FW: K3 SWR Accuracy - reprise
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From: Jack Smith [mailto:[hidden email]] Sent: Sunday, November 08, 2009 10:00 PM To: Edward Dickinson, III Subject: Re: [Elecraft] K3 SWR Accuracy - reprise Dick: http://www.cliftonlaboratories.com/swr_accuracy.htm I posted a message to the Elecraft reflector about the page being available but it has not shown up after an hour and a half. Jack K8ZOA Edward Dickinson, III wrote: Hi Jack. I extend invitation to apply your expertise regarding the matter being addressed in above referenced discussion. Best regards, Dick - KA5KKT ______________________________________________________________ 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 |
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Great data, Jack. We've been testing this, too, and we know why the
K3's readings differ. A firmware change will be made to improve the accuracy in general. But part of the difference on the higher bands is due to strays in the KAT3 module. These strays can be tuned out by the KAT3 itself, thus presenting the correct load to the K3 internally. But an external instrument is on the other side of the KAT3 and thus sees a slightly different match. We'll post additional details soon. Meanwhile, no one need worry about this apparent discrepancy. The ATU is cancelling its own strays, and the SWR bridge is correctly reporting the load presented to the transceiver internally, which is the important thing when matching the rig to its load. 73, Wayne N6KR ---- http://www.elecraft.com On Nov 8, 2009, at 7:18 PM, "Edward Dickinson, III" <[hidden email] > wrote: > _____ > > From: Jack Smith [mailto:[hidden email]] > Sent: Sunday, November 08, 2009 10:00 PM > To: Edward Dickinson, III > Subject: Re: [Elecraft] K3 SWR Accuracy - reprise > > Dick: > > http://www.cliftonlaboratories.com/swr_accuracy.htm > > I posted a message to the Elecraft reflector about the page being > available > but it has not shown up after an hour and a half. > > Jack K8ZOA > > > Edward Dickinson, III wrote: > > Hi Jack. > > > > I extend invitation to apply your expertise regarding the matter being > > addressed in above referenced discussion. > > > > > > Best regards, > > > > Dick - KA5KKT > > > > > > > > > > ______________________________________________________________ > 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 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 |
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In reply to this post by Dick Dickinson
Wayne (and Jack) I and at least one other user, have noted the K3 with
ATU sometimes appears to leave a residual C or L in circuit on 10m when in "bypass" giving lower than expected power into a 50 Ohm load and may give incorrect TX power calibration as a result. Using the ATU to give a good SWR fixed the problem. The residual issue isn't always there, the typical false SWR is 1.5:1 or 1.6:1. 73 Dave, G4AON K3/100 #80 -------------- We'll post additional details soon. Meanwhile, no one need worry about this apparent discrepancy. The ATU is cancelling its own strays, and the SWR bridge is correctly reporting the load presented to the transceiver internally, which is the important thing when matching the rig to its load. 73, Wayne ______________________________________________________________ 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 |
Re: FW: K3 SWR Accuracy - reprise
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In reply to this post by Dick Dickinson
Dear Dick,
Thank you for the posting and thanks also to Jack for his thorough and professional analysis. Like Stewart I was interested to see the similarity between his findings and Jack's, and also my own on 40m as discussed on and off the reflector in May this year. 73 to all Geoff G3UCK ----- Original Message ----- From: "Edward Dickinson, III" <[hidden email]> Sent: Monday, November 09, 2009 3:18 AM ___ > > From: Jack Smith [mailto:[hidden email]] > Sent: Sunday, November 08, 2009 10:00 PM > To: Edward Dickinson, III > Subject: Re: [Elecraft] K3 SWR Accuracy - reprise > > Dick: > > http://www.cliftonlaboratories.com/swr_accuracy.htm > > I posted a message to the Elecraft reflector about the page being > available > but it has not shown up after an hour and a half. > > Jack K8ZOA ______________________________________________________________ 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 |
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In reply to this post by wayne burdick
Will the revision be generic to the extent that it will also improve the readings for radios without the KAT3? My variations are not as great as Jack's, I suspect due to not having the KAT3, but my readings are consistently lower than Jack's, ie. 1.6 on most bands with a 2.0 load. Not a big deal, but as long as you're in there tweaking the code, can you verify that it works with non-KAT3 radios as well?
