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I have a resistive surface that has been used for a paddle… ? But.? ? It isn’t a specific resistance.? It is open when not being touched.? When touched it changes with the amount of pressure.? At a very light pressure it might be 50K.? with high pressure it is just 1K. ? Doesn’t seem to me this is the sort of thing that would meet the need.? What is needed is a surface that has a fixed resistance that can be fed a little power and warm and in itself have nothing to do with the keying. ? The paddle already has ground on it, so it would call for one additional wire for a plus power source.? It would need to warm, not be hot, at say five volts, and ideally, not consume a lot of power.? Would seem a fraction of a watt would be adequate. ? If there exists a highly resistive wire I can imagine imbedding it in something that can handle a little warmth and make it into a paddle surface. ? Any ideas being stimulated? ? fd
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Maybe nichrome 60 or80? ?Or Kapton film elements?
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On Jan 4, 2025, at 15:42, Fred Maas via groups.io <just.one.hill@...> wrote:
? I have a resistive surface that has been used for a paddle… ? But.? ? It isn’t a specific resistance.? It is open when not being touched.? When touched it changes with the amount of pressure.? At a very light pressure it might be 50K.? with high pressure it is just 1K. ? Doesn’t seem to me this is the sort of thing that would meet the need.? What is needed is a surface that has a fixed resistance that can be fed a little power and warm and in itself have nothing to do with the keying. ? The paddle already has ground on it, so it would call for one additional wire for a plus power source.? It would need to warm, not be hot, at say five volts, and ideally, not consume a lot of power.? Would seem a fraction of a watt would be adequate. ? If there exists a highly resistive wire I can imagine imbedding it in something that can handle a little warmth and make it into a paddle surface. ? Any ideas being stimulated? ? fd
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Wonder how much resistance an inch of it might have? ? ? ?
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From: [email protected] <[email protected]> On Behalf Of Tom Armer via groups.io
Sent: Saturday, January 4, 2025 6:28 PM
To: [email protected]
Subject: Re: [W5N-SOTA] heated paddle? Maybe nichrome 60 or80? ?Or Kapton film elements? ? I have a resistive surface that has been used for a paddle… ? But.? ? It isn’t a specific resistance.? It is open when not being touched.? When touched it changes with the amount of pressure.? At a very light pressure it might be 50K.? with high pressure it is just 1K. ? Doesn’t seem to me this is the sort of thing that would meet the need.? What is needed is a surface that has a fixed resistance that can be fed a little power and warm and in itself have nothing to do with the keying. ? The paddle already has ground on it, so it would call for one additional wire for a plus power source.? It would need to warm, not be hot, at say five volts, and ideally, not consume a lot of power.? Would seem a fraction of a watt would be adequate. ? If there exists a highly resistive wire I can imagine imbedding it in something that can handle a little warmth and make it into a paddle surface. ? Any ideas being stimulated? ? fd
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What is the material to be heated? What is its mass. What would be the ambient temp? ?From that I can calculate Watts required for a desired temp rise above ambient. ?
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On Jan 4, 2025, at 18:31, Fred Maas via groups.io <just.one.hill@...> wrote:
? Wonder how much resistance an inch of it might have? ? ? ? ? Maybe nichrome 60 or80? ?Or Kapton film elements? ? I have a resistive surface that has been used for a paddle… ? But.? ? It isn’t a specific resistance.? It is open when not being touched.? When touched it changes with the amount of pressure.? At a very light pressure it might be 50K.? with high pressure it is just 1K. ? Doesn’t seem to me this is the sort of thing that would meet the need.? What is needed is a surface that has a fixed resistance that can be fed a little power and warm and in itself have nothing to do with the keying. ? The paddle already has ground on it, so it would call for one additional wire for a plus power source.? It would need to warm, not be hot, at say five volts, and ideally, not consume a lot of power.? Would seem a fraction of a watt would be adequate. ? If there exists a highly resistive wire I can imagine imbedding it in something that can handle a little warmth and make it into a paddle surface. ? Any ideas being stimulated? ? fd
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What is the material to be heated? What is its mass. What would be the ambient temp? ?From that I can calculate Watts required for a desired temp rise above ambient. ? K6TAA? ? That’s an interesting step…? talking about less than a square inch paddle surface, maybe even half that.? Ambient is wide ranging, call it 20F.? If it could raise the temperature of the surface by perhaps 20 degrees, that would be right in there.? I don’t know what the material might be.? Wire or resistance could be sandwiched between layers of something, plastic perhaps?? Or imbedded in a bit of colorful epoxy? ? ?
