[time-nuts] Re: Frequency counter recommendation wanted

[John Miller]

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
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