Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
In holdover mode (e.g., no antenna connected), accuracy is typically 7x10^-10 for the Thunderbolt. So, still quite good. However, I don't recall if the typical holdover specs require that the GPS-DO first initially attain lock, then the antenna can be removed. Paul, W9AC - Original Message - From: "Phil Kane" To: "Paul Christensen" Sent: Tuesday, June 21, 2011 11:30 AM Subject: Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3? > On 6/21/2011 6:49 AM, Paul Christensen wrote: > >> Locking the GPS-DO is as easy as throwing a tiny >> GPS antenna out the window. > > True, but I was referring to applications where the standard is > used as a "stand alone" device. My present comm room has > little or no GPS or WWVB access because it is 3/4 underground. > Were I to re-install it, I probably would have added a 14th > antenna to the roof for GPS :-) > > That's what happens when one's experience was in the pre-GPS > era.. > > -- 73 de K2ASP - Phil Kane >Elecraft K2/100 s/n 5402 > __ 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
Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
I dont know how much accuracy you need, but if no more than 1 ppm or so, find a Leader 823s frequency counter (S model is 1 ppm) cheap on ebay. Its internal clock is 10 mHz and it will put that signal out via a back panel BNC. You can zero beat it to WWV first to get it within a few Hertz or better. Mine holds to much better than .5 ppm. Other counters may have the same, I dont kniw, but this works for me. On Monday, June 20, 2011, David and Dianne on Comcast wrote: > Hi Everyone, > > I am considering a K3EXREF just for fun, no other > reason. > > Looking for suggestions for a reasonably priced 10 > MHz external signal source. > > Can anyone offer some suggestions? GPSDO? OCXO? > Rubidium Standard? > > I have seen some used Trimble Thunderbolt GPSDO's > on eBay form China. I'm just not sure about the > wisdom of ordering any of these units. > > Suggestions would be appreciated on or off the list. > > 73 de N1LQ-Dave > > __ > 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 > __ 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
Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
Long term stability is in the 10^10 range, and short term one sees <100 ppt generally. Quite often it's stable for minutes down to 25 ppt. The Thunderbolt is subject to GPS sats coming and going, and/or noise from sats being too near the horizon. Each time a sat joins or leaves the constellation, there is a little "few ppt" bounce in the ppt. I did some lab measurements against our Rb sources here at Magellan. It takes special test equipment that we don't have to be able to sense the difference. However, using a TIA locked to the GPSDO, the Rb drifts in relation to the tune of +/- 50 ppt for a short term observation. I don't have time to run it for months, just hours at a time. There will always be some question about the value of accurate frequency sources used with ham radio. The K3 VFO has its own finite resolution of 1 Hz, so that's the best quanta it can do anyway. Watching the compensation using REF CAL, I can see it drift up from 49379.690 to 49379.776 over the span of several hours. But that's just the compensation working against the TCXO and there is little or no difference in pitch on air air for fixed sources like WWV or CHU. There is no discernable beat note, since the heterodyne is below audible frequencies. I don't see it on the s-meter either, so it's probably around or below 1 Hz most of the time. The K3 makes very fine adjustments using the source, only on RX I believe, and only every few seconds. The K144XV ref lock is still tied to the TCXO , not the external reference. Dunno what the plan is to change this, but the TCXO-1 is so much better than the xx PPM crystal injection oscillators at 116 and 118 MHz that it's remarkable. Maybe not yet good enough for microwave work, but much better on 2m. 73, matt W6NIA On Tue, 21 Jun 2011 06:33:42 -0700, you wrote: >On 6/20/2011 11:35 PM, Matt Zilmer wrote: > >> I'm using the Trimble Thunderbolt here, with good results. I ordered >> two units from one of the eBay vendors. These shipped from within the >> US and were less than $80 each. > > What are the stability and accuracy of these devices in parts > per billion (10^12)? For 80 bucks you're not going to get a > rubidium or cesium standard, and zero-beating WWV will only > give you 1 part in 10^7 for a one-second measurement. > > (Pardon my cynicism - my former network frequency standard > needed something like 1 part in 10^12 to do the job right.) > >-- 73 de K2ASP - Phil Kane >Elecraft K2/100 s/n 5402 > >__ >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 __ 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
Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
