Re: [time-nuts] How accurate are cheap radio controlled clocks?
On 25/06/11 20:19, Dr. David Kirkby wrote: I've got one of the cheap radio-controlled clocks? I was listing to radio 4 the other day and herd the time signal. The radio controlled clock was about 3 seconds off. I was a bit surprised it was so far off. I'm just wondering how accurate these things are. Typically better than 1s. If there is interference or the radio is disabled, it won't be able to receive the time signal. Switch mode PSUs and CRT TVs or computer monitors can interfere with the 60kHz time signal. The clocks with an LCD display usually have an indicator which shows signal strength if the clock successfully updated in the last hour. If you have reception problems, try moving the clock. The built-in ferrite rod is very directional. Were you receiving Radio 4 on LW or via a digital service. You could easily see a 3s delay on digital radio or TV. -- Linux 2.6.32 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Us Time Nuts and... Wrist Watches.
On 24/12/10 17:00, Michael Poulos wrote: What is your favorite watch? This one gets my vote: http://leapsecond.com/pages/atomic-bill/ -- Linux 2.6.35 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] what is the best way to multiply a 10 Mhz signal?
On 21/12/10 16:35, Stephen Farthing wrote: Hi everyone, I want to multiply the output from my Efratom 101 (10Mhz) to clock a DDS at 70 Mhz. Has anyone tried this? Regards, Steve G0XAR What is the application? What will the DDS output frequency be? Maybe you could use a 70MHz (or whatever frequency you need) VCO as the DDS clock and use the DDS as a programmable divider to produce a 10MHz output. This could be phase locked to the 10MHz output from the LPRO-101. -- Linux 2.6.35 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Giuseppe Marullo wrote: Hi all, just subscribed, I would like a quick advice on a 10MHz reference for calibrating my instruments and for fun. In particular, I would like to know if you could give me advice on EFRATOM FRS-A,FRS-C, DATUM LPRO-101, Thunderbolt and such. I would prefer a GPSDO (like the Thunderbolt), but budget is very tight (about 100EUR), so I am searching old surplus stuff on Ebay.snip A timing GPS receiver with a built-in 10MHz oscillator would fit your budget nicely. The Navsync CW12-TIM looks like the obvious choice. You would need the CW12-TIM module, a 3.3V DC supply and a suitable aerial/antenna. Power consumption is well below 1W. It has a 1PPS output with 30ns RMS accuracy and a NCO output with a default output frequency of 10MHz. http://www.navsync.com/docs/CW12-TIM_DS.pdf I paid just over Eur50 for mine last year when the Euro was very strong against foreign currencies. -- Linux 2.6.30 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Timenoob - Cheap and simple 10MHz reference
Richard W. Solomon wrote: Does the factory sell direct in small quantities ? 73, Dick, W1KSZ I don't think so. I live in Cork, Ireland. Navsync are in Shannon about 70 miles from here. I ordered my CW12-TIM from Cutter Electronics in Australia. As they were out of stock at the time, I had to wait for a couple of weeks, while Navsync shipped them 20,000 miles from Ireland to Australia and back again :-) -- Linux 2.6.30 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] EFRATOM LPRO-101 Connector
Richard W. Solomon wrote: How do folks like to connect to this RbO ? Do they use a connector ? Or just solder to the pins ? If they use a Connector can you tell me the Make Part Number ? Thanks, Dick, W1KSZ Cut up a DIP socket. Don't use a nice turned-pin type. Cheap and nasty ones work best. You need two rows of five pins each. Not pretty, but better than soldering the pins. -- Linux 2.6.26 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Low cost GPS gadgets for timing
