[time-nuts] Frequency counter recommendation

Fri Dec 17 09:18:01 UTC 2010

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 <bownes at 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.chris at 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
>>> 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 <alanh137 at comcast.net>
>>> 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: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]
>>>>> 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<lists at rtty.us>  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: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com]
>>>>>> 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: time-nuts-bounces at febo.com
>>>>>>> [mailto:time-nuts-bounces at febo.com]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
>>>>>>>
>>>>>>> _______________________________________________
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>>>>>>> _______________________________________________
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>>>>>>>
>>>>>>
>>>>>> --
>>>>>> "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 -- time-nuts at febo.com
>>>>>> To unsubscribe, go to
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>>>>>>
>>>>>>
>>>>>> _______________________________________________
>>>>>> time-nuts mailing list -- time-nuts at febo.com
>>>>>> To unsubscribe, go to
>>>>>
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>>>>>>
>>>>>> and follow the instructions there.
>>>>>>
>>>>>
>>>>>
>>>>
>>>>
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>>>
>>>
>>>
>>> --
>>> =====
>>> Chris Albertson
>>> Redondo Beach, California
>>>
>>> _______________________________________________
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>>
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>
>
>
> --
> =====
> Chris Albertson
> Redondo Beach, California
>
> _______________________________________________
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-- 
"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