> What are the stability and accuracy of these devices in parts > per billion (10^12)? For 80 bucks you're not going to get a > rubidium or cesium standard The $80 Trimble Thuderbolts as well as most GPS-DO units will do 10^-12. My long-term 24 hour average is 10^-13 as reported by KE5FX software. So, as long as the unit is locked to the GPS satellites, you can achieve long-term Rubidium accuracy and about one decimal point away from cesium. Short-term accuracy is around 10 ^-11 although one of my Thunderbolts shows 10^-12 at start up and stays there. Locking the GPS-DO is as easy as throwing a tiny GPS antenna out the window. Mine is resting on decorative brick wall and fed with about 15 feet of RG-174. These antennas are plentiful on the Internet for about USD $15 each. True, the GPS-DO together with the K3 will not provide anywhere near the accuracy stated above since the K3 will be frequency locked to the external oscillator, and not phase locked. But, the output of the GPS-DO can be split and fed to other transceivers (e.g., Icom 77700/7800, ADAT, etc), or used as a test equipment reference. The Trimble Thunderbolt has extraordinary phase noise performance as documented by KE5FX, typically about 10 dB better than other GPS-DO units in the area of 10Hz to 1 kHz from Fc. So, it may be overkill for the K3, but the device may come in handy at a future date where its full potential can be exploited. Paul, W9AC __ 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
Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
On 6/20/2011 11:35 PM, Matt Zilmer wrote: > I'm using the Trimble Thunderbolt here, with good results. I ordered > two units from one of the eBay vendors. These shipped from within the > US and were less than $80 each. What are the stability and accuracy of these devices in parts per billion (10^12)? For 80 bucks you're not going to get a rubidium or cesium standard, and zero-beating WWV will only give you 1 part in 10^7 for a one-second measurement. (Pardon my cynicism - my former network frequency standard needed something like 1 part in 10^12 to do the job right.) -- 73 de K2ASP - Phil Kane Elecraft K2/100 s/n 5402 __ 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
Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
Hi John, I'm using a G3RUH GPSDO for PC time setting and external 10MHz reference, BUT not connected to my K3. I'm very satisfied with it. I've not used this source for the K3, because i will not use the "uCrtlr counting" method of "lock". Not sure if they are no phase jump with this procedure? If a loop locked external reference would be used, i certainly had connected the GPSDO. I can understand that a "bad" external reference would lower the very good phase noise figure of the K3. My best 73, Rudi, HB9ARI On 21.06.2011 07:55, John Bekema wrote: > Hi, > > Would this be interesting? > > http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm > > OH2GBA, > John > > 2011/6/21 David and Dianne on Comcast: >> Hi Everyone, >> >> I am considering a K3EXREF just for fun, no other >> reason. >> >> Looking for suggestions for a reasonably priced 10 >> MHz external signal source. >> >> Can anyone offer some suggestions? GPSDO? OCXO? >> Rubidium Standard? >> >> I have seen some used Trimble Thunderbolt GPSDO's >> on eBay form China. I'm just not sure about the >> wisdom of ordering any of these units. >> >> Suggestions would be appreciated on or off the list. >> >> 73 de N1LQ-Dave > __ > 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 __ 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
Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
Like I guess quite a few others, I have been down the high stability reference route and currently have the following 10 MHz sources: 60 KHz (MSF and possibly WWV) locked plain crystal oscillator, it's based on the G4JNT MK2 from RadCom (http://www.g4jnt.com/freqlock.htm). It works well enough and is easy and cheap to build/align. The limitation is the short term stability which is perhaps academic when used to lock a HF transceiver and is around 1 part in 10^8 (same stability as the older UK Quartzlock 198 KHz units), also I am not sure how immune it would be in the presence of high levels of HF RF. Locks and stable within 5 minutes or so from switch on, low current consumption. Surplus rubidium... These appear from time to time, I was given one by a local surplus dealer who seemed to have more than there was a market for a few years ago. They are used in cellular and similar sites and are probably good for quite a few hours of service, however they have a finite life and appear on the surplus market when removed for upgrade or on routine service, so don't pay much for one. Current drain is quite high, typically needing 2 Amps at 24 Volts initially then dropping after warm up. Stable around 15 ~ 20 minutes from switch on. Needs additional power supply and cabinet/heatsink. GPS controlled crystal oven... Mine appeared on eBay as a part home built unit, there are a variety of these that pop up at times. Mine uses a Toyo high stability OCXO and is superbly stable and will site in perfect sync with the rubidium for days. Locked and stable around 15 ~ 30 minutes from switch on, needs well sited external antenna (not one sitting in the shack window). Current consumption around half that of a rubidium when fitted with an OCXO. The best option of all for a long term accurate reference. If you want an OCXO there