KPA500 thermal clicks
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The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical.
In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? 73, Andy k3wyc ______________________________________________________________ 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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See page 14, paragraph 2 under Operation. ".......you may hear audible
clicking sounds as the amplifier components cool. This is normal." Mine does, depending on the operating conditions. I see TEMP values about 60º C during heavy FT-8 operation at 450 watts. The fan increments to #3 during the operation. I consider all of this to be normal. I run the FAN CTL at #1. 73 Bob, K4TAX KPA-500 s/n 3519 On 7/17/2018 6:56 AM, ANDY DURBIN wrote: > The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. > > > In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. > > > I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. > > > I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? > > > 73, > > Andy k3wyc > ______________________________________________________________ > 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 ANDY DURBIN
Based upon my experience you will get a lot of disbelief in this forum.
Nevertheless, I have heard similar, but under somewhat different circumstances. See: http://elecraft.365791.n2.nabble.com/KPA500-clicking-td7596512.html I can't explain your issue with this explanation unless your system is actually going into and out of TX during FT8 cycles. This shouldn't be, but who knows? I would give it a try on CW and see if you hear it following keying. Wes N7WS On 7/17/2018 4:56 AM, ANDY DURBIN wrote: > The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. > > > In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. > > > I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. > > > I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? > > > 73, > > Andy k3wyc > ______________________________________________________________ > 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 ANDY DURBIN
“Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second.
Sent from my iPhone ...nr4c. bill > On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: > > The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. > > > In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. > > > I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. > > > I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? > > > 73, > > Andy k3wyc > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 thermal clicks
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While possibly my imagination, after a few months of use I loosened all of the Z bracket to heatsink screws and side panel to heatsink screws and then retightened all of them plus the top cover to Z bracket screws. That seemed to reduce the clicking.
Very 73 - Mike - K9JRI > On Jul 17, 2018, at 9:05 AM, Nr4c <[hidden email]> wrote: > > “Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. > > Sent from my iPhone > ...nr4c. bill > > >> On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: >> >> The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. >> >> >> In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. >> >> >> I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. >> >> >> I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? >> >> >> 73, >> >> Andy k3wyc >> ______________________________________________________________ >> 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] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
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I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode.
73 DOUG EI2CN Sent from my Samsung Galaxy smartphone. -------- Original message --------From: Michael Blake via Elecraft <[hidden email]> Date: 17/07/2018 14:12 (GMT+00:00) To: Nr4c <[hidden email]> Cc: Elecraft Reflector <[hidden email]>, ANDY DURBIN <[hidden email]> Subject: Re: [Elecraft] KPA500 thermal clicks While possibly my imagination, after a few months of use I loosened all of the Z bracket to heatsink screws and side panel to heatsink screws and then retightened all of them plus the top cover to Z bracket screws. That seemed to reduce the clicking. Very 73 - Mike - K9JRI > On Jul 17, 2018, at 9:05 AM, Nr4c <[hidden email]> wrote: > > “Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. > > Sent from my iPhone > ...nr4c. bill > > >> On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: >> >> The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. >> >> >> In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. >> >> >> I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. >> >> >> I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? >> >> >> 73, >> >> Andy k3wyc >> ______________________________________________________________ >> 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] ______________________________________________________________ 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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yes... Weak Signal, not low power. The EME boys use 1 KW.
