Cold K3
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During the California QSO Party, the temperatures in our
operation tent dropped below freezing. Two of us felt that we were not getting full power out of our K3s when the internal temperatures were low. Given that we were using the K3 to measure power output, low temperatures could be affecting the measurement rather than the power. After sending CQ for 5 or 10 minutes, the K3s warmed up and the output power rose to normal. Too bad calling CQ didn't warm the operators as well. HIHI Since we were getting about 90% power with the internal temperatures at zero C, it is not a major issue, but we are curious. Has anyone else experienced this effect? 73 Bill AE6JV ----------------------------------------------------------------------- Bill Frantz | Concurrency is hard. 12 out | Periwinkle (408)356-8506 | 10 programmers get it wrong. | 16345 Englewood Ave www.pwpconsult.com | - Jeff Frantz | Los Gatos, CA 95032 ______________________________________________________________ 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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Hi Bill,
It is a characteristic of transistors. I have always been taught that they need to be biased down to about half their safe output to avoid thermal runaway. That was a long time ago. Things may have changed. As they heat up, they increase their amplification, as they amplify, they heat up, and so on. Cold temps works the opposite. In the early days of solid state mobile rigs, and during Minnesota winters, we could turn on our rigs and get nothing but maybe a back-light on the dial. After a few minutes, it would start to have sound coming out of the speaker, as the circuit and components warmed up. It also affects the oscillators. Dick, n0ce ________________________________ From: Elecraft <[hidden email]> on behalf of Bill Frantz <[hidden email]> Sent: Tuesday, October 4, 2016 12:14 AM To: [hidden email] Subject: [Elecraft] Cold K3 During the California QSO Party, the temperatures in our operation tent dropped below freezing. Two of us felt that we were not getting full power out of our K3s when the internal temperatures were low. Given that we were using the K3 to measure power output, low temperatures could be affecting the measurement rather than the power. After sending CQ for 5 or 10 minutes, the K3s warmed up and the output power rose to normal. Too bad calling CQ didn't warm the operators as well. HIHI Since we were getting about 90% power with the internal temperatures at zero C, it is not a major issue, but we are curious. Has anyone else experienced this effect? 73 Bill AE6JV ----------------------------------------------------------------------- Bill Frantz | Concurrency is hard. 12 out | Periwinkle (408)356-8506 | 10 programmers get it wrong. | 16345 Englewood Ave www.pwpconsult.com<http://www.pwpconsult.com> | - Jeff Frantz | Los Gatos, Periwinkle Computer Consulting - pwpconsult.com<http://www.pwpconsult.com/> www.pwpconsult.com Security Communications Quality Assurance Promoting Community Through Secure, Reliable Computing. Periwinkle is a husband and wife team with over ... CA 95032 ______________________________________________________________ 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] |
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In reply to this post by Bill Frantz
Could it have been the battery that was cold and not delivering full output?
