K2 KPA100 fan replacement?
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Hi Sverre,
I did have a look at this but discovered that the options for alternative 30mm fans are limited compared with larger sized case fans. There's no Noctua 30mmx10mm fan. The Evercool fan in the KPA100 runs at 8000rpm. I suspect these smaller fans are inherently noisier. The timbre of the sound they emit in full flight sounds harmonic rich and higher pitched, so it's more noticeable if you have well preserved high frequency auditory acuity :). I use my K2/100 for QRP only, because if I work CW at 20W or more, the fan runs pretty much continuously on Tx. 73, John VK7JB ______________________________________________________________ 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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Remember that there is an option on the KPA100 to have the fan run continuously at low speed. This keeps it cooler and cuts down on number of times it kicks into high gear. Still sounds like a 747 winding up for take-off in those instances, but it does help. Maybe a large, quiet, external muffin fan lying on top would add enough cooling to prevent it from running? 73 de dave ab9ca/4 On 8/23/14 6:31 AM, John Farmer wrote: > Hi Sverre, > > > > I did have a look at this but discovered that the options for alternative > 30mm fans are limited compared with larger sized case fans. There's no > Noctua 30mmx10mm fan. > > The Evercool fan in the KPA100 runs at 8000rpm. I suspect these smaller > fans are inherently noisier. The timbre of the sound they emit in full > flight sounds harmonic rich and higher pitched, so > > it's more noticeable if you have well preserved high frequency auditory > acuity :). I use my K2/100 for QRP only, because if I work CW at 20W or > more, the fan runs pretty much continuously on Tx. > > > > 73, > > John > > VK7JB > > > > > > > > > > ______________________________________________________________ > 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 VK7JB
John,
That is not normal. You might want to check a couple things. First, connect an external wattmeter and monitor the actual output - set the power control at 50 watts and see how much power you actually have on CW keydown. If it is much higher (greater than 100 watts), you have a problem with the KPA100 wattmeter. Continued operation with that condition present will cause your base K2 PA transistors to be stressed and will fail sometime soon. Even if you operate with the power knob set below 11 watts, the base K2 PA will still be stressed because the base PA is putting out the maximum power that it can develop - often exceeding 18 watts. Secondly, check the menu setting for CAL TPA - turn power off and wait at least 1/2 hour to allow things to cool to ambient. Then power on and check the setting of CAL TPA - adjust to the ambient temperature in degC if necessary. If you are doing CW (or data modes) with a high transmit to receive ratio, such as during a hot and heavy contest, you can set the fan to LO-HI so it will run at low speed all the time and keep things cooler - that means the times it switches to high speed will be reduced. In normal mode, the fan does not run until the CAL TPA temperature (and the heatsink if CAL TPA is properly calibrated) reaches 40 degC and will turn off when the temperature drops to 36 degC. 73, Don W3FPR On 8/23/2014 7:31 AM, John Farmer wrote: > it's more noticeable if you have well preserved high frequency auditory > acuity :). I use my K2/100 for QRP only, because if I work CW at 20W or > more, the fan runs pretty much continuously on Tx. > > > ______________________________________________________________ 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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Thanks Don. I appreciate the tips. The power and ambient temp calibrations check out OK. I'll try changing the fan setting and see what that does. I work only CW and once the rig gets up to the temperature threshold, after an over or two, the fan stays pretty busy thereafter. Leaving the fan on low between transmissions may do the trick.
Cheers, John VK7JB > On 23 Aug 2014, at 23:48, Don Wilhelm <[hidden email]> wrote: > > John, > > That is not normal. You might want to check a couple things. > First, connect an external wattmeter and monitor the actual output - set the power control at 50 watts and see how much power you actually have on CW keydown. > If it is much higher (greater than 100 watts), you have a problem with the KPA100 wattmeter. > Continued operation with that condition present will cause your base K2 PA transistors to be stressed and will fail sometime soon. Even if you operate with the power knob set below 11 watts, the base K2 PA will still be stressed because the base PA is putting out the maximum power that it can develop - often exceeding 18 watts. > > Secondly, check the menu setting for CAL TPA - turn power off and wait at least 1/2 hour to allow things to cool to ambient. Then power on and check the setting of CAL TPA - adjust to the ambient temperature in degC if necessary. > > If you are doing CW (or data modes) with a high transmit to receive ratio, such as during a hot and heavy contest, you can set the fan to LO-HI so it will run at low speed all the time and keep things cooler - that means the times it switches to high speed will be reduced. > > In normal mode, the fan does not run until the CAL TPA temperature (and the heatsink if CAL TPA is properly calibrated) reaches 40 degC and will turn off when the temperature drops to 36 degC. > > 73, > Don W3FPR > >> On 8/23/2014 7:31 AM, John Farmer wrote: >> it's more noticeable if you have well preserved high frequency auditory >> acuity :). I use my K2/100 for QRP only, because if I work CW at 20W or >> more, the fan runs pretty much continuously on Tx. > 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 VK7JB
when I cable the xg3 to the kx3, and set the mode to cw,normalize the
filters,and set the xg3 to -73 dbm.... I read a S-5 reading the S-meter. all per-band preamp settings are 20db - default (6m is 30db - default) I would expect a S9 reading. ______________________________________________________________ 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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Are you by chance tuning in to the opposite sideband signal? That would show weaker.
-----Original Message----- From: "Jeff Herr" <[hidden email]> Sent: Sunday, August 24, 2014 9:58am To: [hidden email] Subject: [Elecraft] KX3 XG3 when I cable the xg3 to the kx3, and set the mode to cw,normalize the filters,and set the xg3 to -73 dbm.... I read a S-5 reading the S-meter. all per-band preamp settings are 20db - default (6m is 30db - default) I would expect a S9 reading. ______________________________________________________________ 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 Jeff Herr
Jeff,
Re: when I cable the xg3 to the kx3, and set the mode to cw, normalize the filters, and set the xg3 to -73 dbm....I read a S-5 reading the S-meter…I would expect a S9 reading. Having a family get-together here, so haven't have a lot of time, but I sneaked away for a few minutes to see what mine read since I noted anomalies when I received my XG3 a couple of months ago. Here is what I found today with my KX3: Initially, with a -73dbm signal from my XG3, my KX3 read one segment (5db) over S9 (40m). Not too bad. Then I increased the XG3 output to -33 dbm, and the S-meter read 25db over S9. Returning the XG3 to -73 dbm gave an S-meter reading of S7 instead of the previous 5 over S9. I have seen this behavior in the past, but… I turned the radio and XG3 off for an hour and went back to it and checked the -73 dbm setting again and now I get S7 consistently. That surprised me, as I expected it to match the 5 over S9 I got the very first time I tried it. I cannot explain why I got 5db over S9 initially. I just tried the same thing on 80m and could not duplicate it there. No matter what I did there, I always got S9 with a -73dbm input. I will probably play with this some more when I get some time, but it is just a curiosity for me since I don’t use the s-meter all that often, and then only for relative readings to get a feel for what the band is doing, or for tuning signals. I don’t often care what the actual number is. Mark KE6BB So many variables between the transmitter and the S-meter, so little time. From: Jeff Herr Sent: Sunday, August 24, 2014 07:58 AM To: [hidden email] when I cable the xg3 to the kx3, and set the mode to cw,normalize the filters,and set the xg3 to -73 dbm.... I read a S-5 reading the S-meter. all per-band preamp settings are 20db - default (6m is 30db - default) I would expect a S9 reading. ______________________________________________________________ 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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