Re: [Elecraft] K3 COOLING VENTS
Guy Olinger, K2AV wrote: an INTERNAL reading. If 110 F is a fault temperature, then you could destroy your K3 by leaving it out in the sun. That's not a valid comparison. The sort of temperature that will cause rapid damage is 150C for silicon semiconductors, something like 100C for electrolytics, 75C for the 1N34 germanium point contact diodes, if it uses them. These temperatures are reached when the equipment is operating at full power and the insides of the devices are much hotter than the point at which the temperature sensor is placed. If you leave the equipment out in the sun, powered down, and the case temperature reaches 45C, the inside of the semiconductor devices will also be at 45C, well below 150C. It may be lower, because of thermal inertia. Typical consumer equipment is designed to tolerate an air temperature of 45C whilst keeping the core temperature of internal devices well within safety limits. If you actually operate at that sort of temperature, the case temperature and internal temperature will be significantly higher. Leaving electronics exposed to the sun can, of course, result in destroying some of the more temperature sensitive components, as case temperatures can get a lot higher than 45C. Having a large thermal mass will help protect the equipment as the sun should start to go down before the maximum temperature is reached. -- David Woolley The Elecraft list is a forum for the discussion of topics related to Elecraft products and more general topics related ham radio List Guidelines http://www.elecraft.com/elecraft_list_guidelines.htm __ 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
Re: [Elecraft] K3 COOLING VENTS
I believe you make my point perfectly. Folks are complaining about displayed K3 circuit board and PA heat sink temperatures (not air temp) of 35-45 C as if they were somehow dangerous. While individual components can exceed a measured temp spot in a device, good engineering practice in selection of components for their individual dissipation in working circuits will insure that the measured spot is representative so far as safety is concerned across the circuit. In the case of a piece of ham gear, anything not so engineered, e.g. a poorly designed hot spot, will be destroyed by contesters, and broadly complained about, as so well demonstrated over the decades. Aptos is well aware of PVRC and NCCC gossip. : ) Blown solid state finals in HF rigs have been a common complaint in said decades-long gossip stream. By height times width times depth volume the KPA3 is mostly heat sink and a third of the K3 back panel space is fan mount to pull air across said mostly heat sink KPA3. The K3 is a very conservative design, heat-wise. 73, Guy From: David Woolley (E.L) for...@david-woolley.me.uk an INTERNAL reading. If 110 F is a fault temperature, then you could destroy your K3 by leaving it out in the sun. That's not a valid comparison. The sort of temperature that will cause rapid damage is 150C for silicon semiconductors, something like 100C for electrolytics, 75C for the 1N34 germanium point contact diodes, if it uses them. These temperatures are reached when the equipment is operating at full power and the insides of the devices are much hotter than the point at which the temperature sensor is placed. If you leave the equipment out in the sun, powered down, and the case temperature reaches 45C, the inside of the semiconductor devices will also be at 45C, well below 150C. It may be lower, because of thermal inertia. Typical consumer equipment is designed to tolerate an air temperature of 45C whilst keeping the core temperature of internal devices well within safety limits. If you actually operate at that sort of temperature, the case temperature and internal temperature will be significantly higher. Leaving electronics exposed to the sun can, of course, result in destroying some of the more temperature sensitive components, as case temperatures can get a lot higher than 45C. Having a large thermal mass will help protect the equipment as the sun should start to go down before the maximum temperature is reached. __ 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
Re: [Elecraft] K3 COOLING VENTS
Guy, K2AV, wrote: Blown solid state finals in HF rigs have been a common complaint in said decades-long gossip stream. - It would help if we could see their plates glowing red before they failed. Many times I've set the loading on my homebrew rig finals using the color of the plates to decide max power for the duty cycle being used, and I don't recall *ever* having to replace a final tube. Unfortunately, that doesn't work for solid state. Modern rigs are like cars with power steering: you crank the knob and hope the designers did their job so well you don't have to make any judgment calls. That's been true of my K2 for the past decade. The few times they discovered something that could go wrong as more customers like me used (and sometimes abused) the rig, they fixed it with a mod post haste. I expect the same will be true of the K3 over the next decade. Ron AC7AC __ 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
