K3 Reference Oscillator
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What is the operating frequency of the K3 TCXO reference oscillator?
Ron Durie [hidden email] www.duries.com/DurieElectronics.htm _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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49.380 MHz. All signal sources are phase-locked to the refernce. Fine
adjustment occurs in firmware, and once calibrated, it's accurate to about 1 Hz through 6 meters at the calibration temperature. The high-stability option is at the same frequency, with firmware correction to better than 0.5 ppm. 73, Wayne N6KR On Aug 29, 2007, at 8:51 AM, Ron Durie wrote: > What is the operating frequency of the K3 TCXO reference oscillator? > --- http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Wayne, given that 49.380 isn't a readily available
calibration freq like, say, WWV, how does a ham in the field check or set it if needed? 73, Bob N6WG ----- Original Message ----- From: "wayne burdick" <[hidden email]> To: "Ron Durie" <[hidden email]> Cc: <[hidden email]> Sent: Wednesday, August 29, 2007 8:59 AM Subject: [Elecraft] Re: K3 Reference Oscillator > 49.380 MHz. All signal sources are phase-locked to the refernce. Fine > adjustment occurs in firmware, and once calibrated, it's accurate to > about 1 Hz through 6 meters at the calibration temperature. The > high-stability option is at the same frequency, with firmware > correction to better than 0.5 ppm. > > 73, > Wayne > N6KR > > On Aug 29, 2007, at 8:51 AM, Ron Durie wrote: > > > What is the operating frequency of the K3 TCXO reference oscillator? > > > > > --- > > http://www.elecraft.com > > _______________________________________________ > Elecraft mailing list > Post to: [hidden email] > You must be a subscriber to post to the list. > Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > > Help: http://mailman.qth.net/subscribers.htm > Elecraft web page: http://www.elecraft.com Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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Hi Bob,
You can tune in a reference signal of your choice and adjust the REF CAL menu entry in real-time. You can even turn SPOT on while in the menu entry, then tune for zero beat. Works very well. 73, Wayne N6KR On Aug 29, 2007, at 9:04 AM, Robert Tellefsen wrote: > Wayne, given that 49.380 isn't a readily available > calibration freq like, say, WWV, how does a ham > in the field check or set it if needed? > 73, Bob N6WG --- http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by wayne burdick
At 11:59 AM 8/29/2007, wayne burdick wrote...
>49.380 MHz. All signal sources are phase-locked to the refernce. Fine >adjustment occurs in firmware, and once calibrated, it's accurate to >about 1 Hz through 6 meters at the calibration temperature. The >high-stability option is at the same frequency, with firmware >correction to better than 0.5 ppm. 49,380,000 * 0.0000005 ppm = 24.69 Hz, and actually worse on 6 meters, since it's a higher frequency. In any case, it's considerably worse that the 1 Hz stated for the standard reference. Is that ppm/degree C, over some temperature range, or ? Is the tempco specified for the standard reference? _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Re: K3 Reference Oscillator
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In reply to this post by n6wg
Bob:
REALLY SIMPLE! Go to CW mode, go to the highest WWV freq. you can hear, turn SPOT on and then crank on the REF CAL menu value until you hear dead zero beat. Tom At 11:04 08/29/2007, you wrote: >Wayne, given that 49.380 isn't a readily available >calibration freq like, say, WWV, how does a ham >in the field check or set it if needed? >73, Bob N6WG > >----- Original Message ----- >From: "wayne burdick" <[hidden email]> >To: "Ron Durie" <[hidden email]> >Cc: <[hidden email]> >Sent: Wednesday, August 29, 2007 8:59 AM >Subject: [Elecraft] Re: K3 Reference Oscillator > > > > 49.380 MHz. All signal sources are phase-locked to the refernce. Fine > > adjustment occurs in firmware, and once calibrated, it's accurate to > > about 1 Hz through 6 meters at the calibration temperature. The > > high-stability option is at the same frequency, with firmware > > correction to better than 0.5 ppm. > > > > 73, > > Wayne > > N6KR > > > > On Aug 29, 2007, at 8:51 AM, Ron Durie wrote: > > > > > What is the operating frequency of the K3 TCXO reference oscillator? > > > > > > > > > --- > > > > http://www.elecraft.com > > > > _______________________________________________ > > Elecraft mailing list > > Post to: [hidden email] > > You must be a subscriber to post to the list. > > Subscriber Info (Addr. Change, sub, unsub etc.): > > http://mailman.qth.net/mailman/listinfo/elecraft > > > > Help: http://mailman.qth.net/subscribers.htm > > Elecraft web page: http://www.elecraft.com >_______________________________________________ >Elecraft mailing list >Post to: [hidden email] >You must be a subscriber to post to the list. >Subscriber Info (Addr. Change, sub, unsub etc.): > http://mailman.qth.net/mailman/listinfo/elecraft > >Help: http://mailman.qth.net/subscribers.htm >Elecraft web page: http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by wayne burdick
Oooooh, way cool. Neat trick.
