K3 External Reference input
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Is there interest among the group for the necessary parts to input a
disciplined 10MHz signal to control frequency? We all know there is a place holder on the back panel, but Gary just told me there were no plans. In April Wayne said it was coming but the price hadn't been set. Just wondering if anyone else out there has an interest like I do. 73, Phil K3(352)TUF _______________________________________________ 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: K3 External Reference input
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> Is there interest among the group for the necessary parts to input a
> disciplined 10MHz signal to control frequency? We all know there is a > place > holder on the back panel, but Gary just told me there were no plans. I'm really hoping for this option. I use a Hewlett-Packard 58540A GPSDO for use with my IC-7800. Long-term accuracy when GPS-locked is typically 1E-12. That's essentially the same accuracy as the atomic cesium beam standards used on board the GPS satellites. Most GPSDOs are not known for their ultra-high phase noise performance. Still, the SC-cut OCXOs as used in the HP Z3801A, HP Z3816A, and HP 58540A units are typically -145 dBc/Hz @ 1kHz offset. On the used market, expect to pay USD $300-$800. However, there is one relatively new, compact GPSDO from Jackson Labs that has hit the market and offers excellent phase noise performance for a GPSDO.: http://www.jackson-labs.com/docs/Fury_Flyer.pdf Even better phase noise performance (e.g., -165 dBc/Hz @ 1 kHz) can be had through the use of non-GPS-disciplined OCXOs. For example, Wenzel makes highly accurate OCXOs with phase noise specs that are typically 0-15 dB better than the GPSDO types. http://www.wenzel.com/pdffiles1/Oscillators/Comp.pdf With either of these types, one simply connects the output of the OCXO to the 10MHz reference input on the transceiver with one cable. The OCXO is powered from a low-voltage DC power source. Although the K3 may not be capable of resolving to 1E-12 accuracy, you can be rest assured that when using either of these oscillator types that your signal will be the new frequency standard on the bands. Paul, W9AC _______________________________________________ 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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I am too.
Back in April Wayne said: On Apr 29, 2007, at 3:20 AM, Bryan wrote: > Hi Wayne, > > If you use the external 10Mhz signal, does this mean that you don't > need the TCXO ? Even the standard K3 comes with a TCXO, so you'll always have one. The external reference option, when plugged in, will work with the TCXO. Note that the external reference module is not completed and may not be available at time of first shipments. But it'll be easy to install yourself once it arrives. Pricing hasn't been set. 73, Wayne N6KR Now that I have the K3 I'd like to connect it to my GPS Spectracom. 73, Phil K3(352)TUF -----Original Message----- From: Paul Christensen [mailto:[hidden email]] Sent: Friday, February 22, 2008 8:24 PM To: Philip Theis; [hidden email] Subject: Re: [Elecraft] K3 External Reference input > Is there interest among the group for the necessary parts to input a > disciplined 10MHz signal to control frequency? We all know there is a > place > holder on the back panel, but Gary just told me there were no plans. I'm really hoping for this option. I use a Hewlett-Packard 58540A GPSDO for use with my IC-7800. Long-term accuracy when GPS-locked is typically 1E-12. That's essentially the same accuracy as the atomic cesium beam standards used on board the GPS satellites. Most GPSDOs are not known for their ultra-high phase noise performance. Still, the SC-cut OCXOs as used in the HP Z3801A, HP Z3816A, and HP 58540A units are typically -145 dBc/Hz @ 1kHz offset. On the used market, expect to pay USD $300-$800. However, there is one relatively new, compact GPSDO from Jackson Labs that has hit the market and offers excellent phase noise performance for a GPSDO.: http://www.jackson-labs.com/docs/Fury_Flyer.pdf Even better phase noise performance (e.g., -165 dBc/Hz @ 1 kHz) can be had through the use of non-GPS-disciplined OCXOs. For example, Wenzel makes highly accurate OCXOs with phase noise specs that are typically 0-15 dB better than the GPSDO types. http://www.wenzel.com/pdffiles1/Oscillators/Comp.pdf With either of these types, one simply connects the output of the OCXO to the 10MHz reference input on the transceiver with one cable. The OCXO is powered from a low-voltage DC power source. Although the K3 may not be capable of resolving to 1E-12 accuracy, you can be rest assured that when using either of these oscillator types that your signal will be the new frequency standard on the bands. Paul, W9AC _______________________________________________ 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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> Now that I have the K3 I'd like to connect it to my GPS Spectracom.
I want to slave it to my shack GPSDO, too -- and will! Some other parts of the K3 system have a higher priority at present, but given time... 73, Lyle KK7P _______________________________________________ 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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That's great, just what I want to hear. Just so it's on the road map.