73, Larry N8LP
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Re: K3 SWR Accuracy - reprise
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In reply to this post by wayne burdick
Speaking of the KAT3, Jack's report doesn't state whether or not his
K3 contains the KAT3 module or not, and what state it's in. Bob NW8L On Sun, Nov 8, 2009 at 9:07 PM, Wayne Burdick <[hidden email]> wrote: > Great data, Jack. We've been testing this, too, and we know why the > K3's readings differ. > > A firmware change will be made to improve the accuracy in general. But > part of the difference on the higher bands is due to strays in the > KAT3 module. These strays can be tuned out by the KAT3 itself, thus > presenting the correct load to the K3 internally. But an external > instrument is on the other side of the KAT3 and thus sees a slightly > different match. > > We'll post additional details soon. Meanwhile, no one need worry about > this apparent discrepancy. The ATU is cancelling its own strays, and > the SWR bridge is correctly reporting the load presented to the > transceiver internally, which is the important thing when matching the > rig to its load. > > 73, > Wayne > N6KR > > > ---- > http://www.elecraft.com > > On Nov 8, 2009, at 7:18 PM, "Edward Dickinson, III" <[hidden email] > > wrote: > >> _____ >> >> From: Jack Smith [mailto:[hidden email]] >> Sent: Sunday, November 08, 2009 10:00 PM >> To: Edward Dickinson, III >> Subject: Re: [Elecraft] K3 SWR Accuracy - reprise >> >> Dick: >> >> http://www.cliftonlaboratories.com/swr_accuracy.htm >> >> I posted a message to the Elecraft reflector about the page being >> available >> but it has not shown up after an hour and a half. >> >> Jack K8ZOA >> >> >> Edward Dickinson, III wrote: >> >> Hi Jack. >> >> >> >> I extend invitation to apply your expertise regarding the matter being >> >> addressed in above referenced discussion. >> >> >> >> >> >> Best regards, >> >> >> >> Dick - KA5KKT >> >> >> >> >> >> >> >> >> >> ______________________________________________________________ >> 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 > ______________________________________________________________ > 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 > 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 |
Re: K3 SWR Accuracy - reprise
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In reply to this post by N8LP
> consistently lower than Jack's, ie. 1.6 on most bands with a 2.0 load. Not
> a > big deal, but as long as you're in there tweaking the code, can you verify > that it works with non-KAT3 radios as well? I'm curious -- are those who see a smaller indicated VSWR reading on the K3 meter with a 25-ohm load seeing the same discrepancy with a 100-ohm load? This may partially explain why some owners are seeing varying results under a 2:1 VSWR since that ratio can be comprised of those two resistance loads or an infinite set of resistive + reactive conditions -- any of which can form a load impedance of 25 or 100 ohms. Paul, W9AC ______________________________________________________________ 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 |
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In reply to this post by Bob Cunnings NW8L
He does have the KAT3, and it was in bypass for the tests.
Larry N8LP
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In reply to this post by P.B. Christensen
That's a good question, Paul. I have a medium power, 150 ohm load laying around that I made up a couple years ago for testing purposes. I just checked it with my VNA and it has an SWR of 2.92, pure resistive. I did a quick test with the K3 at 25W, and it measured between 2.4 and 2.7 depending on band. That's about the same percentage error as the 25 ohm load, but it's impossible to know if the error is in the same direction. I would think that you could calculate the direction using the "tuned" L-network values of a KAT3, but I don't have one installed.