Sent from my iPhone ...nr4c. bill > On Oct 4, 2016, at 1:14 AM, Bill Frantz <[hidden email]> wrote: > > During the California QSO Party, the temperatures in our operation tent dropped below freezing. Two of us felt that we were not getting full power out of our K3s when the internal temperatures were low. Given that we were using the K3 to measure power output, low temperatures could be affecting the measurement rather than the power. > > After sending CQ for 5 or 10 minutes, the K3s warmed up and the output power rose to normal. Too bad calling CQ didn't warm the operators as well. HIHI > > Since we were getting about 90% power with the internal temperatures at zero C, it is not a major issue, but we are curious. Has anyone else experienced this effect? > > 73 Bill AE6JV > > ----------------------------------------------------------------------- > Bill Frantz | Concurrency is hard. 12 out | Periwinkle > (408)356-8506 | 10 programmers get it wrong. | 16345 Englewood Ave > www.pwpconsult.com | - Jeff Frantz | Los Gatos, CA 95032 > > ______________________________________________________________ > 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] |
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In reply to this post by Bill Frantz
I've not tried running my K3 at outside temps, but many years ago had
opportunity to test my TS-180S in the cold. I was going out to a remote checkpoint on the Alaska Iditarod Trail (sled dog race to Nome) and my radio stuff did not make the load from one bush town to another so the box with radio sat outside in the snow overnight. When we arrived at the checkpoint which consisted of a wall tent at the edge of a frozen lake, I checked the big round temperature dial put up on a post (it read from -60 to +100F) and the needle say on minimum (-60F). It stayed there for three days so we had no idea how cold it got at night. Snow was three feet deep requiring one to wear snowshoes everywhere. The interior of the tent was warmed by a wood stove (55-gal oil drum converted to stove) to -15F. When I got my station first set up the LCD screen did not work (too cold) so I left it turned off to warm up a little. It worked fine then at -15F inside temp for the rest of the time. The Honda 800w lunch box generator would not budge when the starting rope was pulled...until we sat the generator on top of the stove for an hour to warm up the lubricating oil enough to turn over the engine. Ran fine once warmed and I did not stop it except for a few hours at night while we slept (wore my insulated underwear inside the down sleeping bag with my down parka draped over (like a cocoon). Third day it warmed up to +15F and we were walking around outside in our tee shirts it was "so hot". A day later arriving back in Anchorage where it was +30F the sweat poured off me just wearing my wool shirt and jeans outside. March-1986. I am installing my KX3 in my truck so curious if it will have any issues when cold. Its easy to disconnect and bring into a warm house or trailer so maybe will not have to face that. 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: [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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On 10/4/2016 7:16 PM, Edward R Cole wrote:
I've not tried running my K3 at outside temps, Hello Ed, I would caution you against trying your K3 in those temps. Minus 60 degrees F. is the coldest on record for Minnesota, and you experience far colder that that. The cold may do multiple things to the K3 if it has multi-layer circuit boards. I didn't notice if it does. Our club left a repeater in an unheated enclosure one winter. I would estimate it wasn't much colder than minus 30 degrees F. at that location. (To clarify for others, this is 30 degrees F. below zero.) I have seen what the multi-layer circuit board looked like. More specifically, the thru-the-hole solder connections from one layer to another were cracked. Maybe it was the type of solder used??? I'm sure circuit designs have changed since the first solid state rigs I described in the cold. LCD screens hadn't been heard of yet. I'm surprised they don't freeze and get damaged in your temps. It is interesting to read of your outdoor experiences. 73, Dick, n0ce ______________________________________________________________ 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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Here in Russia we have fun contest called "Frost the Red Nose" where