are currently several "double ovens" listed on eBay.com for $45 including worldwide shipping from China. They need a GPS or MSF/WWV locked oscillator to set accurately on frequency, warm up time 15 ~ 30 minutes. High stability oscillators/sources can be compared for phase/frequency with a dual beam oscilloscope, listening for a beat note between them is not sufficient at this level of accuracy. I don't plan to fit a K3EXREF, it seems like a nice idea but my K3 was only 2 Hz off frequency at 50 MHz a few days ago and it hasn't been adjusted for several months. My K3 has the KTCXO3-1 fitted and dates from 2007, so the TCXO is fairly well aged by now. 73 Dave, G4AON --- /I am considering a K3EXREF just for fun, no other reason. Looking for suggestions for a reasonably priced 10 MHz external signal source. Can anyone offer some suggestions? GPSDO? OCXO? Rubidium Standard? 73 de N1LQ-Dave/ __ 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
Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
I'm using the Trimble Thunderbolt here, with good results. I ordered two units from one of the eBay vendors. These shipped from within the US and were less than $80 each. eBay has a very well-structured buyer satisfaction policy. If you choose this course, look carefully at the customer satisfaction index your chosen vendor has earned via buyer feedback. 73, matt W6NIA On Tue, 21 Jun 2011 08:55:59 +0300, you wrote: >Hi, > >Would this be interesting? > >http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm > >OH2GBA, >John > >2011/6/21 David and Dianne on Comcast : >> Hi Everyone, >> >> I am considering a K3EXREF just for fun, no other >> reason. >> >> Looking for suggestions for a reasonably priced 10 >> MHz external signal source. >> >> Can anyone offer some suggestions? GPSDO? OCXO? >> Rubidium Standard? >> >> I have seen some used Trimble Thunderbolt GPSDO's >> on eBay form China. I'm just not sure about the >> wisdom of ordering any of these units. >> >> Suggestions would be appreciated on or off the list. >> >> 73 de N1LQ-Dave >__ >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 __ 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
Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
Hi, Would this be interesting? http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm OH2GBA, John 2011/6/21 David and Dianne on Comcast : > Hi Everyone, > > I am considering a K3EXREF just for fun, no other > reason. > > Looking for suggestions for a reasonably priced 10 > MHz external signal source. > > Can anyone offer some suggestions? GPSDO? OCXO? > Rubidium Standard? > > I have seen some used Trimble Thunderbolt GPSDO's > on eBay form China. I'm just not sure about the > wisdom of ordering any of these units. > > Suggestions would be appreciated on or off the list. > > 73 de N1LQ-Dave __ 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
Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
Me too! Jim Ke4wy On Jun 20, 2011, at 9:31 PM, vr2xmc wrote: > I am also interested in that information . Could any of you share on this > forum as 'OT' > > Sent from my iPhone 4 > > David and Dianne on Comcast 於 2011年6月21日 上午9:11 寫道： > >> Hi Everyone, >> >> I am considering a K3EXREF just for fun, no other >> reason. >> >> Looking for suggestions for a reasonably priced 10 >> MHz external signal source. >> >> Can anyone offer some suggestions? GPSDO? OCXO? >> Rubidium Standard? >> >> I have seen some used Trimble Thunderbolt GPSDO's >> on eBay form China. I'm just not sure about the >> wisdom of ordering any of these units. >> >> Suggestions would be appreciated on or off the list. >> >> 73 de N1LQ-Dave >> >> __ >> 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 > __ > 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 __ 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
Re: [Elecraft] Suggestions for 10 MHz Signal Source for the K3?
I am also interested in that information . Could any of you share on this forum as 'OT' Sent from my iPhone 4 David and Dianne on Comcast 於 2011年6月21日 上午9:11 寫道： > Hi Everyone, > > I am considering a K3EXREF just for fun, no other > reason. > > Looking for suggestions for a reasonably priced 10 > MHz external signal source. > > Can anyone offer some suggestions? GPSDO? OCXO? > Rubidium Standard? > > I have seen some used Trimble Thunderbolt GPSDO's > on eBay form China. I'm just not sure about the > wisdom of ordering any of these units. > > Suggestions would be appreciated on or off the list. > > 73 de N1LQ-Dave > > __ > 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 __ 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
[Elecraft] Suggestions for 10 MHz Signal Source for the K3?
Hi Everyone, I am considering a K3EXREF just for fun, no other reason. Looking for suggestions for a reasonably priced 10 MHz external signal source. Can anyone offer some suggestions? GPSDO? OCXO? Rubidium Standard? I have seen some used Trimble Thunderbolt GPSDO's on eBay form China. I'm just not sure about the wisdom of ordering any of these units. Suggestions would be appreciated on or off the list. 73 de N1LQ-Dave __ 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
