No subject

highest priority since I tend to be interested in phase differences between
signals.   If I was dealing with phase drift of frequencies much above 1Hz,
I'd probably add some sort of stable frequency divider, probably based on
picdiv if the frequency of interest was still low enough.

If I just needed absolute frequency and not a phase I might consider some
other device which would take the 10mhz reference. Depending on the
accuracy needed this might even be some dirt cheap old counter which uses a
traditional "count pulses/cycles between gate triggers".  Dividing a
relatively high accuracy 10mhz clock from a GPSDO down to 1hz and using
that as a gate on a suitably big counter would get you to approximately 1
Hz resolution.   I'm not a big frequency nut so I don't have a lot of
experience here.




On Mon, Mar 13, 2023, 7:39 PM John Miller via time-nuts <
time-nuts at lists.febo.com> wrote:

> Hi Bob,
> Lots of interesting info here, for sure. To start, I'll clarify and answer
> the first four questions:
>
> - How good is good? I don't really know - a lot of this depends on how
> much I have to spend. I got my Ramsey CT-125 for $30, and it's great, but
> can't perform any analysis. How about "trustworthy measurements in the
> range of 1-5ns".
>
> - Budget? I'd like to stay under $250, unless an incredible option comes
> along for not much more. I'm basing that on two things: 1) what I have seen
> 5334s and 5335s sell for, and 2) how much I can usually reasonably allocate
> to hobbies.
>
> - How soon do I want it? I've been getting progressively deeper into
> "TimeNuttery" over the past 3-4 years, so I'm fine waiting 6-12mo for the
> right piece of gear to come along - I just want to know what to look for.
>
> - How much effort? I'm willing to put in a lot of effort as long as there
> is a light at the end of the tunnel. I have plenty of experience replacing
> mundane components in older gear (RTC batteries, tag tantalum caps, carbon
> resistors, etc.) so minor work doesn't scare me off. However, the $150
> 5386A that "just" needs a prescaler? Yeah, I know how that goes - it sits
> in a closet for two years and I end up buying another functioning 5386A for
> $350.
>
> I am very interested in home brew projects, especially if it's something I
> can build myself. I am aware of the TAPR TICC, and similar time interval
> counter projects, but I'm also interested in a "general purpose" counter
> that can be used to, say, characterize an oscillator in another piece of
> equipment.
>
> If I could find a 5334 for $50, I'd probably jump on it right away.
> Looking at recently sold on ebay currently places working 5334Bs closer to
> the $150 mark, and 5335As around the $250 mark. Prices on old gear have
> started to climb again.
>
> John
>
> > On Mar 13, 2023, at 5:24 PM, Bob Camp <kb8tq at n1k.org> wrote:
> >
> > Hi
> >
> > This pretty quickly gets into “how good is good?”, “what’s the
> budget?”,  “how quick do you need it?”,
> > and “how much effort do you want to sink into this?”.
> >
> > If you have the time to shop, eBay can and does turn up some “finds”.
> When those pop up, they
> > likely will not hang around all that long. The more common listings at 3
> or 10X the magic price will
> > indeed keep hanging around for a long time.
> >
> > Indeed HP / Agilent / Keysight isn’t the only game in town. The SRS 620
> is still a pretty good beast.
> > There are various “home brew” projects out there that compete quite well
> with a number of the counters
> > mentioned above.
> >
> > So, what happens as you move along?
> >
> > The 5334 / 5335 generation machines came in at a nanosecond or two sort
> of resolution. Their competitors
> > might have pushed a couple more ns into that budget in the same era.
> Typically they are big boxes with
> > GPIB interfaces. The 5345 / 5360 / 5370 go back to the same time frame,
> but generally give you more resolution.
> > Still the same big box / GPIB setup.
> >
> > How well is something this old likely to work? Those displays are pretty
> old and getting harder to find. There
> > are some unique front end stuff in them that can be tough to repair (
> put 5V into the 5335 and there goes the
> > front end on 1X attenuation / DC coupling ….).
> >
> > Next up are the 5313x machines. They get you a serial output that should
> work for logging. They also are a
> > bit smaller. Power supplies typically are their weak point.  Resolution
> is in the 100 to 400 ps range depending
> > on model and how picky you are.
> >
> > While it seems crazy, the 5323x generation has been out long enough to
> be bouncing around eBay. You add
> > an ethernet interface to the mix. Resolution goes down into the 10’s of
> ps. Don’t count on using the ref out
> > for anything ….
> >
> > Price?
> >
> > The 5334 should be a sub $50 item by now and the 5335 still under $100.
> The 5313x generation should come
> > in below $300. The 5323x generation should be below $1500. Yes, you can
> easily find all of these for 5X
> > those prices.
> >
> > All that and we haven’t even begun to talk about frequency range, or
> what you want to use it for.
> >
> > Bob
> >
> >
> >> On Mar 13, 2023, at 2:26 PM, John Miller via time-nuts <
> time-nuts at lists.febo.com> wrote:
> >>
> >> Hey All,
> >> Long ago I reached the point where I really need to get my hands on a
> real frequency counter, but I was able to work around with with
> cobbled-together solutions. Now I have started a new project and I need
> something trustworthy that I can rely on for good measurements. I'm looking
> for something "general purpose" that can also do time interval measurements
> as well as logging, be it to GPIB, serial, USB, whatever. The ability to
> operate off of an external timebase would be nice, too, since I do have a
> known-good rubidium oscillator.
> >>
> >> The HP 5334B and 5335A are good options, but I have some anxiety about
> buying older equipment from ebay that may be in rough shape or questionable
> provenance. That said, I suspect that there are other reputable options out
> there, and I want to keep my mind open. I'm not biased towards old or new
> or any particular brand, but I would like to keep the cost under a couple
> hundred dollars.
> >>
> >> Anyways, I figured if anyone could get me some recommendations, it
> would be you guys! (And of course if anyone here has one they want to sell,
> let me know!)
> >>
> >> Thanks in advance,
> >> John M.
> >> KC1QLN
> >> _______________________________________________
> >> time-nuts mailing list -- time-nuts at lists.febo.com
> >> To unsubscribe send an email to time-nuts-leave at lists.febo.com
> _______________________________________________
> time-nuts mailing list -- time-nuts at lists.febo.com
> To unsubscribe send an email to time-nuts-leave at lists.febo.com