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On Jan 4, 2025, at 18:31, Fred Maas via groups.io <just.one.hill@...> wrote:
? Wonder how much resistance an inch of it might have? ? ? ? ? Maybe nichrome 60 or80? ?Or Kapton film elements? ? I have a resistive surface that has been used for a paddle… ? But.? ? It isn’t a specific resistance.? It is open when not being touched.? When touched it changes with the amount of pressure.? At a very light pressure it might be 50K.? with high pressure it is just 1K. ? Doesn’t seem to me this is the sort of thing that would meet the need.? What is needed is a surface that has a fixed resistance that can be fed a little power and warm and in itself have nothing to do with the keying. ? The paddle already has ground on it, so it would call for one additional wire for a plus power source.? It would need to warm, not be hot, at say five volts, and ideally, not consume a lot of power.? Would seem a fraction of a watt would be adequate. ? If there exists a highly resistive wire I can imagine imbedding it in something that can handle a little warmth and make it into a paddle surface. ? Any ideas being stimulated? ? fd
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There are heated garments for motorcycling and snow mobiling. ?Deb has used that a lot on her long distance rides. ? I currently have a pair of gloves and a vest that I wear on the tractor when snow plowing. ?That stuff really works! ??
My other go to game changer for hunting particularly holding up cold binoculars ?for hours and hours are the chemical hand warmers called hot hands. ?
I also remember Mike built a pair of cw gloves that worked for him! -Dave
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On Jan 4, 2025, at 18:44, Fred Maas via groups.io <just.one.hill@...> wrote:
? What is the material to be heated? What is its mass. What would be the ambient temp? ?From that I can calculate Watts required for a desired temp rise above ambient. ? K6TAA? ? That’s an interesting step…? talking about less than a square inch paddle surface, maybe even half that.? Ambient is wide ranging, call it 20F.? If it could raise the temperature of the surface by perhaps 20 degrees, that would be right in there.? I don’t know what the material might be.? Wire or resistance could be sandwiched between layers of something, plastic perhaps?? Or imbedded in a bit of colorful epoxy? ? ? ? Wonder how much resistance an inch of it might have? ? ? ? ? Maybe nichrome 60 or80? ?Or Kapton film elements? ? I have a resistive surface that has been used for a paddle… ? But.? ? It isn’t a specific resistance.? It is open when not being touched.? When touched it changes with the amount of pressure.? At a very light pressure it might be 50K.? with high pressure it is just 1K. ? Doesn’t seem to me this is the sort of thing that would meet the need.? What is needed is a surface that has a fixed resistance that can be fed a little power and warm and in itself have nothing to do with the keying. ? The paddle already has ground on it, so it would call for one additional wire for a plus power source.? It would need to warm, not be hot, at say five volts, and ideally, not consume a lot of power.? Would seem a fraction of a watt would be adequate. ? If there exists a highly resistive wire I can imagine imbedding it in something that can handle a little warmth and make it into a paddle surface. ? Any ideas being stimulated? ? fd
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Yea, CW in the winter can be a real problem - unlike phone where dexterity really isn't necessary. For a few years I activated from the Crest on New Year's Eve at the Zulu year crossover. It was a lot of fun but my hands got so cold/numb I had to occasionally suspend and sit in the car for awhile with the heat on to get some feeling back.??
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Here's a video of the clipboard/gloved setup Dave mentioned. I've used it a number of times in cold weather with the medium gloves shown. The thick gloves are much warmer and I can send pretty well with them - the problem is that I can't write with them! :-) Anyone who's tried to do anything that requires dexterity with thick gloves like that will know what I mean.?
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Not sure what's happened lately with electrically heated gloves but I suspect there are now lightweight versions using some sort of rechargeable lithium batteries that might be workable.? As Dave says "hot hands" work pretty well.
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Back when I used to ride motorcycles a lot I had a Widder electrical vest/gloves setup that attached to the bike's battery and worked great. My first ride with these was ... magic! Suddenly the cold didn't matter. I could ride all year round.?