73s and thanks, Dave NK7Z https://www.nk7z.net On 07/17/2018 07:15 AM, turnbull wrote: > I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. > 73 DOUG EI2CN > > > Sent from my Samsung Galaxy smartphone. > -------- Original message --------From: Michael Blake via Elecraft <[hidden email]> Date: 17/07/2018 14:12 (GMT+00:00) To: Nr4c <[hidden email]> Cc: Elecraft Reflector <[hidden email]>, ANDY DURBIN <[hidden email]> Subject: Re: [Elecraft] KPA500 thermal clicks > While possibly my imagination, after a few months of use I loosened all of the Z bracket to heatsink screws and side panel to heatsink screws and then retightened all of them plus the top cover to Z bracket screws. That seemed to reduce the clicking. > > Very 73 - Mike - K9JRI > > > > >> On Jul 17, 2018, at 9:05 AM, Nr4c <[hidden email]> wrote: >> >> “Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. >> >> Sent from my iPhone >> ...nr4c. bill >> >> >>> On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: >>> >>> The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. >>> >>> >>> In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. >>> >>> >>> I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. >>> >>> >>> I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? >>> >>> >>> 73, >>> >>> Andy k3wyc >>> ______________________________________________________________ >>> 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] > > ______________________________________________________________ > 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] > 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
"“Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. "
I'd appreciate a pointer to any discussions of Z bracket clicks. My search didn't find anything. I have 2 clocks on the wall they tick every second. My brain is able to completely tune them out. The thermal clicks are *much* louder than my clocks and are not regular. My brain locks in on them immediately. 73, Andy k3wyc ________________________________ From: Nr4c <[hidden email]> Sent: Tuesday, July 17, 2018 6:05 AM To: ANDY DURBIN Cc: [hidden email] Subject: Re: [Elecraft] KPA500 thermal clicks “Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. Sent from my iPhone ...nr4c. bill > On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: > > The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. > > > In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. > > > I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. > > > I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? > > > 73, > > Andy k3wyc > ______________________________________________________________ > Elecraft mailing list > Home: http://mailman.qth.net/mailman/listinfo/elecraft > Help: http://mailman.qth.net/mmfaq.htm > Post: mailto:[hidden email] > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > Message delivered to [hidden email] ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[hidden email] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to [hidden email] |
Re: KPA500 thermal clicks
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In reply to this post by Doug Turnbull
FT8 is a weak signal mode. That does not always equate to low power. I have seen many instances on 6M where 400 watts resulted in a -15 signal report from the far end.
Many of the K1JT modes started with moon bounce where it often took 1500 watts to get a weak signal back. Very 73 - Mike - K9JRI > On Jul 17, 2018, at 10:15 AM, turnbull <[hidden email]> wrote: > > I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. > > 73 DOUG EI2CN > > > > Sent from my Samsung Galaxy smartphone. > > -------- Original message -------- > From: Michael Blake via Elecraft <[hidden email]> > Date: 17/07/2018 14:12 (GMT+00:00) > To: Nr4c <[hidden email]> > Cc: Elecraft Reflector <[hidden email]>, ANDY DURBIN <[hidden email]> > Subject: Re: [Elecraft] KPA500 thermal clicks > > While possibly my imagination, after a few months of use I loosened all of the Z bracket to heatsink screws and side panel to heatsink screws and then retightened all of them plus the top cover to Z bracket screws. That seemed to reduce the clicking. > > Very 73 - Mike - K9JRI > > > > > > On Jul 17, 2018, at 9:05 AM, Nr4c <[hidden email]> wrote: > > > > “Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. > > > > Sent from my iPhone > > ...nr4c. bill > > > > > >> On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: > >> > >> The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. > >> > >> > >> In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. > >> > >> > >> I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. > >> > >> > >> I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? > >> > >> > >> 73, > >> > >> Andy k3wyc > >> ______________________________________________________________ > >> 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] > > ______________________________________________________________ > 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 Doug Turnbull
You are wrong. It is (can be) a weak-signal mode.
Wes N7WS On 7/17/2018 7:15 AM, turnbull wrote: > I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. > 73 DOUG EI2CN > > ______________________________________________________________ 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 Doug Turnbull
“Low signal” mode. Doesn’t necessarily mean “low power”. Signal strength can be affected by many things.
Sent from my iPhone ...nr4c. bill > On Jul 17, 2018, at 10:15 AM, turnbull <[hidden email]> wrote: > > I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. > > 73 DOUG EI2CN > > > > Sent from my Samsung Galaxy smartphone. > > -------- Original message -------- > From: Michael Blake via Elecraft <[hidden email]> > Date: 17/07/2018 14:12 (GMT+00:00) > To: Nr4c <[hidden email]> > Cc: Elecraft Reflector <[hidden email]>, ANDY DURBIN <[hidden email]> > Subject: Re: [Elecraft] KPA500 thermal clicks > > While possibly my imagination, after a few months of use I loosened all of the Z bracket to heatsink screws and side panel to heatsink screws and then retightened all of them plus the top cover to Z bracket screws. That seemed to reduce the clicking. > > Very 73 - Mike - K9JRI > > > > > > On Jul 17, 2018, at 9:05 AM, Nr4c <[hidden email]> wrote: > > > > “Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. > > > > Sent from my iPhone > > ...nr4c. bill > > > > > >> On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: > >> > >> The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. > >> > >> > >> In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. > >> > >> > >> I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. > >> > >> > >> I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? > >> > >> > >> 73, > >> > >> Andy k3wyc > >> ______________________________________________________________ > >> 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] > > ______________________________________________________________ > 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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I agree but many people are suffering from wide FT8 signals from others with strong signals. Joe Taylor in his application notes refered to FT8 as a low power mode.