Larry N8LP
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K3 SWR Accuracy: Final explanation
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Administrator
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There are two sources of the reported SWR inaccuracies:
- An SWR calculation scalar that I'll be adjusting in firmware; this is what's causing a 2:1 SWR to read closer to 1.8:1 on some K3s. - The KAT3 itself, and to a much lesser degree, the KANT3, which is present if the ATU is not installed. Both modules have inherent stray reactance, part of which is due to the 8.2 MHz first-IF trap. These strays slightly alter the impedance seen by the K3's SWR bridge. Even when the scalar correction is applied, there will still be a small frequency-dependent variation in SWR reading between the K3's bridge and an external instrument. This has no impact on K3 operation. 73, Wayne N6KR ______________________________________________________________ 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 |
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In reply to this post by N8LP
______________________________________________________________ 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 |
Re: K3 SWR Accuracy: Final explanation
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In reply to this post by wayne burdick
Wayne:
There's also an SWR versus output power issue, or is that part of the first correction factor? The SWR error increases significantly at lower power. I have not had a chance to plot the data because it was not part of the original question, but there is a clear power related error seen in the raw data, which I assume is tied to the detector diode linearity at low voltages. Jack K8ZOA Wayne Burdick wrote: > There are two sources of the reported SWR inaccuracies: > > - An SWR calculation scalar that I'll be adjusting in firmware; this > is what's causing a 2:1 SWR to read closer to 1.8:1 on some K3s. > > - The KAT3 itself, and to a much lesser degree, the KANT3, which is > present if the ATU is not installed. Both modules have inherent stray > reactance, part of which is due to the 8.2 MHz first-IF trap. These > strays slightly alter the impedance seen by the K3's SWR bridge. > > Even when the scalar correction is applied, there will still be a > small frequency-dependent variation in SWR reading between the K3's > bridge and an external instrument. This has no impact on K3 operation. > > 73, > Wayne > N6KR > > > ______________________________________________________________ > 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 > > 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 |
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In reply to this post by N8LP
I'm running tests today with the 25 ohm load connected to the K3/LP-100
with varying lengths of RG-142B/U coaxial cable, in 24 inch increments out to 120 or 144 inches. The result should be a constant SWR, neglecting the padding effect of coaxial cable loss, but with the impedance varying along the constant SWR circle if we think in Smith chart terms. I will also measure the R+jX of the load under the same conditions, with both the LP-100 and a VNA. I may have the data analyzed this evening, but more likely tomorrow. Also added a note confirming that my K3 has the KAT3 tuner, set to BYPASS for the tests. Jack N8LP wrote: > That's a good question, Paul. I have a medium power, 150 ohm load laying > around that I made up a couple years ago for testing purposes. I just > checked it with my VNA and it has an SWR of 2.92, pure resistive. I did a > quick test with the K3 at 25W, and it measured between 2.4 and 2.7 depending > on band. That's about the same percentage error as the 25 ohm load, but it's > impossible to know if the error is in the same direction. I would think that > you could calculate the direction using the "tuned" L-network values of a > KAT3, but I don't have one installed. > > Larry N8LP > > > > P.B. Christensen wrote: > >>> consistently lower than Jack's, ie. 1.6 on most bands with a 2.0 load. >>> Not >>> a >>> big deal, but as long as you're in there tweaking the code, can you >>> verify >>> that it works with non-KAT3 radios as well? >>> >> I'm curious -- are those who see a smaller indicated VSWR reading on the >> K3 >> meter with a 25-ohm load seeing the same discrepancy with a 100-ohm load? >> This may partially explain why some owners are seeing varying results >> under >> a 2:1 VSWR since that ratio can be comprised of those two resistance loads >> or an infinite set of resistive + reactive conditions -- any of which can >> form a load impedance of 25 or 100 ohms. >> >> Paul, W9AC >> >> ______________________________________________________________ >> 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 >> >> >> > > 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 |
Re: K3 SWR Accuracy: Final explanation
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In reply to this post by Jack Smith-6
