Re: [time-nuts] Next Generation Time/Frequency Standards May Require Provisions Preventing Vertical Displacement
Magnus Danielson wrote: On 09/30/2010 06:14 AM, jimlux wrote: Magnus Danielson wrote: Doppler effects is much more important, and it's effects is being treated regularly, such as when talking in the GSM phone while driving the car... Hmm.. I think crystal oscillator frequency variation in the phone is a bigger factor. Let's say you're zipping down the road at 200 km/hr (55m/s), texting your friends. That's about 0.2ppm Doppler or around 400 Hz (for a 2 GHz carrier).. as noted.. the XO probably has 1ppm (at best.. more like 10ppm) On why there is a big market for small but stable TCXOs at 26 MHz. how stable? I'm sort of curious, I wonder what sort of temperature range cellphones are expected to really work over.. (not necessarily what they're specified for, but what the designers see as the "sweet spot").. It's not like people carry their phones in pocket on the back of a backpack in -40 weather. I wonder if they're like pager receivers in some sense (e.g. they're on all the time, waiting for a call) And, as the phone heats up as you transmit, how much does the frequency change? It's a real cost sensitive huge volume market, so the specs for a cellphone reference oscillator could be highly tailored to a specific application. ___ 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.
[time-nuts] 10 MHz Frequency Standard
Hello Time-Nutters, I would like to get a 10 MHz frequency standard for My Lab, and would like some information on what would be the best choice and would like to know the difference from EFRATOM LPRO-101 Rubidium 10MHZ Frequency Standard and Thunderbolt PRECISION GPS 10mhz FREQUENCY&TIME Standard any help would be very much appreciated. Thank You, Sal C. Cornacchia From: Brian Kirby To: Discussion of precise time and frequency measurement Sent: Wed, September 29, 2010 10:03:11 PM Subject: Re: [time-nuts] Allan Variance And ALAVAR http://www.alamath.com/index.php?option=com_content&task=view&id=12&Itemid=30 And PLOTTER http://ulrich-bangert.de/html/downloads.html On 9/29/2010 11:18 AM, Martyn Smith wrote: > Hello, > > Can anyone recommend software to calulate the Allan varaince from a set > of data? > > I have taken many measurements with the SR620 using it's 500 second gate > and downloaded the results into Excel. > > I can use the SR620 itself to calulate the Allan Variance. However, I > want to know the Allan Varaince over a 1 second sample instead of > 500 seconds. > > Hoping to plug the data into software and get the result!! > > Regards > > Martyn > > > > > No virus found in this outgoing message. > Checked by AVG - www.avg.com > Version: 9.0.856 / Virus Database: 271.1.1/3166 - Release Date: 09/29/10 >06:37:00 > > > > ___ > 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. ___ 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. ___ 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] Next Generation Time/Frequency Standards May Require Provisions Preventing Vertical Displacement
On 9/30/2010 8:43 AM, jimlux wrote: > > how stable? The parts are generally ~ 1 ppm over temp and another ppm or two aging. > I'm sort of curious, I wonder what sort of temperature range > cellphones are expected to really work over.. depends on the vendor to some extent. Not all standards spec an operating temp range. The bottom end is usually -20 or -40 C though not at full spec, and -40 is pretty rare. > (not necessarily what they're specified for, but what the designers > see as the "sweet spot").. It's not like people carry their phones in > pocket on the back of a backpack in -40 weather. Most phones are not specified to operate this cold. Even standards that specify operating temperature range are often not fully complied with. > > I wonder if they're like pager receivers in some sense (e.g. they're > on all the time, waiting for a call) No, a lot of effort is spent in letting them spend most of their time in standby and only wake up every second (or few seconds.) Most modern pagers do the same thing. They indicate to the receiver when they will be sending data, and when they will be sending device addresses (generally called the paging interval for cellphones and pagers both.) > > And, as the phone heats up as you transmit, how much does the > frequency change? Once the phone is participating in the network it's locked to it. At that point the only thing we care about in the TCXO is short term (~ 1sec) drift and that's WAY better than 1 ppm. If you are "transmitting" you are still receiving several times a second and getting frequency offset updates at the same rate. It's closed loop. > > It's a real cost sensitive huge volume market, so the specs for a > cellphone reference oscillator could be highly tailored to a specific > application. Yup, and stamped out in the millions per month so they are really cheap. Well under a buck. Most are just a slab of silicon, a slab of quartz, and a package. All oscillator functions and compensation are provided in a custom bit of CMOS with EEPROM or fuse programmable compensation memory. I didn't think this was possible, but I saw one yesterday in a GS that was in an SSOT-23 package. Sheesh. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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.