Re: [Elecraft] K3 COOLING VENTS
From: K2ZLS k2...@optonline.net The other driving factor here, that NOBODY seems to take seriously, is the heating effect on the computer chips and DSP processor. They could use heat sinks, but space limitations may be a problem. My background is computers and I know that HEAT is their WORST nightmare. Nobody is a pretty big word to use. There is a real crowd of old f*rts on this reflector that have been in computers since the beginning, and at some point would have killed to get internal temps in heat generating components down (I repeat, down) to the upper 30's, low 40's C. The K3's FP reading is an INTERNAL reading. If 110 F is a fault temperature, then you could destroy your K3 by leaving it out in the sun. My PC is routinely much warmer than the K3, and a lot warmer doing antenna design number crunching. I take temperatures very seriously. I just disagree that the reported FP internal temps are anywhere near a risk. And if the FP temp sensing is in an SM chip, then it is a contact temperature, that will be warmer than the inside air, and even less of a risk. Seems that if I want to buy a K3 used, I'll need to remember to explicitly request no non-stock holes. What you propose would be a deal-killer for me. 73, Guy. __ 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
Re: [Elecraft] K3 COOLING VENTS
I think there are a few points that still need to be considered here How hot are the hot spots? 10 to 20 degrees C above ambient or 50+ degrees above ambient temp. 10 to 20 degrees above ambient temp is nothing to worry about. The dominant heat source is the voltage regulators, adding the Sub RX increases the load on the voltage regulators so they in turn run a bit hotter. The primary cooling mechanism for these voltage regulators is by thermal conduction to the side panel, not by convection. Keep the side-panel cooler and the regulator area will be cooler too. If this is a route you really want to go down then I would propose installing an external finned heatsink on the outside of the K3 in the vicinity of the regulators, reuse the screw holes for the regulator to mount the heatsink, be sure to clean down to metal on the side-panel under the heatskink and use a thermal grease. This will be a lot more efficient than chopping extra holes in the case and if you want to sell your K3 someday all you will need to order is a new side-panel The Sidepanel is in reasonable thermal contact with the rest of the chassis, you may also find that the radio runs cooler if you set the fans on low so they are running all the time at low speed. You could also use a slowly turning external fan to blow air up at the right underside and along the right side of the radio. In my opinion the thermal design of the K3 is just fine the way it is, all components are operating within their thermal specifications by a very wide margin and internal temperature in the vicinity of the ref oscillator stabilises quickly after power on. The K3 runs much cooler than many other radios I have used, it's just that with many other radios the inner chassis is not in good thermal contact with outer chassis so you remain unaware of how hot things are getting around the voltage regulators etc. Warm is fine, too hot to touch is probably not.. -- 73 Brendan EI6IZ __ 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
Re: [Elecraft] K3 COOLING VENTS
On Fri, 15 May 2009 02:58:42 +, Barry VK2BJ wrote: I have already gone down the road of cutting six vertical slots in the right hand side panel to assist with air flow. I would sooner mount a peltier junction on the side panel. But even sooner than that I would just crank up the A/C... I'm an air-conditioned gypsy that's my solution... -- The Who 73, Drew AF2Z __ 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
Re: [Elecraft] K3 COOLING VENTS
An old thought. When trying to get heat out, one usually gets dirt, bugs, etc. in. I like cranking up the AC and leave well enough alone. Of course there is always the freon bath, not. Mel, K6KBE --- On Fri, 5/15/09, drewko drew...@verizon.net wrote: From: drewko drew...@verizon.net Subject: Re: [Elecraft] K3 COOLING VENTS To: ELECRAFT@mailman.qth.net Date: Friday, May 15, 2009, 1:22 PM On Fri, 15 May 2009 02:58:42 +, Barry VK2BJ wrote: I have already gone down the road of cutting six vertical slots in the right hand side panel to assist with air flow. I would sooner mount a peltier junction on the side panel. But even sooner than that I would just crank up the A/C... I'm an air-conditioned gypsy that's my solution... -- The Who 73, Drew AF2Z __ 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 __ 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