There's no way to avoid some increase in SWR reading error at low
power, since the bridge transformers have a low coupling ratio to avoid heating at full power. We're already using very low-drop diodes and pre-biasing them. That said, I am going to look at a correction based on power level if possible. tnx Wayne N6KR On Nov 9, 2009, at 9:06 AM, Jack Smith wrote: > Wayne: > > There's also an SWR versus output power issue, or is that part of > the first correction factor? The SWR error increases significantly > at lower power. I have not had a chance to plot the data because it > was not part of the original question, but there is a clear power > related error seen in the raw data, which I assume is tied to the > detector diode linearity at low voltages. > > Jack K8ZOA > > > Wayne Burdick wrote: >> There are two sources of the reported SWR inaccuracies: >> >> - An SWR calculation scalar that I'll be adjusting in firmware; >> this is what's causing a 2:1 SWR to read closer to 1.8:1 on some >> K3s. >> >> - The KAT3 itself, and to a much lesser degree, the KANT3, which >> is present if the ATU is not installed. Both modules have inherent >> stray reactance, part of which is due to the 8.2 MHz first-IF >> trap. These strays slightly alter the impedance seen by the K3's >> SWR bridge. >> >> Even when the scalar correction is applied, there will still be a >> small frequency-dependent variation in SWR reading between the >> K3's bridge and an external instrument. This has no impact on K3 >> operation. >> >> 73, >> Wayne >> N6KR >> >> >> ______________________________________________________________ >> 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 >> >> ______________________________________________________________ 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 |
Re: K3 SWR Accuracy: Final explanation
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Does part of the K3 spec mention that it's supposed to be a precision
swr indicator? If so, I missed that. I thought that I was merely getting an outstanding transceiver, especially for cw, at a relatively low cost. This year, I became active on ham radio after a multi-decade hiatus. Before I left, the normal assumption about swr meters with diodes was that they had reduced accuracy at low power levels because of diode non-linearities. Has this changed while I was away? 73, Dunc, W5DC Wayne Burdick wrote: > There's no way to avoid some increase in SWR reading error at low > power, since the bridge transformers have a low coupling ratio to > avoid heating at full power. We're already using very low-drop diodes > and pre-biasing them. > > That said, I am going to look at a correction based on power level if > possible. > > tnx > Wayne > N6KR > > On Nov 9, 2009, at 9:06 AM, Jack Smith wrote: > > >> Wayne: >> >> There's also an SWR versus output power issue, or is that part of >> the first correction factor? The SWR error increases significantly >> at lower power. I have not had a chance to plot the data because it >> was not part of the original question, but there is a clear power >> related error seen in the raw data, which I assume is tied to the >> detector diode linearity at low voltages. >> >> Jack K8ZOA >> >> >> Wayne Burdick wrote: >> >>> There are two sources of the reported SWR inaccuracies: >>> >>> - An SWR calculation scalar that I'll be adjusting in firmware; >>> this is what's causing a 2:1 SWR to read closer to 1.8:1 on some >>> K3s. >>> >>> - The KAT3 itself, and to a much lesser degree, the KANT3, which >>> is present if the ATU is not installed. Both modules have inherent >>> stray reactance, part of which is due to the 8.2 MHz first-IF >>> trap. These strays slightly alter the impedance seen by the K3's >>> SWR bridge. >>> >>> Even when the scalar correction is applied, there will still be a >>> small frequency-dependent variation in SWR reading between the >>> K3's bridge and an external instrument. This has no impact on K3 >>> operation. >>> >>> 73, >>> Wayne >>> N6KR >>> >>> >>> ______________________________________________________________ >>> 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 >>> >>> >>> > > ______________________________________________________________ > 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 > > ______________________________________________________________ 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 |