participants are awarded extra points for low temperatures. A lot of participants operate in below freezing temperatures every year. Stories from some of the participants (pdf file) can be downloaded here http://qrp.ru/files/stories/category/4-froststories?download=292%3Afrost2013 Text is in Russian but there are many pictures that said to be "worth a thousand words". 73, Igor UA9CDC ----- Original Message ----- From: "Richard Fjeld" <[hidden email]> To: <[hidden email]> Sent: Wednesday, October 05, 2016 10:56 AM Subject: Re: [Elecraft] Cold K3 > On 10/4/2016 7:16 PM, Edward R Cole wrote: > I've not tried running my K3 at outside temps, > > Hello Ed, > > I would caution you against trying your K3 in those temps. Minus 60 > degrees F. is the coldest on record for Minnesota, and you experience > far colder that that. The cold may do multiple things to the K3 if it > has multi-layer circuit boards. I didn't notice if it does. > > Our club left a repeater in an unheated enclosure one winter. I would > estimate it wasn't much colder than minus 30 degrees F. at that > location. (To clarify for others, this is 30 degrees F. below zero.) I > have seen what the multi-layer circuit board looked like. More > specifically, the thru-the-hole solder connections from one layer to > another were cracked. Maybe it was the type of solder used??? > > I'm sure circuit designs have changed since the first solid state rigs I > described in the cold. LCD screens hadn't been heard of yet. I'm > surprised they don't freeze and get damaged in your temps. It is > interesting to read of your outdoor experiences. > > 73, > Dick, n0ce > > > > ______________________________________________________________ > 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] |
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In reply to this post by Bill Frantz
Dick,
The KX3 will not see those extreme cold temps. Where we live it rarely drops below -15F and typically is 0 to +10F at night in winter. The KX3 has a RAM bracket in my truck so it might sit outside at night. I was wondering how it would react to being powered on at down to -15F. Truthfully it might not ever face that as I have remote start for the truck to warm up for winter driving so the cab might reach +20 or higher before I would use it. A few miles driving and the cab should be +50 to 60F which is comfortable wearing a winter coat. More than likely I would just bring the radio inside at night if planning to use it the next day. My experience with the TS-180S was that the cold effected the LCD screen so operating was not possible until it warmed. That experience in 1986 was the coldest I have seen in my 36 years up here in AK. Quite possible the temp dropped to -80F at night (-78F is the official record for AK). Fortunately at extreme cold the air is completely calm most of the time. Dog teams coming into the checkpoint reported -45F on the ridge tops but with 30-40mph winds which would feel much colder than what we were down in the lake valley. The coldest I have experience at home on the Kenai Peninsula is -35F and that was nighttime so I stayed inside near the wood stove. I now live in a modern home with force-air natural gas heat and its +67F to +71F year round. Radio gear is std in all vehicles used at Prudhoe Bay on AK's "north slope" but either they leave the engines run continuously or they are plugged in with electric heaters on the inside keeping the interior from freezing. Ever climb into a suburban when the seats are -40F and hard as a rock (a very cold rock)? In fact the seats split apart if allowed to get that cold. Most repeaters up there are enclosed in warmed buildings and only antenna and coax outside. I had fun up there in Nov.1980 installing MOT radios in heavy equipment that was parked outside (it was only -15F so my bare hands took a punishment). After a couple days one of the operators showed me how to start up the engines and I got a little warmth inside the cabs (+15 vs -15). I was young (36) and adventurous - making $6500 in three weeks working 18-hour days didn't hurt, either. 73, Ed - KL7UW From: Richard Fjeld <[hidden email]> To: "[hidden email]" <[hidden email]> Subject: Re: [Elecraft] Cold K3 On 10/4/2016 7:16 PM, Edward R Cole wrote: I've not tried running my K3 at outside temps, Hello Ed, I would caution you against trying your K3 in those temps. Minus 60 degrees F. is the coldest on record for Minnesota, and you experience far colder that that. The cold may do multiple things to the K3 if it has multi-layer circuit boards. I didn't notice if it does. Our club left a repeater in an unheated enclosure one winter. I would estimate it wasn't much colder than minus 30 degrees F. at that location. (To clarify for others, this is 30 degrees F. below zero.) I have seen what the multi-layer circuit board looked like. More specifically, the thru-the-hole solder connections from one layer to another were cracked. Maybe it was the type of solder used??? I'm sure circuit designs have changed since the first solid state rigs I described in the cold. LCD screens hadn't been heard of yet. I'm surprised they don't freeze and get damaged in your temps. It is interesting to read of your outdoor experiences. 73, Dick, n0ce 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: [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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Igor and Ed,
