Re: [time-nuts] Frequency counter recommendation
Only one comment. I'm working on moonbounce and radio astronomy. I don' want no steenkin' wireless around the shop. How about wired network interface? Don Chris Albertson What I was talking about was the process to move the project forward, not design or requirements details. So my list of moduals was just to show what a list of modulas might look like, not to suggest those exact ones. Jumping ahead to design. No one wants a serial RS232 interface. they don't even make computers with RS232 ports much any more. Those guys that designed equipment that forced people to load costom USB drivers just did not think. There is no need for that. What you do is make you project appear to be some standard USB class and then the OS (Linux, Windows or Mac OSX) will already have a driver. That VNA should have presented itself as a serial port. And then the software could read from a serial port. But of course there would be not physical RS232 device. If you have to select an interface I'd rather have any wireless type. WiFi or Bluetooth. But if you are building a modular system you do NOT want to pick one. You just make a project standard to use (say) I2C, SPI, two wire ir whatever. Then the counter module is controlled by i2c and if you want to connect it to a computer you build the USB module but if you want a stand alone no-computer instrument you build the front panel that has LED numbers. That is the entire ont is modular, you avoid this kinds of decisions and allow for easy upgrade as technology changes. Other questions to resolve are how many slices to cut the pie into. I would argue for very small single funtions bulding blocks so we don't have the HPSDR problem of years of time to design each one. Selecting a physical chassis to use willl take time. I like the idea of using a disk enclosure because then you can buy a 1U or 8U rack or an old PC chassis, If you modual looks like a disk there are plenty of things it can fit into. From my experience, for something like this to take off one person has to take ownership of the project and run with it, make the web site, write some golas and build something that works. Only then do other jump in and help. It really would be good to have a Time and Frequency Instrumentation Project as currently the state of the art seem to be that you simply buy something from a Chinese eBay reseller. This is hardly what I'd cal innovation. On Thu, Dec 16, 2010 at 7:44 PM, Bob Bownes bow...@gmail.com wrote: Very good points. For the core counter, are you talking about an interval counter or a more generic two input, tell the CPU what to do with the inputs kind of model? :) USB certainly would be the interface of choice, but serial also has it's place. The joy is there is less software to write. That engenders a whole discussion about a standalone counter vs a PC based counter. Fine example is the two VNA projects out there. One of them requires a whole bunch of ugly USB drivers to work and it isn't even recognized by a Mac for example. You can still do spiffy GUI front ends and USB-serial adaptors are going to be around for a while. Or you use an Arduino core and don't worry about drivers. Gonna be a religious war I suspect. Standalone model circumvents all that. :) I suspect a number of input modules could be described. Prescalers, amplifiers, attenuators, terminations, filters, all come to mind looking at the input options on gear on the bench. I have a nice variant on the VE2ZAZ design already done that would get it up to ~18Ghz. Again, several core synthesizers could be defined based on requirments. GPSDO, 10Mhz in, txco all come to mind. Define a power supply that doesn't exceed 12v and you are in pretty good shape. COT technology would be a good choice. The point about the TAPR bus and enclosure is also a great one. PC cases are nice, but bulky. Last thing I want is another one of those kicking around. 1U rackmount would be nice, but makes the module design difficult. 2U much easier, but harder to come by cheap cases. I think an overall target design would be the place to start. PICTIC II is also a good place to start. Shoot for a 10x improvement? :) I'm not all that fond of Wiki's but if there are people serious about the project, I can put one up. Main mailing list certainly isn't the place to design it. All that said, I don't know enough to design it alone, but I have the ability to fabricate prototypes and can build to someone else's specs. And I'm serious about wanting a better counter than my 5328. :) Bob On Thu, Dec 16, 2010 at 9:53 PM, Chris Albertson albertson.ch...@gmail.com wrote: You can't do anything, not even guess at a price until you have a list of requirements written down. And they need to be detailed. I would break the project down into a set of sub-projects possably like this 1) The core counter, just counts, no pre scaler, no display or
Re: [time-nuts] Frequency counter recommendation
If your spend is in that sort of region it doesn't cost a great deal more to get a batch of boards professionally pasted, picked, placed and reflowed. Regards, David Partridge -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: 16 December 2010 19:20 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Frequency counter recommendation Hi Yes indeed, been there done that. Not very hard at all. All you need is the six layer pc board (can be bought), the FPGA (Digikey has them), a few of these and a couple of those. Spend less than $100 and you are in business if the PC board volume is high enough. In this case the next step in the business is to solder the 256 ball 1 mm spacing BGA package down on the pc board. Not so easy without the right tools... Bob ___ 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] Frequency counter recommendation