[time-nuts] Small quantity custom crystals
I need to build some small tracking transmitters (using a circuit similar to http://www.jbgizmo.com/page4.html This circuit uses a fifth overtone crystal to get an output in the 216 to 220 MHz range. The circuit is rather finicky about the crystal and transistor... most don't work. Smaller and more rugged crystals are preferred. Does anybody know of a place that can make 1 off crystals in this range for a reasonable price. Many of usual suspects don't seem to be able to make crystals in that range. ___ 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] Small quantity custom crystals
Mark Sims wrote: > > I need to build some small tracking transmitters (using a circuit similar > to http://www.jbgizmo.com/page4.html > > This circuit uses a fifth overtone crystal to get an output in the 216 to > 220 MHz range. The circuit is rather finicky about the crystal and > transistor... most don't work. AFAIK, that is way too high a frequency for 5th overtone. Has something changed? Are you sure there isn't a frequency doubler after the oscillator? Anyway, you can get a complete synthesizer on a chip from Analog Devices that uses very low power (see the ADF4360-8) so you might want to consider that as an alternative. Rick Karlquist N6RK ___ 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] Small quantity custom crystals
Mark to my inexpert eye that doesnt look like a very good overtone oscillator but I appreciate that it is slimmed down to keep the weight and size down, I can see why it is touchy. There is nothing to make the oscillator degenerate at the crystal fundamental. In fact it looks like a Pierce with a tuned circuit in the anode. If it goes off at the overtone my guess is that it by luck! But there are more clever people than me in this Group who may be more useful to you. Old fashioned crystals (lapped to frequency) used 5th OT up to just over 100MHz and the 7th and then 9th the blank was too fragile to go further. I believe modern micro machining techniqes where a thicker ring of quartz surrounds the resonator will allow a 5th overtone operation at 200MHz but you still have to make sure it doesnt go off at the fundamental or the 3rd .it may still transmit, but it will be off-channel and lower in power. Overtones are not harmonics.in radio anyway. Alan G3NYK - Original Message - From: "Mark Sims" To: Sent: Thursday, September 30, 2010 7:57 PM Subject: [time-nuts] Small quantity custom crystals I need to build some small tracking transmitters (using a circuit similar to http://www.jbgizmo.com/page4.html This circuit uses a fifth overtone crystal to get an output in the 216 to 220 MHz range. The circuit is rather finicky about the crystal and transistor... most don't work. Smaller and more rugged crystals are preferred. Does anybody know of a place that can make 1 off crystals in this range for a reasonable price. Many of usual suspects don't seem to be able to make crystals in that range. ___ 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. ___ 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] 10 MHz Frequency Standard
LPRO needs to be calibrated. Once calibrated, should be pretty good for a reasonable period of time, depending on what your performance criteria are, probably a year or so for amateur radio type stuff. Thunderbolt is linked to NIST, via the GPS satellites, and never needs calibration. LPRO more of a 'transfer standard', Thunderbolt more of a 'primary standard'. Price, probably, slightly cheaper for the LPRO but I prefer the Thunderbolt. It goes from 'off' to locked to GPS in about 10 minutes or less (not the first time though) once your antenna is installed and not moving around. Joe -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com]on Behalf Of SAL CORNACCHIA Sent: Thursday, September 30, 2010 10:44 AM To: Discussion of precise time and frequency measurement Subject: [time-nuts] 10 MHz Frequency Standard Hello Time-Nutters, I would like to get a 10 MHz frequency standard for My Lab, and would like some information on what would be the best choice and would like to know the difference from EFRATOM LPRO-101 Rubidium 10MHZ Frequency Standard and Thunderbolt PRECISION GPS 10mhz FREQUENCY&TIME Standard any help would be very much appreciated. Thank You, Sal C. Cornacchia From: Brian Kirby To: Discussion of precise time and frequency measurement Sent: Wed, September 29, 2010 10:03:11 PM Subject: Re: [time-nuts] Allan Variance And ALAVAR http://www.alamath.com/index.php?option=com_content&task=view&id=12&Itemid=3 0 And PLOTTER http://ulrich-bangert.de/html/downloads.html On 9/29/2010 11:18 AM, Martyn Smith wrote: > Hello, > > Can anyone recommend software to calulate the Allan varaince from a set > of data? > > I have taken many measurements with the SR620 using it's 500 second gate > and downloaded the results into Excel. > > I can use the SR620 itself to calulate the Allan Variance. However, I > want to know the Allan Varaince over a 1 second sample instead of > 500 seconds. > > Hoping to plug the data into software and get the result!! > > Regards > > Martyn > > > > > No virus found in this outgoing message. > Checked by AVG - www.avg.com > Version: 9.0.856 / Virus Database: 271.1.1/3166 - Release Date: 09/29/10 >06:37:00 > > > > ___ > 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. ___ 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. ___ 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. ___ 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] Small quantity custom crystals
I suspect that International Crystal is in the "usual suspects" category, but they do list operation of some of their 7th overtone parts to 200 MHz and you are not too far past that. I'd call them if you haven't already. there price probably won't be what you'd score as reasonable, but if you want something that works, they are likely to provide it. What's magic about these? There are smaller solutions these days. On 9/30/2010 1:57 PM, Mark Sims wrote: > I need to build some small tracking transmitters (using a circuit similar to > http://www.jbgizmo.com/page4.html > > This circuit uses a fifth overtone crystal to get an output in the 216 to 220 > MHz range. The circuit is rather finicky about the crystal and transistor... > most don't work. > > Smaller and more rugged crystals are preferred. Does anybody know of a place > that can make 1 off crystals in this range for a reasonable price. Many of > usual suspects don't seem to be able to make crystals in that range. > > > ___ > 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. -- mailto:o...@ozindfw.net Oz POB 93167 Southlake, TX 76092 (Near DFW Airport) ___ 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.
