[time-nuts] Frequency counter recommendation

Fri Dec 17 02:53:42 UTC 2010

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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>>>
>>> --
>>> "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
>>>
>>>
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>
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-- 
=====
Chris Albertson
Redondo Beach, California