[Elecraft] K3 COOLING VENTS
Hi Barry, Thank you for your interest. I have received many replies both good and bad. Bad, because many think I have some kind of heating PROBLEM with the K3. Not so. My only intent is to try lower the FP temp like you. Here's what I found. Your slots are a GOOD start but not enough. No amount of fan speed will bring that temp down. WHY? Well you only have to take the top cover off and try to follow where the air will go. You can't , you say, because the front compartment is isolated from the rear compartment by the panel that goes across the middle. That's my point. The middle panel will also need vents so the air can get back to where the fan is trying to suck it out. There is a tremendous source of fresh air on top of the PA and that's a GOOD thing but, it doesn't allow for a very good draw for air trapped in the front compartment. The fan speed seems more controlled by the PA sensor than the FP sensor. That's a good thing because we've seen that the fan has NO effect on FP temp. Here's what I would like to try. I would open up the side panel above U12 and U13 with slots designed similar to that of the speaker. This pattern is already proven and in use over the top panel and speaker. Open up the bottom panel, just behind the front panel, with a slot similar to those in the rear bottom panel. No big deviation here. Just gives air better access to cool the bottom of the main board. Open up the center internal partition with the same kind of elongated slots like the bottom panel. Now, what you have is the side and bottom slots providing cool air to the front enclosure. The middle partition slots provide a way for the air to be drawn to the rear PA enclosure, to be sucked out by the fan. I don't think this is such a radical change that goes against existing design and I'm sure it will be an improvement. The other driving factor here, that NOBODY seems to take seriously, is the heating effect on the computer chips and DSP processor. They could use heat sinks, but space limitations may be a problem. My background is computers and I know that HEAT is their WORST nightmare. I'm sure you have seen the latest memory sticks with elaborate heat sinks. That's partly due to the high frequency and heat generation affecting the timing latency. But, the idea applies to ALL these device types. You have read all the responses regarding the exploits of all the heat extremes that have been posted saying that nothing bad has happened. But I ask, how many unexplained K3 events requiring restarts and FW reloads can be attributed to this. I can't say but, the potential is there, as long as the heat keeps building up. So again, let me say that there is NOT any PROBLEM with K3. Only that it could, and will get better. 73's cheers and keep the shinny side up.From Tony K2ZLS Barry Simpson wrote: An interesting post Tony. I have exactly the same issues with the right side panel heating up with a typical front panel temperature reaching 43C. This has only happened since installation of the second receiver which virtually cuts off the airflow inside. The front panel typically runs hotter than the PA. I have already gone down the road of cutting six vertical slots in the right hand side panel to assist with air flow. Regrettably it makes no difference to the temperature. The only way to lower the temperature significantly is to have the fans on permanently. This way there is some air sucked through the vents in the panel and I can drop the temp down to the low 30's. Given that the high temperature of the side panel does not appear to have any detrimental effect I have now given up worrying about it. 73 Barry VK2BJ -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of K2ZLS Sent: 14 May 2009 21:06 To: ELECRAFT@mailman.qth.net Subject: [Elecraft] K3 COOLING VENTS Hi, There have been enough posts here about the temperature inside the K3 to start me thinking. Mine also gets very WARM on the right side by U12 and U13. You all know how boxed in the Front side of the K3 has become and now we are looking at additional features being added to the inside of the box. The way the cooling fan is now, there is little or no circulation of air in the front side of the K3. Another poster wanted to add bigger fans but, you know, that will not solve the heat problem because the air can't get to where it needs to go. I would like to CROSS VENTILATE the front area by adding cooling vents, similar to the configuration of the speaker vents, to both side panels. There does not seem to be any worry about RF leakage at the rear vents where the AMP is and the side vents can be fashioned the same way. I know that Wayne feels that the cooling is adequate but, I think this would be a worthy modification at this point
Re: [Elecraft] K3 COOLING VENTS