Now we run powdr in the normal FT8 mode and then suffer from others doing the same. I am not an expert in this but it seems there is a problem. The stink given out about other locals in the greater Dublin area is bothersome. This is especially true on six. Sent from my Samsung Galaxy smartphone. -------- Original message --------From: Nr4c <[hidden email]> Date: 17/07/2018 16:33 (GMT+00:00) To: turnbull <[hidden email]> Cc: Michael Blake <[hidden email]>, Elecraft Reflector <[hidden email]>, ANDY DURBIN <[hidden email]> Subject: Re: [Elecraft] KPA500 thermal clicks “Low signal” mode. Doesn’t necessarily mean “low power”. Signal strength can be affected by many things. Sent from my iPhone...nr4c. bill On Jul 17, 2018, at 10:15 AM, turnbull <[hidden email]> wrote: I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. 73 DOUG EI2CN Sent from my Samsung Galaxy smartphone. -------- Original message --------From: Michael Blake via Elecraft <[hidden email]> Date: 17/07/2018 14:12 (GMT+00:00) To: Nr4c <[hidden email]> Cc: Elecraft Reflector <[hidden email]>, ANDY DURBIN <[hidden email]> Subject: Re: [Elecraft] KPA500 thermal clicks While possibly my imagination, after a few months of use I loosened all of the Z bracket to heatsink screws and side panel to heatsink screws and then retightened all of them plus the top cover to Z bracket screws. That seemed to reduce the clicking. Very 73 - Mike - K9JRI > On Jul 17, 2018, at 9:05 AM, Nr4c <[hidden email]> wrote: > > “Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. > > Sent from my iPhone > ...nr4c. bill > > >> On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: >> >> The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. >> >> >> In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. >> >> >> I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. >> >> >> I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? >> >> >> 73, >> >> Andy k3wyc >> ______________________________________________________________ >> 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] ______________________________________________________________ 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 NK7Z
EME boys fave a lot of patb loss and their Yagis point to the moon. For terrestrial worm, the path loss is generally much lower and especially when there are othdf local hams or good propagation the signal levels can be high. This often leads to excessively wide signals on different audio frequencies.
Sent from my Samsung Galaxy smartphone. -------- Original message --------From: "Dave Cole (NK7Z)" <[hidden email]> Date: 17/07/2018 15:30 (GMT+00:00) To: [hidden email] Subject: Re: [Elecraft] KPA500 thermal clicks yes... Weak Signal, not low power. The EME boys use 1 KW. 73s and thanks, Dave NK7Z https://www.nk7z.net On 07/17/2018 07:15 AM, turnbull wrote: > I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. > 73 DOUG EI2CN > > > Sent from my Samsung Galaxy smartphone. > -------- Original message --------From: Michael Blake via Elecraft <[hidden email]> Date: 17/07/2018 14:12 (GMT+00:00) To: Nr4c <[hidden email]> Cc: Elecraft Reflector <[hidden email]>, ANDY DURBIN <[hidden email]> Subject: Re: [Elecraft] KPA500 thermal clicks > While possibly my imagination, after a few months of use I loosened all of the Z bracket to heatsink screws and side panel to heatsink screws and then retightened all of them plus the top cover to Z bracket screws. That seemed to reduce the clicking. > > Very 73 - Mike - K9JRI > > > > >> On Jul 17, 2018, at 9:05 AM, Nr4c <[hidden email]> wrote: >> >> “Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. >> >> Sent from my iPhone >> ...nr4c. bill >> >> >>> On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: >>> >>> The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. >>> >>> >>> In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. >>> >>> >>> I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. >>> >>> >>> I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? >>> >>> >>> 73, >>> >>> Andy k3wyc >>> ______________________________________________________________ >>> 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] > > ______________________________________________________________ > 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] > 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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If one presumes that everyone keeps their audio levels set correctly so
they're not splattering or wide (not always the case, but presume for a moment), I've had better success with digital modes by turning the AGC OFF, so a strong signal doesn't cause a damping reaction (it won't swamp the other stations). This has worked when another station near me (QRP) shared the band on FT8, which would have blocked anyone else (worst case). If you monitor (listen) to the band on digital, turn your speakers down FIRST! ;-) Also never use noise reduction or blanking in digital, it causes distortion and may often produce ghosts in the audio (you decode them on multiple audio frequencies). Rick nhc On 7/17/2018 8:59 AM, turnbull wrote: > EME boys fave a lot of patb loss and their Yagis point to the moon. For terrestrial worm, the path loss is generally much lower and especially when there are othdf local hams or good propagation the signal levels can be high. This often leads to excessively wide signals on different audio frequencies. > > ______________________________________________________________ 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 Doug Turnbull
Makes sense. Seems like high power isn’t in the spirit of the mode. High power is bound to affect many just to make that one high power but weak signal contact now instead of trying at another time.