One possible relatively simple module could use an ACAM TDC-GP2 to compare the relative stability of a pair of low noise oscillators. Performance comparable to a 5370A/B at a fraction of the power, weight should be achievable in this application. One of the oscillators would be divided down to at least 1KHz and used to drive the start input whilst the undivided oscillator output drives the 1st stop channel and the other oscillator drives the 2nd stop channel. The divider output jitter need not be state of the art as its only used to arm the device. However its clock to output delay should be somewhat less than 1 period of the input frequency. The ACAM TDC-GP2 uses an SPI interface. In principle one can process all 4 hits in each of the 2 stop channels to reduce the noise. The usable oscillator frequency range is around 200KHz to 50MHz. Bruce David C. Partridge wrote: If your spend is in that sort of region it doesn't cost a great deal more to get a batch of boards professionally pasted, picked, placed and reflowed. Regards, David Partridge -Original Message- From: time-nuts-boun...@febo.com [mailto:time-nuts-boun...@febo.com] On Behalf Of Bob Camp Sent: 16 December 2010 19:20 To: 'Discussion of precise time and frequency measurement' Subject: Re: [time-nuts] Frequency counter recommendation Hi Yes indeed, been there done that. Not very hard at all. All you need is the six layer pc board (can be bought), the FPGA (Digikey has them), a few of these and a couple of those. Spend less than $100 and you are in business if the PC board volume is high enough. In this case the next step in the business is to solder the 256 ball 1 mm spacing BGA package down on the pc board. Not so easy without the right tools... Bob ___ 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] ACAM pricing? [was Re: Frequency counter recommendation]
At 04:36 AM 12/17/2010, Bruce Griffiths wrote: One possible relatively simple module could use an ACAM TDC-GP2 to compare the relative stability of a pair of low noise oscillators. Speaking of the ACAM parts, has anyone received pricing lately? I was quoted around $30 for the TDC-GP2 and over $200 for the GPX in small quantities early this year. -- newell N5TNL ___ 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] Frequency counter recommendation
Interesting discussion.. comments interspersed Chris Albertson wrote: Jumping ahead to design. No one wants a serial RS232 interface. they don't even make computers with RS232 ports much any more. Those guys that designed equipment that forced people to load costom USB drivers just did not think. There is no need for that. What you do is make you project appear to be some standard USB class and then the OS (Linux, Windows or Mac OSX) will already have a driver. That VNA should have presented itself as a serial port. And then the software could read from a serial port. But of course there would be not physical RS232 device. If you have to select an interface I'd rather have any wireless type. WiFi or Bluetooth. wireless interface and RF test equipment is a bad combination. If you're trying to measure small scale performance (e.g. timing at 1E-10 levels), small amounts of RF leaking in/out causes problems. This is one of the things that separates good test equipment from great equipment. It's hard to get better than 100dB isolation from packaging, and if you're looking for things at the -150dBm level, something at 0dBm is huge. But if you are building a modular system you do NOT want to pick one. You just make a project standard to use (say) I2C, SPI, two wire ir whatever. Then the counter module is controlled by i2c and if you want to connect it to a computer you build the USB module but if you want a stand alone no-computer instrument you build the front panel that has LED numbers. That is the entire ont is modular, you avoid this kinds of decisions and allow for easy upgrade as technology changes. IR/fiber optic interfaces are very intriguing. Too bad that the plastic fiber stuff costs more than conventional wires/connectors. Other questions to resolve are how many slices to cut the pie into. I would argue for very small single funtions bulding blocks so we don't have the HPSDR problem of years of time to design each one. Against that: every connection causes potential troubles. A better solution for the generalized case is to put multiple functions together, but don't necessarily connect them all. Think of the old IF strip chips. Oscillator, amplifiers, variable gain stages, detectors, all on the same chip but the ins and outs brought out to pins. I don't think you want to bring them out to connectors, but, rather, provide a way to do interconnections, etc. Selecting a physical chassis to use willl take time. I like the idea of using a disk enclosure because then you can buy a 1U or 8U rack or an old PC chassis, If you modual looks like a disk there are plenty of things it can fit into. old pc chassis is a very limited life item in a particular configuration. do you mean my old IBM PC? Or an AT? or a tower case? or a midsize case? When you say disk drive size, do you mean 5 1/4 floppy/CD-ROM/DVD or something else. Packaging is going to be critical for high performance. Look at boxes from COMPAC, for instance. From my experience, for something like this to take off one person has to take ownership of the project and run with it, make the web site, write some golas and build something that works. Only then do other jump in and help. It really would be good to have a Time and Frequency Instrumentation Project as currently the state of the art seem to be that you simply buy something from a Chinese eBay reseller. This is hardly what I'd cal innovation. ___ 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] FEI-Zyfer GPS Time Frequency Module