Hi Tony, We've looked at the fp temp range during the design, testing and now during our ongoing relaibility testing of the K3. There is nothing out of range here and we are very comfortable with it. It is not a reliability issue at these temps, and it certainly not causing any operational issues. We are not stressing the DSP amd FP parts nearly as much as typical PCs do. 73, Eric WA6HHQ _..._ -Original Message- From: K2ZLS k2...@optonline.net Date: Friday, May 15, 2009 7:13 pm Subject: [Elecraft] K3 COOLING VENTS To: ELECRAFT@mailman.qth.net Hi Barry, Thank you for your interest. I have received many replies both good and bad. Bad, because many think I have some kind of heating PROBLEM with the K3. Not so. My only intent is to try lower the FP temp like you. Here's what I found. Your slots are a GOOD start but not enough. No amount of fan speed will bring that temp down. WHY? Well you only have to take the top cover off and try to follow where the air will go. You can't , you say, because the front compartment is isolated from the rear compartment by the panel that goes across the middle. That's my point. The middle panel will also need vents so the air can get back to where the fan is trying to suck it out. There is a tremendous source of fresh air on top of the PA and that's a GOOD thing but, it doesn't allow for a very good draw for air trapped in the front compartment. The fan speed seems more controlled by the PA sensor than the FP sensor. That's a good thing because we've seen that the fan has NO effect on FP temp. Here's what I would like to try. I would open up the side panel above U12 and U13 with slots designed similar to that of the speaker. This pattern is already proven and in use over the top panel and speaker. Open up the bottom panel, just behind the front panel, with a slot similar to those in the rear bottom panel. No big deviation here. Just gives air better access to cool the bottom of the main board. Open up the center internal partition with the same kind of elongated slots like the bottom panel. Now, what you have is the side and bottom slots providing cool air to the front enclosure. The middle partition slots provide a way for the air to be drawn to the rear PA enclosure, to be sucked out by the fan. I don't think this is such a radical change that goes against existing design and I'm sure it will be an improvement. The other driving factor here, that NOBODY seems to take seriously, is the heating effect on the computer chips and DSP processor. They could use heat sinks, but space limitations may be a problem. My background is computers and I know that HEAT is their WORST nightmare. I'm sure you have seen the latest memory sticks with elaborate heat sinks. That's partly due to the high frequency and heat generation affecting the timing latency. But, the idea applies to ALL these device types. You have read all the responses regarding the exploits of all the heat extremes that have been posted saying that nothing bad has happened. But I ask, how many unexplained K3 events requiring restarts and FW reloads can be attributed to this. I can't say but, the potential is there, as long as the heat keeps building up. So again, let me say that there is NOT any PROBLEM with K3. Only that it could, and will get better. 73's cheers and keep the shinny side up.From Tony K2ZLS Barry Simpson wrote: An interesting post Tony. I have exactly the same issues with the right side panel heating up with a typical front panel temperature reaching 43C. This has only happened since installation of the second receiver which virtually cuts off the airflow inside. The front panel typically runs hotter than the PA. I have already gone down the road of cutting six vertical slots in the right hand side panel to assist with air flow. Regrettably it makes no difference to the temperature. The only way to lower the temperature significantly is to have the fans on permanently. This way there is some air sucked through the vents in the panel and I can drop the temp down to the low 30's. Given that the high temperature of the side panel does not appear to have any detrimental effect I have now given up worrying about it. 73 Barry VK2BJ -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of K2ZLS Sent: 14 May 2009 21:06 To: ELECRAFT@mailman.qth.net Subject: [Elecraft] K3 COOLING VENTS Hi, There have been enough posts here about the temperature inside the K3 to start me thinking. Mine also gets very WARM on the right side by U12 and U13. You all know how boxed in the Front side of the K3 has become and now we are looking at additional features being added to the inside of the box. The way the cooling fan is now, there is little or no circulation of air in the front side
Re: [Elecraft] K3 COOLING VENTS