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Seems to me that heating the paddles themselves wouldn't make a lot of difference. The small area involved wouldn't really keep your hands from getting numb.
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73, Mike - ke5akl
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Fred, I have several meters of Nichrome 60 and Nichrome 80; 28 and 18 gauge. Can send up, or bring to you.? ?Did some estimates- looks like you will need 2 watts to warm paddles 25-40F above ambient. That would take about 8 cm of wire at 1.5V at a max discharge of 1.5-2 amps. ?Could refine estimate with more detailed data about the key, ?but the ?estimate shows it might be feasible-experimental verification on a surrogate set of paddles would be mandatory before assembling.?
That much wire could be wound into a 1-5 -2 cm dia circular spiral or 1.5-2cm wide square spiral that would lay on back of paddles held by epoxy or Silicone RTV. ?Would probably want a potentiometer in there to adjust power to wire.?
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On Jan 4, 2025, at 19:27, David Fuller via groups.io <nn5k@...> wrote:
? There are heated garments for motorcycling and snow mobiling. ?Deb has used that a lot on her long distance rides. ? I currently have a pair of gloves and a vest that I wear on the tractor when snow plowing. ?That stuff really works! ??
My other go to game changer for hunting particularly holding up cold binoculars ?for hours and hours are the chemical hand warmers called hot hands. ?
I also remember Mike built a pair of cw gloves that worked for him! -Dave On Jan 4, 2025, at 18:44, Fred Maas via groups.io <just.one.hill@...> wrote:
? What is the material to be heated? What is its mass. What would be the ambient temp? ?From that I can calculate Watts required for a desired temp rise above ambient. ? K6TAA? ? That’s an interesting step…? talking about less than a square inch paddle surface, maybe even half that.? Ambient is wide ranging, call it 20F.? If it could raise the temperature of the surface by perhaps 20 degrees, that would be right in there.? I don’t know what the material might be.? Wire or resistance could be sandwiched between layers of something, plastic perhaps?? Or imbedded in a bit of colorful epoxy? ? ? ? Wonder how much resistance an inch of it might have? ? ? ? ? Maybe nichrome 60 or80? ?Or Kapton film elements? ? I have a resistive surface that has been used for a paddle… ? But.? ? It isn’t a specific resistance.? It is open when not being touched.? When touched it changes with the amount of pressure.? At a very light pressure it might be 50K.? with high pressure it is just 1K. ? Doesn’t seem to me this is the sort of thing that would meet the need.? What is needed is a surface that has a fixed resistance that can be fed a little power and warm and in itself have nothing to do with the keying. ? The paddle already has ground on it, so it would call for one additional wire for a plus power source.? It would need to warm, not be hot, at say five volts, and ideally, not consume a lot of power.? Would seem a fraction of a watt would be adequate. ? If there exists a highly resistive wire I can imagine imbedding it in something that can handle a little warmth and make it into a paddle surface. ? Any ideas being stimulated? ? fd
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Wow, Tom, your calculations are very telling.? Thank you for taking the time to do it. ? Remember there are two surfaces to be heated.? What your calculations indicate is that much too much current is needed to significantly warm for this to be feasible using borrowed power from these little radios. ? !!!? fred ? Fred, I have several meters of Nichrome 60 and Nichrome 80; 28 and 18 gauge. Can send up, or bring to you.? ? ?Did some estimates- looks like you will need 2 watts to warm paddles 25-40F above ambient. That would take about 8 cm of wire at 1.5V at a max discharge of 1.5-2 amps. ?Could refine estimate with more detailed data about the key, ?but the ?estimate shows it might be feasible-experimental verification on a surrogate set of paddles would be mandatory before assembling.? That much wire could be wound into a 1-5 -2 cm dia circular spiral or 1.5-2cm wide square spiral that would lay on back of paddles held by epoxy or Silicone RTV. ?Would probably want a potentiometer in there to adjust power to wire.?
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I also have a pair heated gloves, they run off of C cells. When my hands are warm to start, I can tolerate cold fingers pretty well for the duration of a CW activation unless it’s very windy. That said, heated paddle finger pieces would be a neat trick!
73, John?