I found your posts interesting. Thank you both. The original thread was about a K3 operating in the cold below freezing temps, and reduced power was observed. I think the question was asked if we could answer why. Someone posted with a question if the battery was cold. That may have been pertinent. I was curious. I posted about what I had been taught years ago concerning solid state circuit design. As of those designs, it is my understanding that solid state radios will have reduced performance in cold temps. I'd like to know if this is true with designs today. Perhaps you, and others, will post some findings on this question as you operate in the cold. (Most radios today, have LCD screens and that will hamper the findings.) 73, Dick, n0ce ______________________________________________________________ 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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On 10/6/2016 10:43 AM, Richard Fjeld wrote:
> Someone posted with a question if the battery was cold. That may have > been pertinent. Nearly all chemical reactions slow with decreasing temperature. Batteries produce an electrical current through chemical reaction(s). In the northern interior of AK, coldest I saw was -67F ... for 10 days. Vehicles idled 24/7 and if one died, it got restarted in the spring. :-) > > I was curious. I posted about what I had been taught years ago > concerning solid state circuit design. As of those designs, it is my > understanding that solid state radios will have reduced performance in > cold temps. Solid state devices have both high and low temperature limits. Switching speeds slow down a low temps. Crystals will also cease oscillating at low enough temperatures. > > I'd like to know if this is true with designs today. Perhaps you, and > others, will post some findings on this question as you operate in the > cold. > > (Most radios today, have LCD screens and that will hamper the findings.) I have an older IC-2800H VHF/UHF radio in my truck. It has a color LCD TV display. The truck is parked on the driveway [a little too long for the garage] and in the winter, I can turn on the radio, and it works, however the display is blank for several minutes until things warm up a little. 73, Fred K6DGW - Sparks NV DM09dn - Northern California Contest Club - CU in the Cal QSO Party 7-8 Oct 2017 - www.cqp.org ______________________________________________________________ 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 Richard Fjeld-2
Dick,
My experience operating K3 at temperature of minus 10C shows that there were no noticeable drop of output power. I did not test it at lower temperatures. 73, Igor UA9CDC ----- Original Message ----- From: "Richard Fjeld" <[hidden email]> To: <[hidden email]> Sent: Thursday, October 06, 2016 10:43 PM Subject: Re: [Elecraft] Cold K3 > Igor and Ed, > > I found your posts interesting. Thank you both. > > The original thread was about a K3 operating in the cold below freezing > temps, and reduced power was observed. I think the question was asked if > we could answer why. > > Someone posted with a question if the battery was cold. That may have > been pertinent. > > I was curious. I posted about what I had been taught years ago > concerning solid state circuit design. As of those designs, it is my > understanding that solid state radios will have reduced performance in > cold temps. > > I'd like to know if this is true with designs today. Perhaps you, and > others, will post some findings on this question as you operate in the > cold. > > (Most radios today, have LCD screens and that will hamper the findings.) > > > 73, > Dick, n0ce > > > > ______________________________________________________________ > 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] |
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In reply to this post by k6dgw
It's nice someone finally acknowledged my post about the battery as part of the culprit.
I too have had LCD screens go blank in the cold. And I realize the electronics have limits as well. But note that many small low power radios are very sensitive to battery voltage. If it's too low, the radio draws more current the get the required power level which draws down the voltage even more, and on, and on. Sent from my iPhone ...nr4c. bill > On Oct 6, 2016, at 2:32 PM, Fred Jensen <[hidden email]> wrote: > >> On 10/6/2016 10:43 AM, Richard Fjeld wrote: >> >> Someone posted with a question if the battery was cold. That may have >> been pertinent. > > Nearly all chemical reactions slow with decreasing temperature. Batteries produce an electrical current through chemical reaction(s). In the northern interior of AK, coldest I saw was -67F ... for 10 days. Vehicles idled 24/7 and if one died, it got restarted in the spring. :-) >> >> I was curious. I posted about what I had been taught years ago >> concerning solid state circuit design. As of those designs, it is my >> understanding that solid state radios will have reduced performance in >> cold temps. > > Solid state devices have both high and low temperature limits. Switching speeds slow down a low temps. Crystals will also cease oscillating at low enough temperatures. >> >> I'd like to know if this is true with designs today. Perhaps you, and >> others, will post some findings on this question as you operate in the >> cold. >> >> (Most radios today, have LCD screens and that will hamper the findings.) > > I have an older IC-2800H VHF/UHF radio in my truck. It has a color LCD TV display. The truck is parked on the driveway [a little too long for the garage] and in the winter, I can turn on the radio, and it works, however the display is blank for several minutes until things warm up a little. > > 73, > > Fred K6DGW > - Sparks NV DM09dn > > - Northern California Contest Club > - CU in the Cal QSO Party 7-8 Oct 2017 > - www.cqp.org > > > ______________________________________________________________ > 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] |