Hal Murray wrote: The problem is that most of the low-cost GPS toys use the SiRF chip set. It sucks for timing. It looks like the NMEA sentences are sent from a timer with 100 ms ticks. http://www.megapathdsl.net/~hmurray/ntp/GPSSiRF-off.gif A lot of SiRFstar III based devices have a 1pps pin, but you might have to crack them open with a hammer to find it. Claimed accuracy is 1 microsecond, but I find my cheap bluetooth GPS receiver is always within a few tens of ns compared to a Navsync CW12-TIM, Rockwell Jupiter and Garmin GPS 18. I have read some words of wisdom on the web which say that the SiRFstar III is not suitable for use in a GPSDO, but I can't see any reason for this. One thing to be aware of when you are searching for the PPS output is that the PPS duration is only 1 microsecond which makes it difficult to spot on an analogue scope. -- Linux 2.6.26 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] time-nuts Rockwell Jupiter 12-channel GPS receiver OEM module
Mike Monett wrote: If nobody has already mentioned it, Fluke.1 has the Rockwell Tu00-D205 high performance 12-channel GPS receiver OEM modules for $9.99 ea with free shipping worldwide, item number: 290306684157 These appear to have the 10KHz output described at http://www.jrmiller.demon.co.uk/projects/ministd/frqstd.htm This website sells them too: http://www.weirdstuff.com/cgi-bin/item/20164 I wonder if it is suitable for use in a GPSDO? It looks quite different to the Jupiter T used in James Miller's design and the other Jupiters that Fluke.1 has sold in the past. -- Linux 2.6.26 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] Datum / Efratom LPRO 101 - ebay
Now I was wondering what about these oscillators. Why are they offered so cheap and so many. What have they be used for ? These are from used equipment so they can't be expected to last as long as a new unit. They are probably from surplus telecomms equipment. Also I cannot find any information about the manufacturer on the internet. Are they out of business ? Datum were taken over by Symmetricom. http://www.symmetricom.com/ Would such a oscillator be usefull for us, as we need a 10Mhz signal with about 1e-8 precision. Thanks a lot ! nils The LPRO-101 sounds like the ideal candidate for this job. From memory, I think the long term stability spec is 1e-9/10 years, 5e-11/month. I have had very good service from this seller: http://myworld.ebay.de/fluke.l/ Friendly helpful and reliable. Very quick shipping from China by EMS. I'm not connected to this seller in any way, just another happy customer. A GPSDO is another cost effective solution that would easily meet your requirements. The Trimble Thunderbolt is widely available on eBay. You should also check out the CW12-TIM module from Navsync. Ed. -- Linux 2.6.26 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] pi Day
Rex wrote: I don't recall this discussion here before, but it should be a good time sink. I was reminded tonight that pi Day is coming on 3/14. That's fine, but a little inaccurate for our kind. We won't have it until the 31st of April on this side of the pond. -- Linux 2.6.26 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] 10Mhz source?
Lee Reynolds wrote: Hi, people. I'm in need of an extremely accurate 10MHz signal source (doing some alignment of receiver TXCOs.) Would anyone know of a source I could either visit or borrow in NH/VT? How accurate does it need to be? An OCXO tuned to zero beat with WWV will easily get you within 1Hz. 10MHz OCXOs are easy to find on eBay. Failing that, what's a reasonable plan for buying one that won't break my piggy bank? I see that there are a fair number of those Trimble GPS clock units showing up on eBay but have no idea of their utility... TIA, Lee There are a few GPSDOs with a 10MHz output. The Trimble units would be ideal. Also look at the Navsync CW12-TIM. If you fancy a bit of homebrew, see James Miller's excellent design: http://www.jrmiller.demon.co.uk/projects/ministd/frqstd0.htm -- Linux 2.6.26 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
Re: [time-nuts] WTB: 10, 20, 40 or 50MHz oscillator
David Hilton-Jones wrote: Does anybody (preferably in the UK for PP) have surplus to their requirements a stable oscillator producing a sine wave at 10, 20, 40 or 50MHz at 5-10dbm? Thanks David, G4YTL eBay is the best place to find OCXOs at a reasonable price. Searching for OCXO rarely turns up anything other than OXO cubes. A search for frequency standard finds four from UK sellers. Two reasonably priced, the other two a bit too expensive for my budget. http://search.ebay.co.uk/search/search.dll?from=R40_trksid=m37satitle=frequency+standard Ed. EI9GQ. -- Linux 2.6.18 ___ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