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On Jan 5, 2025, at 5:22?PM, Fred Maas via groups.io <just.one.hill@...> wrote:
? Wow, Tom, your calculations are very telling.? Thank you for taking the time to do it. ? Remember there are two surfaces to be heated.? What your calculations indicate is that much too much current is needed to significantly warm for this to be feasible using borrowed power from these little radios. ? !!!? fred ? Fred, I have several meters of Nichrome 60 and Nichrome 80; 28 and 18 gauge. Can send up, or bring to you.? ? ?Did some estimates- looks like you will need 2 watts to warm paddles 25-40F above ambient. That would take about 8 cm of wire at 1.5V at a max discharge of 1.5-2 amps. ?Could refine estimate with more detailed data about the key, ?but the ?estimate shows it might be feasible-experimental verification on a surrogate set of paddles would be mandatory before assembling.? That much wire could be wound into a 1-5 -2 cm dia circular spiral or 1.5-2cm wide square spiral that would lay on back of paddles held by epoxy or Silicone RTV. ?Would probably want a potentiometer in there to adjust power to wire.?
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Fred- I assumed a mass of 5 grams with 6 square inches to be heated (2- paddles, 1.5 sq in per paddle side, 2 sides per paddle because heat is transferred off both open faces of the paddles). ?Assumed paddle's heat capacity and conductivity equivalent to Polyethylene. Assumed the temp rise required was 25F. ?The power draw would drain a AA LiIon 1.5 volt in about an hour. ?
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On Jan 5, 2025, at 16:41, John K1JD via groups.io <johnk1jd@...> wrote:
? I also have a pair heated gloves, they run off of C cells. When my hands are warm to start, I can tolerate cold fingers pretty well for the duration of a CW activation unless it’s very windy. That said, heated paddle finger pieces would be a neat trick!
73, John?
On Jan 5, 2025, at 5:22?PM, Fred Maas via groups.io <just.one.hill@...> wrote:
? Wow, Tom, your calculations are very telling.? Thank you for taking the time to do it. ? Remember there are two surfaces to be heated.? What your calculations indicate is that much too much current is needed to significantly warm for this to be feasible using borrowed power from these little radios. ? !!!? fred ? Fred, I have several meters of Nichrome 60 and Nichrome 80; 28 and 18 gauge. Can send up, or bring to you.? ? ?Did some estimates- looks like you will need 2 watts to warm paddles 25-40F above ambient. That would take about 8 cm of wire at 1.5V at a max discharge of 1.5-2 amps. ?Could refine estimate with more detailed data about the key, ?but the ?estimate shows it might be feasible-experimental verification on a surrogate set of paddles would be mandatory before assembling.? That much wire could be wound into a 1-5 -2 cm dia circular spiral or 1.5-2cm wide square spiral that would lay on back of paddles held by epoxy or Silicone RTV. ?Would probably want a potentiometer in there to adjust power to wire.?
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? Fred- I assumed a mass of 5 grams with 6 square inches to be heated (2- paddles, 1.5 sq in per paddle side, 2 sides per paddle because heat is transferred off both open faces of the paddles). ?Assumed paddle's heat capacity and conductivity equivalent to Polyethylene. Assumed the temp rise required was 25F. ?The power draw would drain a AA LiIon 1.5 volt in about an hour. ? ? <<<? Not even close to that kind of power could come from the little radios like the MTR or the KH1 by simply tapping into a 5 volt circuit… ? <<<? Personally, I wouldn’t want the ergonomics of a situation that I envision could be workable, but someone else might, especially someone who is not hiking particularly far. ? what I think could work is if one is using a clipboard for logging and to which is attached a paddle… and a mounting for a lithium battery.? This wouldn’t threaten any circuits in the radio.? The nichrome wire plus a dropping resistor or potentiometer as needed to get the desired wattage… something like this could work.? I don’t have a suitable paddle to play with the notion. ? fred
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Several of us in Colorado just climb in a Bothy bag when activating the high peaks, particularly in the shoulder seasons and winter when the temps drop below zero with blowing snow.? It's amazing how quickly you warm up and need to remove gloves and jackets!? The worse part is getting out of the bag after activating for an hour or two ;-).?
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HNY and 73, Brad
WA6MM
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John K1JD
Brad - WA6MM