Re: [Elecraft] Cheap ref osc to lock K3
I bought a module like that. If you set the output frequency to something that divides evenly into 48MHz, then the output is quite stable. Otherwise, if you set it to something else like 10MHz, the jitter is quite obvious on the scope. It is fine for jobs like calibrating a frequency counter or zero-beating a transceiver. You'd probably want to smooth out the jitter though if you want to use it for a K3 reference oscillator. 73, Matt VK2RQ Envoyé à partir d'Outlook On Sat, Oct 3, 2015 at 8:19 AM -0700, "brian"wrote: LA3ZA used a UBLOX NEO-7 GPS unit to lock his K3. This $20 unit including complete development board can be obtained here. http://www.ebay.co.uk/itm/301199083821 It's tiny, has a patch antenna (although a $10 active antenna works better) and consumes under 60ma. It can be powered from +5v or a USB port. It fits in a 2"x3" box. Once set up it is stand alone not requiring a computer connection. There was some question as to whether the jitter of the unit would disqualify it as a decent ref osc. A posting on the SpectrumLab group indicated that it seems quite adequate for K3 disciplining. spectrumlabus...@yahoogroups.com Accuracy within 0.02 to 0.03 Hz of a Rb standard. Output spectrum seems to indicate that jitter is not a problem for this purpose. 73 de Brian/K3KO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to matt.vk...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Cheap ref osc to lock K3
My experience is that the simple GPS-based 10 MHz reference works well with the K3. The K3 is quoted as measuring frequency to 1 Hz accuracy, implying a measurement time of the order of 1 second. That seems to be enough to smooth out the jitter from the Neo-7M. Of course, there are better solutions around, but why spend money on something which is unnecessary? My experience including build instructions was posted on my blog yesterday: http://la3za.blogspot.no/2015/10/just-good-enough-10-mhz-reference.html vk2rq wrote > I bought a module like that. If you set the output frequency to something > that divides evenly into 48MHz, then the output is quite stable. > Otherwise, if you set it to something else like 10MHz, the jitter is quite > obvious on the scope. It is fine for jobs like calibrating a frequency > counter or zero-beating a transceiver. You'd probably want to smooth out > the jitter though if you want to use it for a K3 reference oscillator. > 73, Matt VK2RQ - Sverre, LA3ZA K2 #2198, K3 #3391, LA3ZA Blog: http://la3za.blogspot.com, LA3ZA Unofficial Guide to K2 modifications: http://la3za.blogspot.com/p/la3za-unofficial-guide-to-elecraft-k2.html -- View this message in context: http://elecraft.365791.n2.nabble.com/Cheap-ref-osc-to-lock-K3-tp7608667p7608700.html Sent from the Elecraft mailing list archive at Nabble.com. __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
Re: [Elecraft] Cheap ref osc to lock K3
I just bought this GPS for providing accurate time to my computer: ProGin GPS RECEIVER BU-353 (USB) SiRF STAR III ebay: 181887610445 Cost me $24 and change including shipping (from Israel). This is my replacement for Dimension-4 when I pull the internet plug on my XP computer and switch to my laptop for e-mail/internet using win-10. I will then be able to run the XP computer for my ham applications forever without worrying about security sw, upgrading drivers, etc.etc. 73, Ed - KL7UW I'll have to check if it supports frequency reference; But I run a OCXO for that so not needed. From: Matt Maguire <matt.vk...@gmail.com> To: brian <als...@nc.rr.com>, <elecraft@mailman.qth.net> Subject: Re: [Elecraft] Cheap ref osc to lock K3 Message-ID: <f0e8602df208aaee.1d8b3c8d-2dd6-4846-a44b-d2cf0774c...@mail.outlook.com> Content-Type: text/plain; charset=UTF-8 I bought a module like that. If you set the output frequency to something that divides evenly into 48MHz, then the output is quite stable. Otherwise, if you set it to something else like 10MHz, the jitter is quite obvious on the scope. It is fine for jobs like calibrating a frequency counter or zero-beating a transceiver. You'd probably want to smooth out the jitter though if you want to use it for a K3 reference oscillator. 73, Matt VK2RQ 73, Ed - KL7UW http://www.kl7uw.com "Kits made by KL7UW" Dubus Mag business: dubus...@gmail.com __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com
[Elecraft] Cheap ref osc to lock K3
LA3ZA used a UBLOX NEO-7 GPS unit to lock his K3. This $20 unit including complete development board can be obtained here. http://www.ebay.co.uk/itm/301199083821 It's tiny, has a patch antenna (although a $10 active antenna works better) and consumes under 60ma. It can be powered from +5v or a USB port. It fits in a 2"x3" box. Once set up it is stand alone not requiring a computer connection. There was some question as to whether the jitter of the unit would disqualify it as a decent ref osc. A posting on the SpectrumLab group indicated that it seems quite adequate for K3 disciplining. spectrumlabus...@yahoogroups.com Accuracy within 0.02 to 0.03 Hz of a Rb standard. Output spectrum seems to indicate that jitter is not a problem for this purpose. 73 de Brian/K3KO __ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:Elecraft@mailman.qth.net This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html Message delivered to arch...@mail-archive.com