As well, working all countries with high power in one evening doesn’t seem in the spirit either. Chuck KE9UW Sent from my iPhone, cjack > On Jul 17, 2018, at 10:59 AM, turnbull <[hidden email]> wrote: > > EME boys fave a lot of patb loss and their Yagis point to the moon. For terrestrial worm, the path loss is generally much lower and especially when there are othdf local hams or good propagation the signal levels can be high. This often leads to excessively wide signals on different audio frequencies. > > > Sent from my Samsung Galaxy smartphone. > -------- Original message --------From: "Dave Cole (NK7Z)" <[hidden email]> Date: 17/07/2018 15:30 (GMT+00:00) To: [hidden email] Subject: Re: [Elecraft] KPA500 thermal clicks > yes... Weak Signal, not low power. The EME boys use 1 KW. > > 73s and thanks, > Dave > NK7Z > https://www.nk7z.net > >> On 07/17/2018 07:15 AM, turnbull wrote: >> I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. >> 73 DOUG EI2CN >> >> >> Sent from my Samsung Galaxy smartphone. >> -------- Original message --------From: Michael Blake via Elecraft <[hidden email]> Date: 17/07/2018 14:12 (GMT+00:00) To: Nr4c <[hidden email]> Cc: Elecraft Reflector <[hidden email]>, ANDY DURBIN <[hidden email]> Subject: Re: [Elecraft] KPA500 thermal clicks >> While possibly my imagination, after a few months of use I loosened all of the Z bracket to heatsink screws and side panel to heatsink screws and then retightened all of them plus the top cover to Z bracket screws. That seemed to reduce the clicking. >> >> Very 73 - Mike - K9JRI >> >> >> >> >>> On Jul 17, 2018, at 9:05 AM, Nr4c <[hidden email]> wrote: >>> >>> “Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. >>> >>> Sent from my iPhone >>> ...nr4c. bill >>> >>> >>>> On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: >>>> >>>> The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. >>>> >>>> >>>> In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. >>>> >>>> >>>> I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. >>>> >>>> >>>> I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? >>>> >>>> >>>> 73, >>>> >>>> Andy k3wyc >>>> ______________________________________________________________ >>>> 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] >> >> ______________________________________________________________ >> 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] >> > ______________________________________________________________ > 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] 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]
Chuck, KE9UW
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In reply to this post by Doug Turnbull
It is a "weak signal" mode [like WSPR], it will decode signals below the
noise in an SSB channel. It is not a "low power" mode. 73, Fred ["Skip"] K6DGW Sparks NV DM09dn Washoe County On 7/17/2018 7:15 AM, turnbull wrote: > I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. > 73 DOUG EI2CN > > > ______________________________________________________________ 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 Doug Turnbull
If you want to talk about weak signal vs low power please start another thread. Please don't take the discussion away from the topic I started.
In that new thread I'll be happy to tell you about my antenna, the signal reports I received, and the QSO I struggled to complete this morning. Andy k3wyc ______________________________________________________________ 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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Ok. I have a KPA500 and I never heard any clicks. I run about 400 Watts SSB with the fan always on #1 to start with but don’t recall hearing the fan speed up often.