That should work like a charm. Thanks, Wayne. 73, Bob N6WG ----- Original Message ----- From: "wayne burdick" <[hidden email]> To: "Robert Tellefsen" <[hidden email]> Cc: <[hidden email]>; "Ron Durie" <[hidden email]> Sent: Wednesday, August 29, 2007 9:08 AM Subject: Re: K3 Reference Oscillator > Hi Bob, > > You can tune in a reference signal of your choice and adjust the REF > CAL menu entry in real-time. You can even turn SPOT on while in the > menu entry, then tune for zero beat. Works very well. > > 73, > Wayne > N6KR > > > On Aug 29, 2007, at 9:04 AM, Robert Tellefsen wrote: > > > Wayne, given that 49.380 isn't a readily available > > calibration freq like, say, WWV, how does a ham > > in the field check or set it if needed? > > 73, Bob N6WG > > > --- > > http://www.elecraft.com > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Mike S-8
Mike,
Maybe I wasn't clear on this. I said it was "accurate to 1 Hz ... at the calibration temperature." That says nothing about what happens as the temperature *changes*. +/- 0.5 ppm (or +/- 1 PPM) is the most common high-stability reference option available for ham transceivers, K3 included. (And yes, this applies to the entire temperature range, not per degree C.) The K3 has an advantage over most transceivers in this regard. The REF CAL menu entry can be used to enter frequency-vs.-temp data that's supplied with each individual 1 PPM oscillator. This data is used in conjunction with an accurate temperature sensor to fine-tune the reference in 0.2-Hz steps as the temperature changes. So we're actually expecting something like +/- 0.2 ppm over temperature. But we're specifying it conservatively. 73, Wayne N6KR On Aug 29, 2007, at 9:29 AM, Mike S wrote: > At 11:59 AM 8/29/2007, wayne burdick wrote... >> 49.380 MHz. All signal sources are phase-locked to the refernce. Fine >> adjustment occurs in firmware, and once calibrated, it's accurate to >> about 1 Hz through 6 meters at the calibration temperature. The >> high-stability option is at the same frequency, with firmware >> correction to better than 0.5 ppm. > > 49,380,000 * 0.0000005 ppm = 24.69 Hz, and actually worse on 6 meters, > since it's a higher frequency. In any case, it's considerably worse > that the 1 Hz stated for the standard reference. Is that ppm/degree C, > over some temperature range, or ? Is the tempco specified for the > standard reference? > > --- http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by Ron Durie SIL.org
0.5 parts per million stability is the same specification as most HF/VHF
rigs fitted with an optional TCXO. That equates to an error of +/- 25 Hz at 50 MHz. Higher stability can always be obtained at higher cost with an oven controlled oscillator. There is always the option of an external reference oscillator for those who aren't happy with a TCXO. I have a rubidium standard in the shack that was 1 part in 10^11 high in frequency a couple of days ago, relative to a GPS controlled standard alongside it... Yet I still have a KTCXO3-1 on order for my K3 - and will be quite satisfied with 0.5 ppm. A resolution to 1 Hz doesn't mean the K3 is capable of being set to an accuracy of 1 Hz at 50 MHz. 73 Dave, G4AON _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by wayne burdick
At 12:48 PM 8/29/2007, wayne burdick wrote...