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...Does part of the K3 spec mention that it's supposed to be a precision swr indicator?... 73, Dunc, W5DC ____________________________________ I am shocked and dismayed that the SWR indicator in the K3 does not, after all, rival an external, laboratory-grade instrument. This is a tremendously disturbing disappointment for me. In this state of dejection and disillusionment, and hoping to assuage my sorrow, I set out to verify some of the other controls on the K3 that I had assumed would be absolutely accurate. To my horror, I must now report -- with extreme reluctance-- that the CW speed control under-reports the CW speed by 2 WPM! How can this be? Wayne, I demand an immediate explanation. That was bad enough, but that's not all. To add seeming insult to injury, I have now found that when my CW pitch is set to 600 Hz the actual measured pitch is closer to 608 Hz. Instead of a D, it's more like an E-flat. Certainly, none of us is going to stand for that. If these two conditions are not corrected in the next release I'm going back to my Kensucom MarkTwoDoublePlusGee. I really thought that the K3 was a perfect rig in a perfect world, but I am utterly crushed to find that it is a merely great one in an imperfect world. Darn. W6LX said that. ______________________________________________________________ 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 |
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Al,
Here's another complaint. It seems the Elecraft refelector is stripping the .<dripping with (welldeserved) sarcasm> tag from your post just like it did the same to my last post. On the other hand, my audio spectrum analyzer reports the cw pitch as 600 Hz; I use it routinely because I like it better than Elecraft's CWT. I do still have my FT-101E in reserve if the K3 faults become too much to tolerate. 73, Dunc, W5DC Al Lorona wrote: > ____________________________________ > ...Does part of the K3 spec mention that it's supposed to be a precision > swr indicator?... > > 73, Dunc, W5DC > ____________________________________ > > I am shocked and dismayed that the SWR indicator in the K3 does not, after all, rival an external, laboratory-grade instrument. This is a tremendously disturbing disappointment for me. > > In this state of dejection and disillusionment, and hoping to assuage my sorrow, I set out to verify some of the other controls on the K3 that I had assumed would be absolutely accurate. > > To my horror, I must now report -- with extreme reluctance-- that the CW speed control under-reports the CW speed by 2 WPM! How can this be? Wayne, I demand an immediate explanation. > > That was bad enough, but that's not all. To add seeming insult to injury, I have now found that when my CW pitch is set to 600 Hz the actual measured pitch is closer to 608 Hz. Instead of a D, it's more like an E-flat. Certainly, none of us is going to stand for that. > > If these two conditions are not corrected in the next release I'm going back to my Kensucom MarkTwoDoublePlusGee. > > I really thought that the K3 was a perfect rig in a perfect world, but I am utterly crushed to find that it is a merely great one in an imperfect world. Darn. > > W6LX said that. > ______________________________________________________________ > 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 > > ______________________________________________________________ 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 |
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Duncan,
AND, *my* K3 gets dust on the plastic covering the LCD display. I really don't know why this has not been corrected by adding a sprayer and wipers to keep it clean. After all, every auto in the US has such a device, it should not be difficult to add on the K3 as well to assure a clean display. If the K3 is to be perfect, it should keep itself perfectly clean too. 73, Don W3FPR Duncan Carter wrote: > Al, > Here's another complaint. It seems the Elecraft refelector is stripping > the .<dripping with (welldeserved) sarcasm> tag from your post just like > it did the same to my last post. On the other hand, my audio spectrum > analyzer reports the cw pitch as 600 Hz; I use it routinely because I > like it better than Elecraft's CWT. > > I do still have my FT-101E in reserve if the K3 faults become too much > to tolerate. > > 73, Dunc, W5DC > > Al Lorona wrote: > >> ____________________________________ >> ...Does part of the K3 spec mention that it's supposed to be a precision >> swr indicator?... >> >> 73, Dunc, W5DC >> ____________________________________ >> >> I am shocked and dismayed that the SWR indicator in the K3 does not, after all, rival an external, laboratory-grade instrument. This is a tremendously disturbing disappointment for me. >> >> > 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 |
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On Nov 9, 2009, at 9:01 PM, Don Wilhelm wrote:
> If the K3 is to be perfect, it should keep itself perfectly clean too. Hey, I'll take it to the ridiculous limit of this line of humor: shouldn't the chassis have an ever-so-slight positive charge to actively repel dust? Ala the "sensor cleaners" in high end SLRS? By the time I've built my way through the K1 and K2, I will expect such perfection! Heh. 73, Byron KI6NUL ______________________________________________________________ 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 |
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