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In reply to this post by Richard Fjeld-2
To answer the battery question. The battery was at about 11.5-12
volts and did not show noticeable voltage sag when transmitting (SSB). Note that all measurements (power and voltage) were taken using the internal meters in the cold K3. 73 Bill AE6JV On 10/6/16 at 10:43 AM, [hidden email] (Richard Fjeld) wrote: >The original thread was about a K3 operating in the cold below >freezing temps, and reduced power was observed. I think the >question was asked if we could answer why. > >Someone posted with a question if the battery was cold. That may have >been pertinent. > >I was curious. I posted about what I had been taught years ago >concerning solid state circuit design. As of those designs, it >is my understanding that solid state radios will have reduced >performance in cold temps. Bill Frantz | "I wish there was a knob on the TV to turn up the 408-356-8506 | intelligence. There's a knob called "brightness", but www.pwpconsult.com | it doesn't work. -- Gallagher ______________________________________________________________ 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 k6dgw
Fred,
What is the typical winter temp when the radio works, but no display? Also, you mentioned crystals not oscillating at cold temps. That may have been happening in the past when I thought it was due to low gain in the oscillator circuits. Thanks, Dick, n0ce On 10/6/2016 1:32 PM, Fred Jensen wrote: > > I have an older IC-2800H VHF/UHF radio in my truck. It has a color > LCD TV display. The truck is parked on the driveway [a little too > long for the garage] and in the winter, I can turn on the radio, and > it works, however the display is blank for several minutes until > things warm up a little. > > 73, > > Fred K6DGW > - Sparks NV DM09dn -- ______________________________________________________________ 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 Igor Sokolov-2
Igor,
Minus 10C is about plus 14F, which is well below freezing. I would think that was adequate for a good test of output at cold temps. The experience that I cited about an early rig not operating for several minutes was at about minus 30C or colder. It may have been pre-vfo days, and could have been the crystal which I had not considered until Fred mentioned it. Thank you, Dick, n0ce On 10/6/2016 2:40 PM, Igor Sokolov wrote: > Dick, > My experience operating K3 at temperature of minus 10C shows that > there were no noticeable drop of output power. I did not test it at > lower temperatures. > > 73, Igor UA9CDC ______________________________________________________________ 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 Nr4c
(Please note something is happening to my use of Thunderbird email
client on my end, so I don't know what is being sent) Yes Bill, I agree with you and the voltage assessment. Back a number of years ago, mobile radios specified 13.8 Volts, and their performance was greatly reduced at 12 Volts when the charging circuit was not operating. Dick, n0ce On 10/6/2016 3:40 PM, Nr4c wrote: > It's nice someone finally acknowledged my post about the battery as part of the culprit. > > I too have had LCD screens go blank in the cold. And I realize the electronics have limits as well. > > But note that many small low power radios are very sensitive to battery voltage. If it's too low, the radio draws more current the get the required power level which draws down the voltage even more, and on, and on. > > Sent from my iPhone > ...nr4c. bill > ______________________________________________________________ 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 Richard Fjeld-2
On 10/6/2016 2:03 PM, Richard Fjeld wrote:
> Fred, > What is the typical winter temp when the radio works, but no display? Guesstimating here ... our highs are currently in the high 60's/low 70's [in the sun] and lows are running in the low 40's/high 30's [all degrees F, we're going metric inch by inch]. The display lit up just fine at 0530 local last Sat when it might have been 38-40 or so in the truck. Last winter, lows were in the low teens, highs in the low 30's, and the display would take 4-5 minutes to brighten up. > > Also, you mentioned crystals not oscillating at cold temps. That may > have been happening in the past when I thought it was due to low gain in > the oscillator circuits. Could be. In Alaska, the luggable Motorola non-tac VHF radios sometimes would fail to work if they weren't warm. A hair blower on the crystals would usually resurrect them. Once the radio was in use, they seemed tp perk along fine ... until my troopers set them down on the ground and froze the batteries. :-) 73, Fred K6DGW - Sparks NV DM09dn - Northern California Contest Club - CU in the Cal QSO Party 7-8 Oct 2017 - www.cqp.org ______________________________________________________________ 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 Edward R Cole