Didn't get that assurance from Gary. Thanks so much Lyle. We can wait for something good. 73, Phil K3(352)TUF ----- Original Message ----- From: "Lyle Johnson" <[hidden email]> To: "Philip Theis" <[hidden email]> Cc: "'Paul Christensen'" <[hidden email]>; <[hidden email]> Sent: Friday, February 22, 2008 9:52 PM Subject: Re: [Elecraft] K3 External Reference input >> Now that I have the K3 I'd like to connect it to my GPS Spectracom. > > I want to slave it to my shack GPSDO, too -- and will! Some other parts > of the K3 system have a higher priority at present, but given time... > > 73, > > Lyle KK7P > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. Version: 7.5.516 / Virus Database: > 269.20.9/1294 - Release Date: 2/22/2008 6:39 PM > _______________________________________________ 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: K3 External Reference input
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In reply to this post by P.B. Christensen
On Fri, 2008-02-22 at 20:24 -0500, Paul Christensen wrote: > > Is there interest among the group for the necessary parts to input a > > disciplined 10MHz signal to control frequency? We all know there is a > > place > > holder on the back panel, but Gary just told me there were no plans. > > I'm really hoping for this option. I use a Hewlett-Packard 58540A GPSDO for > use with my IC-7800. Long-term accuracy when GPS-locked is typically 1E-12. > That's essentially the same accuracy as the atomic cesium beam standards > used on board the GPS satellites. The 7800 has some decimation error issues and can be off from the standard by up to 0.1Hz A simple demo of this is to put main and sub RX on the same signal on the same antenna and listen in stereo for the slow phasing that goes on between the 2 receivers, it's horrid and makes it a very poor diversity receiver. It's due to the IF of the sub RX being separated by 100Khz this leads to a difference in the decimation errors between the main and Sub RX. Shame on Icom for getting this so wrong. I Don't know if decimation errors will limit the accuracy of the K3 when using an external ref but I would not be surprised if this was the case. Just because you can attach an external ref does not mean that your RX/TX is now as accurate as the reference, there are other factors that may limit overall system accuracy My Racal 3702 is on the other hand a true diversity receiver, both receivers are truly phase locked at all stages to any supplied reference, external or internal. It's a joy to use for diversity reception and true diversity reception is a fantastic tool for tropical band BC dxing One other issue is that the 7800 simply replaces it's internal oscillator with the external source so that external source needs to have excellent Phase noise performance if you are to avoid degrading the performance of the radio. This will be an even bigger issue with the K3 at narrow spacings. IF Elecraft get to market with the external ref port I'll probably be adding it. I have a collection of GPS locked oscillators, 2 of them are rubidium based I also have a home brew IPv6 stratum 1 NTP server at balrog.home.minish.org If you have IPv6 Internet connectivity try it out and let me know how you get on 73 Brendan EI6IZ -- Don‘t complain. Nobody will understand. Or care. And certainly don‘t try to fix the situation yourself. It‘s dangerous. Leave it to a highly untrained, unqualified, expendable professional. _______________________________________________ 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: K3 External Reference input
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In reply to this post by Phil K3TUF
You bet! That is one of the reasons I bought a K3. Jerry AI6L -----Original Message----- From: Philip Theis [mailto:[hidden email]] Sent: Friday, February 22, 2008 4:50 PM To: [hidden email] Subject: [Elecraft] K3 External Reference input Is there interest among the group for the necessary parts to input a disciplined 10MHz signal to control frequency? We all know there is a place holder on the back panel, but Gary just told me there were no plans. In April Wayne said it was coming but the price hadn't been set. Just wondering if anyone else out there has an interest like I do. 73, Phil K3(352)TUF _______________________________________________ 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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I wonder how Elecraft planned to implement the "External Synch Module."
Especially in light of the non-harmonic relationship of 10Mhz and 49.38Mhz. Would some recalibration and firmware changes be required? 73 jim ab3cv _______________________________________________ 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: K3 External Reference input
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In reply to this post by Brendan Minish
> The 7800 has some decimation error issues and can be off from the
> standard by up to 0.1Hz A simple demo of this is to put main and sub RX > on the same signal on > the same antenna and listen in stereo for the slow phasing that goes on > between the 2 receivers, it's horrid and makes it a very poor diversity > receiver. That's likely why Icom has yet refused to add auto Main/Sub tracking. OTOH, one of the first tests I conducted was to sync the 7800's Main and Sub receivers and sample the audio into an oscilloscope in X-Y mode to establish a Lissajous pattern. Any phase shift is represented by a change in the pattern from a straight line to a fuzzy line, then to what appears as a fuzzy ball. I could leave the 7800 running for days and not notice any phase shift unless I induced the phase shift (e.g., moving the sub Rx by 1 Hz, for example). Paul, W9AC _______________________________________________ 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 Phil K3TUF
Me too!
The external Ref is very important to my QRSS QRPp very weak signal work to maintain my frequency tolerance to less then .1 hz. I am currently using an HP 3325A Synthesizer and HP Z3801A GPS Ref to put a stable and accurate signal on the air! Also have my RX340 referenced to the Z3801A Not having the external reference opt is a big setback! I hope the ability to reduce the output power down to -15 dBm using the KXV3 is still possible? Larry Putman WB3ANQ Pasadena, Maryland FM19rc www.wb3anq.com ----- Original Message ---- From: Jerry T. Dowell <[hidden email]> To: Philip Theis <[hidden email]>; [hidden email] Sent: Saturday, February 23, 2008 9:17:39 AM Subject: RE: [Elecraft] K3 External Reference input You bet! That is one of the reasons I bought a K3. Jerry AI6L -----Original Message----- From: Philip Theis [mailto:[hidden email]] Sent: Friday, February 22, 2008 4:50 PM To: [hidden email] Subject: [Elecraft] K3 External Reference input Is there interest among the group for the necessary parts to input a disciplined 10MHz signal to control frequency? We all know there is a place holder on the back panel, but Gary just told me there were no plans. In April Wayne said it was coming but the price hadn't been set. Just wondering if anyone else out there has an interest like I do. 73, Phil K3(352)TUF ____________________________________________________________________________________ Never miss a thing. Make Yahoo your home page. http://www.yahoo.com/r/hs _______________________________________________ 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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