KX3 and Digital Modea
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I am on my second KX3, having sold the first one and then find myself missing it. However, I now find the KX3 routinely overheats in digital modes. Specifically, at just 5 watts on WSPR with transmission time of 2 minutes (as regulated by WSPR software) the KX3 overheats "HI TEMP" at a minute and a half, resulting in a safety shutdown of the rig. This radio has a wonderful built-in digital capability, but digital appears beyond the rig's ability, save CW which is my main digital interest anyway. I would like to use the KX3 occasionally on PSK, JT65 and WSPR without the absurdity of having to buy an after-market heat sink to replace a factory installed heat sink. There is no guarantee the after-market one is superior, and it shouldn't be necessary since a radio with a digital capability should not need some after-market accessory to enable the advertised digital mode. I wonder if anyone has found a firmware or software answer to the over heating problem. The overheating problem happens regularly in digital modes and I believe comments about the KX3 working correctly in digital are simply incorrect. This is not an antenna issue and not an SWR issue. Thanks Ron KM4VX
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I have adopted a plan in that regard. On digital modes I run my K3/100
adjusted to the point the PA just kicks in (around 12-13 watts). At that point the 100W PA is loafing along and as far as I can determine exhibits no overheating no matter how long a transmission I make on PSK31 or any of the digital modes. I believe the 100W PA to be fixed gain and the lower drive requirements at that power level lets the 10W driver amp in the K3 loaf along at a significantly reduced level. Perhaps WSPR frowns on such "high power" and this would not be applicable? 73s, Jim W4ATK K-Line On 7/20/2015 8:28 AM, KM4VX wrote: > I am on my second KX3, having sold the first one and then find myself > missing it. However, I now find the KX3 routinely overheats in digital > modes. Specifically, at just 5 watts on WSPR with transmission time of 2 > minutes (as regulated by WSPR software) the KX3 overheats "HI TEMP" at a > minute and a half, resulting in a safety shutdown of the rig. This radio has > a wonderful built-in digital capability, but digital appears beyond the > rig's ability, save CW which is my main digital interest anyway. I would > like to use the KX3 occasionally on PSK, JT65 and WSPR without the absurdity > of having to buy an after-market heat sink to replace a factory installed > heat sink. There is no guarantee the after-market one is superior, and it > shouldn't be necessary since a radio with a digital capability should not > need some after-market accessory to enable the advertised digital mode. I > wonder if anyone has found a firmware or software answer to the over heating > problem. The overheating problem happens regularly in digital modes and I > believe comments about the KX3 working correctly in digital are simply > incorrect. This is not an antenna issue and not an SWR issue. Thanks Ron > KM4VX > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/KX3-and-Digital-Modea-tp7605122.html > Sent from the Elecraft mailing list archive at 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] |
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In reply to this post by KM4VX
The KX3 operates well in most environments in modes with reasonable
key-down times. Recognizing that more and more operators are using digital modes with extended key-down times, we recently replaced the supplied heat sink of the KX3 with one having significantly more thermal mass and radiation surface area. If your KX3 is an earlier one, and your operating preferences require longer key-down times at higher power levels than your thermal environment can reasonably handle, the improved heat sink is available at a nominal cost. An alternative is to run a bit less than 5 watts and find the balance of transmit time, local environment and mode preferences that work for you. Being a weak-signal mode, WSPR at 3 or even 4 watts is likely to work well for you with the radio as-is. In the end, this is a thermal management issue, not a firmware or software problem. 73, Lyle KK7P > I am on my second KX3, having sold the first one and then find myself > missing it. However, I now find the KX3 routinely overheats in digital > modes... ______________________________________________________________ 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 KM4VX
.I tried my KX3 on digi modes and gave it up for this reason. I could run my FT-817 all day,but can't get 5 minutes from the KX3 at 5w..heck,I've even had mine shut down running ssb on 6m outside in the summer.
Only "cure" I found was to run about 1 watt or less Scott W0SGM
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In reply to this post by KM4VX
Has the Temperature Compensation been done on that KX3 ??
http://www.elecraft.com/manual/KX3%20Custom%20VFO%20TC%20rev%20A9.pdf I routinely run m KX3 at 5 watts using WSPR & WSJT-X for JT65/JT9 modes. The Temperature Compensation has been done, along with the replacement of the standard heat sink with an aftermarket one. By adding a 12 volt fan salvaged from an old desktop computer, I run JT9 at 10 watts into Europe without issues. Neil Z KN3ILZ On 07/20/15 09:28 am, KM4VX wrote: > I am on my second KX3, having sold the first one and then find myself > missing it. However, I now find the KX3 routinely overheats in digital > modes. Specifically, at just 5 watts on WSPR with transmission time of 2 > minutes (as regulated by WSPR software) the KX3 overheats "HI TEMP" at a > minute and a half, resulting in a safety shutdown of the rig. This radio has > a wonderful built-in digital capability, but digital appears beyond the > rig's ability, save CW which is my main digital interest anyway. I would > like to use the KX3 occasionally on PSK, JT65 and WSPR without the absurdity > of having to buy an after-market heat sink to replace a factory installed > heat sink. There is no guarantee the after-market one is superior, and it > shouldn't be necessary since a radio with a digital capability should not > need some after-market accessory to enable the advertised digital mode. I > wonder if anyone has found a firmware or software answer to the over heating > problem. The overheating problem happens regularly in digital modes and I > believe comments about the KX3 working correctly in digital are simply > incorrect. This is not an antenna issue and not an SWR issue. Thanks Ron > KM4VX > > > > -- > View this message in context: http://elecraft.365791.n2.nabble.com/KX3-and-Digital-Modea-tp7605122.html > Sent from the Elecraft mailing list archive at 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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In reply to this post by W0SGM
Lyle: Thank you. My KX3 was purchased last week so I am confident it has the new heat sink. I have adjusted WSPR to 3 watts and it works. Since the radio does warm up I am going to use a computer fan to aid the heat sink. I believe Elecraft should have upgraded to a better heat sink. I do not place faith in the after-market ones but it is what it is. 73. Ron
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In reply to this post by KM4VX
Since I carry my KX3 into the backwoods, I am glad mine doesn't have
a heavier heat sink that is an aid to high duty cycle digital modes. Easy enough to blow some air by it when not portable to avoid the issues in those modes. To each his own. Chip AE5KA ______________________________________________________________ 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: KX3 and Digital Modea
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In reply to this post by KM4VX
Ron, I don't have a KX3, but from what I can recall, everyone who has ran that" Temp Compensation deal " has been very satisfied and said that it helps .