Hi Tony, We've looked at the fp temp range during the design, testing and now during our ongoing relaibility testing of the K3. There is nothing out of range here and we are very comfortable with it. It is not a reliability issue at these temps, and it certainly not causing any operational issues. We are not stressing the DSP amd FP parts nearly as much as typical PCs do. 73, Eric WA6HHQ _..._ -Original Message- From: K2ZLS k2...@optonline.net Date: Friday, May 15, 2009 7:13 pm Subject: [Elecraft] K3 COOLING VENTS To: ELECRAFT@mailman.qth.net __ 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
Re: [Elecraft] K3 COOLING VENTS
On Fri, 2009-05-15 at 19:13 -0400, K2ZLS wrote: The other driving factor here, that NOBODY seems to take seriously, is the heating effect on the computer chips and DSP processor. They could use heat sinks, but space limitations may be a problem. My background is computers and I know that HEAT is their WORST nightmare. My PC consumes well over 200W of power when running hard, My graphics subsystem another 80-100W or so when stressed. almost all of this dissipation is confined to a few very small areas, this is a heat problem. My i7 CPU with a big heatsink and fan on it stabilises at 57C when working hard (~35 degrees C above ambient temp) My K3 with Sub consumes under 15W in receive, the front panel temp stabilises at around 14 Degrees above ambient temp after being on a while. this is not a heat problem, no matter how you look at it. If it makes you happy, cool the case externally. the side panels are in good thermal contact with the internal screen between the Front panel area and the rest of the radio so this will also lower the temp in the front panel area. Cut slots or holes in there and you will have a new set of issues to deal with, namely EMC issues with digital trash from the front panel DSP / CPU areas getting back into the receiver. -- 73 Brendan EI6IZ __ 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
[Elecraft] K3 COOLING VENTS
Hi, There have been enough posts here about the temperature inside the K3 to start me thinking. Mine also gets very WARM on the right side by U12 and U13. You all know how boxed in the Front side of the K3 has become and now we are looking at additional features being added to the inside of the box. The way the cooling fan is now, there is little or no circulation of air in the front side of the K3. Another poster wanted to add bigger fans but, you know, that will not solve the heat problem because the air can't get to where it needs to go. I would like to CROSS VENTILATE the front area by adding cooling vents, similar to the configuration of the speaker vents, to both side panels. There does not seem to be any worry about RF leakage at the rear vents where the AMP is and the side vents can be fashioned the same way. I know that Wayne feels that the cooling is adequate but, I think this would be a worthy modification at this point, if only to let the HOT AIR ...OUT. If someone knows how to punch out this configuration, I would gladly supply the panels and pay any costs involved. 73's and Thanks. Tony K2ZLS at OPTONLINE dot NET __ 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
Re: [Elecraft] K3 COOLING VENTS
On Thu, 2009-05-14 at 17:05 -0400, K2ZLS wrote: Hi, There have been enough posts here about the temperature inside the K3 to start me thinking. Mine also gets very WARM on the right side by U12 and U13. --snip-- I think this would be a worthy modification at this point, if only to let the HOT AIR ...OUT. Don't do it, it's not needed and it may mess up air circulation elsewhere causing hot spots. The heat at this location is not hot air inside making the case warm it's the side of the case being used as an (ample) heat-sink for the directly attached Voltage regulators. Warmth here IS NOT a symptom of much hotter stuff inside as would have been the case with a 'hollow state' radio, simply that the side panel is working as intended to heatsink the voltage regulators bolted directly to it. -- 73 Brendan EI6IZ __ 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
Re: [Elecraft] K3 COOLING VENTS
The reason that side feels warm is because the side itself is the heat sink for the regulators, moving the heat out of the K3 through the metal. There's absolutely no problem with the rig feeling warm. In fact, it's good. It keeps everything inside dry and stable. Ron AC7AC --- --Original Message- There have been enough posts here about the temperature inside the K3 to start me thinking. Mine also gets very WARM on the right side by U12 and U13. ... I would like to CROSS VENTILATE the front area by adding cooling vents, similar to the configuration of the speaker vents, 73's and Thanks. Tony K2ZLS at OPTONLINE dot NET __ __ 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
[Elecraft] K3 COOLING VENTS