Hi Ed,
We routinely test military/space parts at -55C to +125C. The parts are under voltage and monitored throughout the range. Many of the failures at the very low temp ranges may not be permanent. As the temp is raised the device most of the time functions properly again. There are some anomalies though. We have seen some memory devices work fine at -55C and then lose bits around -40C. And then work fine as the temp rises again. At the high temp end there is greater chance for permanent failure. So, very cold temps can be an issue with any of our gear, especially considering we are using commercial parts. Test temp ranges for semiconductors; Commercial - 0C to +70/80C Automotive - -40C to +125C Military - -55C to +125C 73, N2TK, Tony -----Original Message----- From: Elecraft [mailto:[hidden email]] On Behalf Of Edward R Cole Sent: Thursday, October 06, 2016 12:43 AM To: [hidden email] Subject: Re: [Elecraft] Cold K3 Dick, The KX3 will not see those extreme cold temps. Where we live it rarely drops below -15F and typically is 0 to +10F at night in winter. The KX3 has a RAM bracket in my truck so it might sit outside at night. I was wondering how it would react to being powered on at down to -15F. Truthfully it might not ever face that as I have remote start for the truck to warm up for winter driving so the cab might reach +20 or higher before I would use it. A few miles driving and the cab should be +50 to 60F which is comfortable wearing a winter coat. More than likely I would just bring the radio inside at night if planning to use it the next day. My experience with the TS-180S was that the cold effected the LCD screen so operating was not possible until it warmed. That experience in 1986 was the coldest I have seen in my 36 years up here in AK. Quite possible the temp dropped to -80F at night (-78F is the official record for AK). Fortunately at extreme cold the air is completely calm most of the time. Dog teams coming into the checkpoint reported -45F on the ridge tops but with 30-40mph winds which would feel much colder than what we were down in the lake valley. The coldest I have experience at home on the Kenai Peninsula is -35F and that was nighttime so I stayed inside near the wood stove. I now live in a modern home with force-air natural gas heat and its +67F to +71F year round. Radio gear is std in all vehicles used at Prudhoe Bay on AK's "north slope" but either they leave the engines run continuously or they are plugged in with electric heaters on the inside keeping the interior from freezing. Ever climb into a suburban when the seats are -40F and hard as a rock (a very cold rock)? In fact the seats split apart if allowed to get that cold. Most repeaters up there are enclosed in warmed buildings and only antenna and coax outside. I had fun up there in Nov.1980 installing MOT radios in heavy equipment that was parked outside (it was only -15F so my bare hands took a punishment). After a couple days one of the operators showed me how to start up the engines and I got a little warmth inside the cabs (+15 vs -15). I was young (36) and adventurous - making $6500 in three weeks working 18-hour days didn't hurt, either. 73, Ed - KL7UW From: Richard Fjeld <[hidden email]> To: "[hidden email]" <[hidden email]> Subject: Re: [Elecraft] Cold K3 On 10/4/2016 7:16 PM, Edward R Cole wrote: I've not tried running my K3 at outside temps, Hello Ed, I would caution you against trying your K3 in those temps. Minus 60 degrees F. is the coldest on record for Minnesota, and you experience far colder that that. The cold may do multiple things to the K3 if it has multi-layer circuit boards. I didn't notice if it does. Our club left a repeater in an unheated enclosure one winter. I would estimate it wasn't much colder than minus 30 degrees F. at that location. (To clarify for others, this is 30 degrees F. below zero.) I have seen what the multi-layer circuit board looked like. More specifically, the thru-the-hole solder connections from one layer to another were cracked. Maybe it was the type of solder used??? I'm sure circuit designs have changed since the first solid state rigs I described in the cold. LCD screens hadn't been heard of yet. I'm surprised they don't freeze and get damaged in your temps. It is interesting to read of your outdoor experiences. 73, Dick, n0ce 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: [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] |
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