Maybe someone who has done the compensation could comment . ((((73))))) Milverton. /W9MMS. From: KM4VX <[hidden email]> To: [hidden email] Sent: Monday, July 20, 2015 4:50 PM Subject: Re: [Elecraft] KX3 and Digital Modea Lyle: Thank you. My KX3 was purchased last week so I am confident it has the new heat sink. I have adjusted WSPR to 3 watts and it works. Since the radio does warm up I am going to use a computer fan to aid the heat sink. I believe Elecraft should have upgraded to a better heat sink. I do not place faith in the after-market ones but it is what it is. 73. Ron -- View this message in context: http://elecraft.365791.n2.nabble.com/KX3-and-Digital-Modea-tp7605122p7605158.html Sent from the Elecraft mailing list archive at 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] |
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In reply to this post by W0SGM
I have yet to encounter a "thermal shutdown". The only time I had a
power fallback was in France during an extended CW QSO with my brother at an ambient temperature of 31 degrees Celsius. I did the temp. calibration by the way. KX3 nr 3244. Never whispered with it, I have a dedicated TX for that with 100 mW output. Has been reported in YB, VK and ZL amongst many others on 20 metres using a 2x20m dipole with open line. Cheers, Peter Op 2015-07-20 22:53 schreef W0SGM via Elecraft: > .I tried my KX3 on digi modes and gave it up for this reason. I could run my > FT-817 all day,but can't get 5 minutes from the KX3 at 5w..heck,I've even > had mine shut down running ssb on 6m outside in the summer. > Only "cure" I found was to run about 1 watt or less > Scott W0SGM ______________________________________________________________ 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 Elecraft mailing list
The extended Temp Compensation will not help with a hi temperature problem.
What it will do is reduce the frequency drift over a wide frequency range - so for maintaining frequency stability while the KX3 is heating up, yes that stability will be increased. The temperature problem with extended transmit 'key down' times is what is causing the heating. Cooling the PA transistors or reducing the power is is the only way to reduce the effects of high temperature. The new heatsink will help, lowering the power will help, a fan blowing on the heatsink will help, an aftermarket heatsink will help. Anything to keep the PA transistors cooler. 73, Don W3FPR On 7/20/2015 6:39 PM, Milverton M. Swire via Elecraft wrote: > Ron, I don't have a KX3, but from what I can recall, everyone who has ran that" Temp Compensation deal " has been very satisfied and said that it helps . > Maybe someone who has done the compensation could comment . > ______________________________________________________________ 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 KM4VX
Ron the problem is that digital modes run "key-down" for long periods
of time. No radio (except an Alpha amp is designed to do that). As Lyle states it is a thermal issue and not a digital design issue. Either run less power to keep from overheating or consider installing a bigger heat sink. I opted for the bigger heat sink from VE7FMN (link on my KX3 webpage. It was easy to install (a couple bolts using a allen wrench which he can supply). I have tested running 5w on 6m for extended time and difficult to reach overtemp with the new heat sink. http://www.kl7uw.com/KX3.htm Testing duplicated running JT65 which is key-down about 50-seconds followed by 70-seconds in receive. If you are running psk31 you may have to limit the time you send text in one period. WSPR is the most demanding with 2-min key-down Tx periods. I have not run the KX3 in WSPR as I usually use my K3/10 which may have different heat sink characteristics. 73, Ed - KL7UW --------------------- From: KM4VX <[hidden email]> To: [hidden email] Subject: [Elecraft] KX3 and Digital Modea Message-ID: <[hidden email]> Content-Type: text/plain; charset=us-ascii I am on my second KX3, having sold the first one and then find myself missing it. However, I now find the KX3 routinely overheats in digital modes. Specifically, at just 5 watts on WSPR with transmission time of 2 minutes (as regulated by WSPR software) the KX3 overheats "HI TEMP" at a minute and a half, resulting in a safety shutdown of the rig. This radio has a wonderful built-in digital capability, but digital appears beyond the rig's ability, save CW which is my main digital interest anyway. I would like to use the KX3 occasionally on PSK, JT65 and WSPR without the absurdity of having to buy an after-market heat sink to replace a factory installed heat sink. There is no guarantee the after-market one is superior, and it shouldn't be necessary since a radio with a digital capability should not need some after-market accessory to enable the advertised digital mode. I wonder if anyone has found a firmware or software answer to the over heating problem. The overheating problem happens regularly in digital modes and I believe comments about the KX3 working correctly in digital are simply incorrect. This is not an antenna issue and not an SWR issue. Thanks Ron KM4VX 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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