They have all sold and all but one for over $100. Seems someone thought they were worth something. ___ 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] ACAM pricing? [was Re: Frequency counter recommendation]
On Fri, Dec 17, 2010 at 2:49 PM, Scott Newell new...@cei.net wrote: Speaking of the ACAM parts, has anyone received pricing lately? I was quoted around $30 for the TDC-GP2 and over $200 for the GPX in small quantities early this year. -- We are expecting 10 TDC-GPX from the Swiss distributor for 205 CHF each, with a 10% discount, i.e. 184.50 CHF/chip. Javier ___ 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] ACAM pricing? [was Re: Frequency counter recommendation]
184.50 CHF/chip = 190 usd, what is wrong with this world the overprinted usd should not be on par with CHF that is the Swiss francs correct ? Stanley - Original Message From: Javier Serrano javier.serrano.par...@gmail.com To: Discussion of precise time and frequency measurement time-nuts@febo.com Sent: Fri, December 17, 2010 12:04:35 PM Subject: Re: [time-nuts] ACAM pricing? [was Re: Frequency counter recommendation] On Fri, Dec 17, 2010 at 2:49 PM, Scott Newell new...@cei.net wrote: Speaking of the ACAM parts, has anyone received pricing lately? I was quoted around $30 for the TDC-GP2 and over $200 for the GPX in small quantities early this year. -- We are expecting 10 TDC-GPX from the Swiss distributor for 205 CHF each, with a 10% discount, i.e. 184.50 CHF/chip. Javier ___ 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] Truetime dc 468 goes sat rcvr simulator basics working
Just back from a weeks long road trip and indeed the goes clock is still on time. Though it may be slightly ahead by a part of a second visually. I don't think I looked this close when I started the test. However I just fired up wwv and see it is matching the time ticks. So this has been a very good test that checking the gps time and such didn't actually mess up the GOES data stream. So my next steps will be to document this and then share out to the group. Speculate a week or so. Regards Paul WB8TSL On Thu, Dec 9, 2010 at 8:34 PM, paul swed paulsw...@gmail.com wrote: OK I see the list bounced the email. Here is just the truetime pix The truetime dc468 is indeed working. Though the SX28 is just about out of everything. Like program space and variables space Need to dig a bit to see if there is a trick or two for more space. Anyhow it is locked to GPS on start and currently I have it update every 10 minutes. Just trying to see if something goes crazy. Two pixs attached. One the SX28 processor very simple. The thing plugged into the left is the programmer. The other is the operating TrueTime DC468. I am not using the days so the days area represents the day of the month now. Today is the 10th of December UTC. Need to lets this bake in for a couple of weeks. Regards Paul WB8TSL On Thu, Dec 9, 2010 at 8:30 PM, paul swed paulsw...@gmail.com wrote: The truetime dc468 is indeed working. Though the SX28 is just about out of everything. Like program space and variables space Need to dig a bit to see if there is a trick or two for more space. Anyhow it is locked to GPS on start and currently I have it update every 10 minutes. Just trying to see if something goes crazy. Two pixs attached. One the SX28 processor very simple. The thing plugged into the left is the programmer. The other is the operating TrueTime DC468. I am not using the days so the days area represents the day of the month now. Today is the 10th of December UTC. Need to lets this bake in for a couple of weeks. Regards Paul WB8TSL On Mon, Dec 6, 2010 at 10:04 PM, paul swed paulsw...@gmail.com wrote: Well indeed progress the dc468 is now sync'ing to gps on start. Have a dirty fudge factor to get the seconds exactly synced. Don't like it but does work. Did try to use hex as a month indicator and that did not work. As an example Nov would be A and Dec B. But looking at the driver ckts its doesn't look like anything stops you from doing it. I have seen the clock put out a-d in the digits when I had the info feeding them wrong. Need to tinker with that a bit more. I just don't find 100s of days to be useful though easily implemented now that I can get the date. Regards Paul. On Mon, Dec 6, 2010 at 4:38 PM, paul swed paulsw...@gmail.com wrote: I am using a hocky puck unit On Mon, Dec 6, 2010 at 4:35 PM, Bill Hawkins b...@iaxs.net wrote: There are also a lot of GPS hockey pucks that send the NMEA codes to map software in a laptop that are rapidly becoming obsolete. NMEA is adequate for the 468 display. Have three of them, to go with three NIB (except for the manual) DC 468 receivers. Don't need any of them. Bill Hawkins -Original Message- From: paul swed Sent: Monday, December 06, 2010 3:13 PM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] Truetime dc 468 goes sat rcvr simulator basics working Justin, I might think quite a few time Nuts have these. So making progress have build a gps sat message decoder for the GPRMC sentence that gives time and data. I believe most GPS units put that sentence out. Have it decoding time and next is date. Maybe tonight. Then I have to glue this code into the simulator to set the clock. Next will be a update subroutine which is quite tricky as to how the updates done. ___ 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.