>Maybe I wasn't clear on this. I said it was "accurate to 1 Hz ... at >the calibration temperature." That says nothing about what happens as >the temperature *changes*. > >[high stability] +/- 0.5 ppm ... applies to the entire temperature >range, not per degree C. > >The REF CAL menu entry can be used to enter frequency-vs.-temp data >that's supplied with each individual 1 PPM oscillator. This data is >used in conjunction with an accurate temperature sensor to fine-tune >the reference in 0.2-Hz steps as the temperature changes. Can the high stability reference also be calibrated at temperature to achieve 1 Hz, like the standard reference, or must one trust the calibration table which provides 0.2-0.5 ppm (10-25 Hz) accuracy? If calibrated at temperature, does the delta then offset other table entries (which might be used to accommodate crystal aging, for example), or are individual table entries calibrated? Can a calibration table be used with the standard reference? I can see some applications where "1 Hz, but you have to calibrate if the temp changes" is better than "10-25 Hz, but you never touch it." _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by wayne burdick
I've often wondered what the purpose of optional high stability
reference oscillators in HF rigs is. A couple hertz between friends on CW, SSB, or AM isn't noticeable. Even PSK can handle slow drift quite well. Is there some other mystery mode or application that requires the rubidium oscillator-like stability people seem to spend money on and crave? (Folks using transverters on microwave bands??) -- Blog: http://thek3ngreport.blogspot.com/ _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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In reply to this post by wayne burdick
On Aug 29, 2007, at 10:16 AM, Mike S wrote: > At 12:48 PM 8/29/2007, wayne burdick wrote... >> Maybe I wasn't clear on this. I said it was "accurate to 1 Hz ... at >> the calibration temperature." That says nothing about what happens as >> the temperature *changes*. >> >> +/- 0.5 ppm (or +/- 1 PPM) is the most common high-stability >> reference option available for ham transceivers, K3 included. (And >> yes, this applies to the entire temperature range, not per degree C.) >> >> The K3 has an advantage over most transceivers in this regard. The >> REF CAL menu entry can be used to enter frequency-vs.-temp data >> that's supplied with each individual 1 PPM oscillator. This data is >> used in conjunction with an accurate temperature sensor to fine-tune >> the reference in 0.2-Hz steps as the temperature changes. So we're >> actually expecting something like +/- 0.2 ppm over temperature. But >> we're specifying it conservatively. > > I assume then that the high-stability option can also be calibrated to > achieve 1 Hz through 6 meters at the calibration temperature, too > (that was not stated)? You can achieve 1-Hz accuracy at the calibration temperature with either the standard or high-stability TCXO. The REF CAL menu entry can also be used to enter Freq-vs.-Temp data with either one, but this data is only provided for the high-stability unit. One could enter data for the standard oscillator, too, but you'd have to determine what data to enter by manually calibrating to a reference signal at each temperature point (5 degree increments). So you could set the high-temp CAL points on hot days and the low-temp CAL points on cold days. I'm not sure what overall temperature stability you could achieve using this method with the standard unit, but we'll be trying it at some point. Meanwhile, if you really want the best stability over temperature, I'd recommend the high-stability unit plus entering the data as supplied. > > Can the standard reference use a calibration table, so it might become > more accurate as it is hand calibrated at different temperatures? Exactly -- see above. The manual will describe how to do this. 73, Wayne N6KR --- http://www.elecraft.com _______________________________________________ Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
Re: Re: K3 Reference Oscillator
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In reply to this post by Mike S-8
Mike,
I believe you are mixing parameters. The K3 can be set to within 1 Hz, but the 0.5 ppm number applies the drift with temperature changes, and that is something quite different than accuracy. 73, Don W3FPR Mike S wrote: > > Can the high stability reference also be calibrated at temperature to > achieve 1 Hz, like the standard reference, or must one trust the > calibration table which provides 0.2-0.5 ppm (10-25 Hz) accuracy? If > calibrated at temperature, does the delta then offset other table > entries (which might be used to accommodate crystal aging, for > example), or are individual table entries calibrated? Can a > calibration table be used with the standard reference? > > I can see some applications where "1 Hz, but you have to calibrate if > the temp changes" is better than "10-25 Hz, but you never touch it." > Elecraft mailing list Post to: [hidden email] You must be a subscriber to post to the list. Subscriber Info (Addr. Change, sub, unsub etc.): http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/subscribers.htm Elecraft web page: http://www.elecraft.com |
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