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 <[email protected]> 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 > reference oscillator. connects to computer with USB. > 2) A display and control panel to the instrument can be independent of > a computer. > 3) The "front end" pre-scaler or other kind of signal conditioning unit. > 4) A core frequency synthesizer, no display and so on like the core counters > 5) A A/C mains based power supply > 6) A battery based power supply to be used in place of or in addition to #4 > > If these parts all worked together or at least used the same size PCB > people could get a chassis and start out simple and cheap and build up > a larger system over time. I was going to build a radio this way > once, I may still do it. My idea was to make each card or modular the > same size as a hard disk drive. Then I could use an old sever chassis > intended for hold SCSI disk drives to hold the cards and each card > would have knobs and controls on one end and electrilcal connectors of > the other. Id use a standard scsi 50-pin ribon cable as a backplane > for serial control (i2c) and power. Today I'd use a SATA backplane as > the form factor. They can be pushed into a rack from the front > Something like this : > http://www.sansdigital.com/images/stories/products/HDDRACK5/hddrack5_1.jpg > > The mistakes made by the HPSDR people were that each card is far to > complex. So much so that few people could understand and contribute > to the design and the cards are mostly un-build-able at the hobby > level. and also they did not select an off the self backplane and > enclosure. For most people sheet metal bending is not easy, So you'd > want to specify a common and cheap off the shelf chassis type. > > So,... the first step is to list out the cards and write specs for > each and design it so it is an expandable system A Wiki works best > for this, not an email list. > > On Thu, Dec 16, 2010 at 5:15 PM, Alan Hochhalter <[email protected]> wrote: >> One way to find out if people are interested enough to pledge some money up >> front is something like this project >> >> http://www.kickstarter.com/projects/bushing/openvizsla-open-source-usb-protocol-analyzer >> >> Alan >> >> On 12/16/2010 12:55 PM, Bob Camp wrote: >>> >>> Hi >>> >>> If you look in detail at the ups and downs of the TAPR SDR project, it's >>> not >>> one I would want to emulate. >>> >>> If we have a few hundred people interested with cash in hand, this might >>> indeed make sense. >>> >>> Bob >>> >>> -----Original Message----- >>> From: [email protected] [mailto:[email protected]] On >>> Behalf Of Chris Albertson >>> Sent: Thursday, December 16, 2010 3:36 PM >>> To: Discussion of precise time and frequency measurement >>> Subject: Re: [time-nuts] Frequency counter recommendation >>> >>> Here is an example of doing something like this as a open source >>> design by a group of HAMs >>> http://www.tapr.org/kits_janus.html >>> This is a software defined radio but is close to the complexity we are >>> talking about here. It has a d/a converter and fpga and lots of >>> surface mount parts. TAPR is able to have these made and sell them >>> for $180. >>> >>> While this is a proof by example that such a project can be done I'd >>> not go this route. Better I think to design a modular system where >>> the modules have easy and well defined interfaces and where each can >>> have whatever quality specs are desired. There is a danger with >>> these group project that you run into a requirements "race" to the top >>> and end up with a hard to manufacture and maintain part. I think the >>> HPSDR project did this >>> >>> On Thu, Dec 16, 2010 at 11:20 AM, Bob Camp<[email protected]> wrote: >>>> >>>> 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 >>>> >>>> -----Original Message----- >>>> From: [email protected] [mailto:[email protected]] On >>>> Behalf Of Don Latham >>>> Sent: Wednesday, December 15, 2010 3:48 PM >>>> To: Discussion of precise time and frequency measurement >>>> Subject: Re: [time-nuts] Frequency counter recommendation >>>> >>>> OK, time-nuts, here's the gauntlet. can't "we" generate a design for a >>>> PC-based FPGA or chip setup that would be generally useful as a counter? >>>> We've seen thorough discussions about trigger jitter, which IMHO is the >>>> fundamental problem. And isn't the PIC2 Time base from 10 MHz standard, >>>> all else should be straightforward. >>>> I'm not a designer, just a messer-arounder, or I'd give it a shot. Robot >>>> Basic is a nice PC software maybe. >>>> Don >>>> >>>> J. L. Trantham, M. D. >>>>> >>>>> I suspect that this question will lead to a discussion of Dual Mixers >>>>> but >>>>> as >>>>> far as the counter question goes, I would recommend you consider an HP >>>>> 5370B. >>>>> >>>>> Joe >>>>> >>>>> -----Original Message----- >>>>> From: [email protected] [mailto:[email protected]]on >>>>> Behalf Of Dave M >>>>> Sent: Wednesday, December 15, 2010 1:55 PM >>>>> To: TimeNuts >>>>> Subject: [time-nuts] Frequency counter recommendation >>>>> >>>>> I'm a retired electronics tech and computer programmer. I have a pretty >>>>> decently equipped shop for almost all of my projects and experiments. >>>>> However, my time and frequency equipment is a bit long in the tooth. I >>>>> have >>>>> a couple old HP 5328A counters (commercial version; not the military >>>>> version), one with a 10544, the other with a 10811 oscillator. >>>>> I have an HP Z3801A that has been operating well for several years, and >>>>> recently acquired a TBolt to keep the counters in tune. I also have a >>>>> good >>>>> distribution amp and couple of old Montronics (Fluke) frequency >>>>> comparators. >>>>> What I'm looking for now, is a recommendation for a good low-cost >>>>> (<$400) >>>>> counter that will get me on the way to performing some of the "down in >>> >>> the >>>>> >>>>> grass" noise, jitter and deviation tests that the more learned members >>>>> of >>>>> the group discuss. I know that new equipment is far out of my budget, >>> >>> but >>>>> >>>>> I'm also aware that some of the older, now obsolete (also cheaper) >>>>> equipment >>>>> is quite capable of doing what I want to do. I prefer HP equipment since >>>>> manuals are much easier to find than most other brands. >>>>> I'd also like recommendation for a good low-cost GPIB controller that >>>>> allows >>>>> me to write software to control some of my instruments. I have >>> >>> experience >>>>> >>>>> writing software in BASIC on a Fluke 1722A controller. I've seen these >>>>> controllers on the Bay and other online vendors, but I've not located >>>>> the >>>>> BASIC discs for them. Any advice? >>>>> I realize that a counter is not the only piece that I need, but it's >>> >>> first >>>>> >>>>> on my list. Other, more applicable equipment is on my want list, but >>> >>> will >>>>> >>>>> have to wait for a bit. >>>>> >>>>> Thanks for advice, >>>>> David >>>>> dgminala at mediacombb dot net >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- [email protected] >>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> ----- >>>>> No virus found in this message. >>>>> Checked by AVG - www.avg.com >>>>> Version: 10.0.1170 / Virus Database: 426/3317 - Release Date: 12/15/10 >>>>> >>>>> >>>>> _______________________________________________ >>>>> time-nuts mailing list -- [email protected] >>>>> To unsubscribe, go to >>>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>>> and follow the instructions there. >>>>> >>>> >>>> -- >>>> "Neither the voice of authority nor the weight of reason and argument are >>>> as significant as experiment, for thence comes quiet to the mind." >>>> R. Bacon >>>> "If you don't know what it is, don't poke it." >>>> Ghost in the Shell >>>> >>>> >>>> Dr. Don Latham AJ7LL >>>> Six Mile Systems LLP >>>> 17850 Six Mile Road >>>> POB 134 >>>> Huson, MT, 59846 >>>> VOX 406-626-4304 >>>> www.lightningforensics.com >>>> www.sixmilesystems.com >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] >>>> To unsubscribe, go to >>>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> and follow the instructions there. >>>> >>>> >>>> _______________________________________________ >>>> time-nuts mailing list -- [email protected] >>>> To unsubscribe, go to >>> >>> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >>>> >>>> and follow the instructions there. >>>> >>> >>> >> >> >> _______________________________________________ >> time-nuts mailing list -- [email protected] >> To unsubscribe, go to >> https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts >> and follow the instructions there. >> > > > > -- > ===== > Chris Albertson > Redondo Beach, California > > _______________________________________________ > time-nuts mailing list -- [email protected] > To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts > and follow the instructions there. > _______________________________________________ time-nuts mailing list -- [email protected] To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