[time-nuts] Small quantity custom crystals
I have had good results using International Crystal. You can send them a crystal that works in your circuit and they will make a duplicate! Corby Dawson Moms Asked to Return to School Grant Funding May Be Available to Those That Qualify. http://thirdpartyoffers.juno.com/TGL3141/4ca4f6c279b9cce6dm04duc ___ 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] Small quantity custom crystals
To ease the requirements on your crystal, you might consider using a diode frequency multiplier to bring your oscillator frequency into that range. Wenzel has a good app note on one variety: http://www.wenzel.com/documents/2diomult.html --n On Thu, 2010-09-30 at 18:57 +, Mark Sims wrote: > I need to build some small tracking transmitters (using a circuit similar to > http://www.jbgizmo.com/page4.html > > This circuit uses a fifth overtone crystal to get an output in the 216 to 220 > MHz range. The circuit is rather finicky about the crystal and transistor... > most don't work. > > Smaller and more rugged crystals are preferred. Does anybody know of a place > that can make 1 off crystals in this range for a reasonable price. Many of > usual suspects don't seem to be able to make crystals in that range. > > > ___ > 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. ___ 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] Small quantity custom crystals
When I was in the television transmitter biz, we ran 5th, 7th and 9th up to 216MHz using JFET Pierce oscillators. We used the same oscillator for low VHF to high VHF and only changed an LC circuit to make sure the oscillator would "take off" on the correct overtone. Our supplier of choice was Piezo Crystals. Ovenized at 65C and IIRC we used SC cut crystals. Not cheap, but we never had crystal problems. Also, a design engineer at Piezo named Lynn Heischman was always available as a consultant for osc and crystal design, even though we were a small quantity purchaser. Dave W8NF --- On Thu, 9/30/10, Rick Karlquist wrote: > From: Rick Karlquist > Subject: Re: [time-nuts] Small quantity custom crystals > To: "Discussion of precise time and frequency measurement" > > Date: Thursday, September 30, 2010, 12:12 PM > Mark Sims wrote: > > > > I need to build some small tracking transmitters > (using a circuit similar > > to http://www.jbgizmo.com/page4.html > > > > This circuit uses a fifth overtone crystal to get an > output in the 216 to > > 220 MHz range. The circuit is rather finicky about > the crystal and > > transistor... most don't work. > > AFAIK, that is way too high a frequency for 5th > overtone. Has > something changed? Are you sure there isn't a > frequency doubler > after the oscillator? > > Anyway, you can get a complete synthesizer on a chip from > Analog > Devices that uses very low power (see the ADF4360-8) so > you > might want to consider that as an alternative. > > Rick Karlquist N6RK > > > ___ > 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. > ___ 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.
[time-nuts] Small quantity custom crystals
I'm not sure if the thing actually operates on the 5th overtone. I have some mystery TO5 44.7 MHz crystals that it puts out 223.5 MHz. The actual freq at the collector seems to be 74.5 MHz (but it is a complex waveform). The circuit generates a short burst every second or two. It is VERY low net power. It runs for weeks on a couple of LR44 cells but can be tracked a mile away laying on the ground. This app needs to be fairly cheap as the transmitters will not be recovered. Circuit cost is a few cents plus the crystal. Commercial transmitters are $150-$250 dollars. These types of circuits are usually hand built out of hand selected components. They are tweaked until they work then potted up in epoxy. There are only a very few people who make them (in hollow trees, dark dungeons, and troll infested caves) and they keep their circuits and suppliers secret. I once did some work for a company that made road construction flashers... much the same. All hand selected parts to get the right flash rate, intensity, and minimal power draw. Much more art than science behind these things. International built me some crystals a while back, but none could be made to work. ___ 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.