Chuck Jack KE9UW Sent from my iPhone, cjack > On Jul 17, 2018, at 11:26 AM, ANDY DURBIN <[hidden email]> wrote: > > If you want to talk about weak signal vs low power please start another thread. Please don't take the discussion away from the topic I started. > > > In that new thread I'll be happy to tell you about my antenna, the signal reports I received, and the QSO I struggled to complete this morning. > > > Andy k3wyc > > > ______________________________________________________________ > 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]
Chuck, KE9UW
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In reply to this post by Doug Turnbull
No, FT-8 is a weak signal mode. That is not the same as a low power mode.
Bob, K4TAX Sent from my iPhone > On Jul 17, 2018, at 9:15 AM, turnbull <[hidden email]> wrote: > > I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. > 73 DOUG EI2CN > > > Sent from my Samsung Galaxy smartphone. > -------- Original message --------From: Michael Blake via Elecraft <[hidden email]> Date: 17/07/2018 14:12 (GMT+00:00) To: Nr4c <[hidden email]> Cc: Elecraft Reflector <[hidden email]>, ANDY DURBIN <[hidden email]> Subject: Re: [Elecraft] KPA500 thermal clicks > While possibly my imagination, after a few months of use I loosened all of the Z bracket to heatsink screws and side panel to heatsink screws and then retightened all of them plus the top cover to Z bracket screws. That seemed to reduce the clicking. > > Very 73 - Mike - K9JRI > > > > >> On Jul 17, 2018, at 9:05 AM, Nr4c <[hidden email]> wrote: >> >> “Clicks” caused by the “Z” bracket are well documented and normal. Personally, I don’t find this “intolerable” or even slightly annoying. My wall clock “ticks” every second. >> >> Sent from my iPhone >> ...nr4c. bill >> >> >>> On Jul 17, 2018, at 7:56 AM, ANDY DURBIN <[hidden email]> wrote: >>> >>> The clicking of my KPA500 is almost intolerable and I'd like to know if what I'm experiencing is typical. >>> >>> >>> In an FT8 TX/RX cycle with output power 126 W my KPA500 clicks 7-8 times during 15 second transmit and 7-8 times during 15 second receive. In these TX/RX cycles my logger shows the finals temperature swings between 57 deg C and 63 deg C. During this test the KPA500 was seeing an SWR of 1.02:1 and calculated PA dissipation was 307 W. >>> >>> >>> I don't think this temperature swing is likely to cause the heat sink to expand and contract significantly. The thermal mass of the heat sink is quite large and the heating and cooling periods are short. The first click happens almost as soon as the KPA500 is keyed. >>> >>> >>> I think it is possible that the clicks are caused by expansion and contraction of the finals at their mounting points. Is that likely and, if so, why would it be considered normal? >>> >>> >>> 73, >>> >>> Andy k3wyc >>> ______________________________________________________________ >>> 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] > > ______________________________________________________________ > 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] ______________________________________________________________ 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 Doug Turnbull
FT8 was designed for several applications. First, for double-hop E-skip
on 6M, where openings are often brief and not very strong. Second, for weak signal conditions, and conditions on any band where the path is noise-limited. This is generally true of ALL of the WSJT modes -- legal limit is often used on VHF for moon-bounce, meteor scatter, and tropo communications. Note that WEAK SIGNAL does NOT mean QRP. FT8 has signal to noise immunity that I would estimate as 6-10 dB better than excellent CW operators on both ends of the QSO. When used on the HF bands, fairly low TX power is generally enough. But when used on 6M and 160M, it's common to run whatever power is needed to make the QSO. I run my KPA500 at 500W on 6M, and I'm running a borrowed KPA1500 at 1.4 kW. I don't generally use FT8 on the HF bands, although I did to work KH1 last month. My experience on 6M has been that even though I'm running high power, my signal report, which is based on signal to noise at the other end, is usually 6-10 dB worse than the report that I send. Yesterday, for example, I failed to finish three 6M QSOs because the other station, who was reading -14 dB, couldn't copy me! Sadly, it has become increasingly common for us to have very high noise levels, resulting from switch-mode power supplies, solar power systems, variable-speed motor controllers, leaking from CATV systems, defective components on power lines, and a host of other sources. 73, Jim K9YC I thought FT8 was a low power mode. Am I wrong? I am not referring to Fox Hound mode. ______________________________________________________________ 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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