion: modern gear needs better contacts than the old stuff. David G3UNA/G6CP > On 15 October 2020 at 15:19 dl2ki <[hidden email] mailto:[hidden email] > wrote: > > > Hi, > > i posted the article here for discussion, because I can't judge it myself. > > I think that Elecraft had a little idea to design the keyer electronics of > the K3 as it is. > > Interesting is the difference to the K2, where the resistors R1 and R2 were > changed in revision "B". Again I can't judge if this had anything to do with > this topic. > > OK, I'll just leave it like this. Maybe somebody will have some experience > with it after all. > > Thanks a lot > Wolfgang, DL2KI > > > > > -- > Sent from: http://elecraft.365791.n2.nabble.com/ > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] mailto:[hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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I think there could be more than just clean contacts involved. As I
mentioned, on my old cootie style key, whose contacts have a mirror finish, when the contact gap is set too wide the keying will be erratic on the K3; no doubt due to my particular sending style combined with the relatively "hard" action of the key. When a smaller contact gap is used the keying is fine. I have no idea how key contact de-bouncing is accomplished in modern rigs. I assume there is some coding in the software in addition to whatever electronic components are used. I am wondering if it would be worthwhile for a modern rig (K4?) to make the parameters in the debounce routine available as a user option in the software so it could be tailored to individual keys... 73, Drew AF2Z On 10/15/20 10:04, CUTTER DAVID via Elecraft wrote: > Sliding off topic a little: in designing some outdoor industrial control equipment I was required to use some chunky, robust push buttons that were good for high voltage, high current but no good at 12V. Getting to logic level I had to build in a lot of extra current from 12V to ensure a good switch over, I think some 30mA or so. > > Using a favourite pre-war Morse key on vintage valve gear, it worked perfectly, but on modern solid state equipment it was very intermittent and I didn't want to make an interface. Solution, clean the contacts. Conclusion: modern gear needs better contacts than the old stuff. > > David G3UNA/G6CP > >> On 15 October 2020 at 15:19 dl2ki <[hidden email] mailto:[hidden email] > wrote: >> >> >> Hi, >> >> i posted the article here for discussion, because I can't judge it myself. >> >> I think that Elecraft had a little idea to design the keyer electronics of >> the K3 as it is. >> >> Interesting is the difference to the K2, where the resistors R1 and R2 were >> changed in revision "B". Again I can't judge if this had anything to do with >> this topic. >> >> OK, I'll just leave it like this. Maybe somebody will have some experience >> with it after all. >> >> Thanks a lot >> Wolfgang, DL2KI >> >> >> >> >> -- >> Sent from: http://elecraft.365791.n2.nabble.com/ >> ______________________________________________________________ >> Elecraft mailing list >> Home: http://mailman.qth.net/mailman/listinfo/elecraft >> Help: http://mailman.qth.net/mmfaq.htm >> Post: mailto:[hidden email] mailto:[hidden email] >> >> This list hosted by: http://www.qsl.net >> Please help support this email list: http://www.qsl.net/donate.html >> Message delivered to [hidden email] mailto:[hidden email] >> > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] > Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Wetting current and CW paddles
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On 2020-10-15 11:51:-0400, Drew AF2Z wrote:
>I think there could be more than just clean contacts involved. I suspect from my own undocumented tinkering that contact geometry is also involved. Back in the day when currents were higher, we'd burnish contacts to flat, parallel surfaces. The instruments and controls that I have in mind were routinely serviced. They were routinely serviced because contact were observed in DC control systems transferring metal from one contact to the other, resulting in a pit on one side and a peak on the other. Perhaps modern key contacts can benefit from at least one of the contacts coming more to a point. This would increase contact pressure due to the reduced contact area, and would result in higher charge density near the tip, and therefore higher potentials as the contacts closed. Two factors: tip radius (smaller is better) and tip contact area (more is better). I have found for some keys with metals that corroded more quickly that periodic light cleaning is all that is required, but for those keys with less active metals, reshaping worked well to reduce false contact closures. I still stutter on some occasions on all my keys. ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Wetting current and CW paddles
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In reply to this post by Elecraft mailing list
When I built a single level paddle, I decided to use silver for
the contacts after hearing that all the corrosion products of silver were conductive. I soldered two short pieces of silver wire, contributed by a jewelry maker in the family, at right angles to each other on the contact bases. In spite of mostly sitting on the shelf for five or so years, presumably corroding, this system still works quite reliably. I have recently been using it with a Rockmite, and it shows no signs of intermittency. 73 Bill AE6JV On 10/15/20 at 11:04 AM, [hidden email] (CUTTER DAVID via Elecraft) wrote: >Using a favourite pre-war Morse key on vintage valve gear, it >worked perfectly, but on modern solid state equipment it was >very intermittent and I didn't want to make an interface. >Solution, clean the contacts. Conclusion: modern gear needs >better contacts than the old stuff. --------------------------------------------------------------------------- Bill Frantz |"We used to quip that "password" is the most common 408-348-7900 | password. Now it's 'password1.' Who said users haven't www.pwpconsult.com | learned anything about security?" -- Bruce Schneier ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Wetting current and CW paddles
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Another solution is to use hermetically-sealed contacts. I built a
light-weight, single-lever key paddle using microswitches for the contacts. It worked very well and never had problems with scratchy contacts. http://n1al.net/ham/paddle.htm Alan N1AL On 10/15/2020 11:42 AM, Bill Frantz wrote: > When I built a single level paddle, I decided to use silver for the > contacts ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: [K3] Wetting current and CW paddles
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Very cool looking key! Clean lines, no clutter.
On 2020-10-15 12:24:-0600, Alan Bloom wrote: >Another solution is to use hermetically-sealed contacts.� I built a light-weight, single-lever key paddle using microswitches for the contacts.� It worked very well and never had problems with scratchy contacts. > >http://n1al.net/ham/paddle.htm > >Alan N1AL ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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