Thanks to Brendan and all the responders: I have received several answers similar to yours regarding the heat sink effect. But, I already knew that. The reason I'm bringing this up is that the concern for hot spots is already there. After running the K3 hard, try powering down, remove power and the top cover. Feel around the front side and you will notice the warmth of the display, the other boards and the KRX3 box, which has NO ventilation inside and is a heat sink by itself. If you examine the air flow you can't help but see that the air movement DOESN'T GET to these areas. It's concentrated in the area around the AMP enclosure. That's my point. The K3 CAN be improved if a little more attention is paid to draining this heat supply more efficiently instead of accepting the rise in heat as a GOOD thing. I think improving the ventilation is the key here and maybe you are right, my idea of cross ventilation may not be the best thing. Maybe, instead of drawing ALL cooling air from the top opening, a side vent is installed to provide an additional source of cooling air that will find its own way to the output fans. The balance in the size of the openings is important to regulating the air flow. 73's From Tony __ 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
Re: [Elecraft] K3 COOLING VENTS
I think another important point is the ambient temperature calibration. If that is off (the K3 thinks 30c is 15c) the fans may not come in when they should. Dave Wilburn NM4M K2ZLS wrote: Thanks to Brendan and all the responders: I have received several answers similar to yours regarding the heat sink effect. But, I already knew that. The reason I'm bringing this up is that the concern for hot spots is already there. After running the K3 hard, try powering down, remove power and the top cover. Feel around the front side and you will notice the warmth of the display, the other boards and the KRX3 box, which has NO ventilation inside and is a heat sink by itself. If you examine the air flow you can't help but see that the air movement DOESN'T GET to these areas. It's concentrated in the area around the AMP enclosure. That's my point. The K3 CAN be improved if a little more attention is paid to draining this heat supply more efficiently instead of accepting the rise in heat as a GOOD thing. I think improving the ventilation is the key here and maybe you are right, my idea of cross ventilation may not be the best thing. Maybe, instead of drawing ALL cooling air from the top opening, a side vent is installed to provide an additional source of cooling air that will find its own way to the output fans. The balance in the size of the openings is important to regulating the air flow. 73's From Tony __ 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 __ 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
Re: [Elecraft] K3 COOLING VENTS
An interesting post Tony. I have exactly the same issues with the right side panel heating up with a typical front panel temperature reaching 43C. This has only happened since installation of the second receiver which virtually cuts off the airflow inside. The front panel typically runs hotter than the PA. I have already gone down the road of cutting six vertical slots in the right hand side panel to assist with air flow. Regrettably it makes no difference to the temperature. The only way to lower the temperature significantly is to have the fans on permanently. This way there is some air sucked through the vents in the panel and I can drop the temp down to the low 30's. Given that the high temperature of the side panel does not appear to have any detrimental effect I have now given up worrying about it. 73 Barry VK2BJ -Original Message- From: elecraft-boun...@mailman.qth.net [mailto:elecraft-boun...@mailman.qth.net] On Behalf Of K2ZLS Sent: 14 May 2009 21:06 To: ELECRAFT@mailman.qth.net Subject: [Elecraft] K3 COOLING VENTS Hi, There have been enough posts here about the temperature inside the K3 to start me thinking. Mine also gets very WARM on the right side by U12 and U13. You all know how boxed in the Front side of the K3 has become and now we are looking at additional features being added to the inside of the box. The way the cooling fan is now, there is little or no circulation of air in the front side of the K3. Another poster wanted to add bigger fans but, you know, that will not solve the heat problem because the air can't get to where it needs to go. I would like to CROSS VENTILATE the front area by adding cooling vents, similar to the configuration of the speaker vents, to both side panels. There does not seem to be any worry about RF leakage at the rear vents where the AMP is and the side vents can be fashioned the same way. I know that Wayne feels that the cooling is adequate but, I think this would be a worthy modification at this point, if only to let the HOT AIR ...OUT. If someone knows how to punch out this configuration, I would gladly supply the panels and pay any costs involved. 73's and Thanks. Tony K2ZLS at OPTONLINE dot NET __ 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 __ 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
