10 Things to Consider When Buying Universal Frequency Counter

Introduction

SUIN contains other products and information you need, so please check it out.

Counters can be a plug-and-play instrument and seem fairly simple from the outside. You connect a signal to the input, and a digital readout tells you the frequency or some other parameter. However, to achieve the best results, whether that means speed or quality, attention to how you set up the counter measurement is important.

Choosing the Best Counter

Selecting which counter will best meet your needs is the first step. There are several related products that perform a variety of tasks at various frequencies:

• Universal counters

Both frequency and time interval measurements, as well as a number of related parameters.

• RF frequency counters

Precise frequency measurements, up to 3 GHz and beyond.

• Microwave frequency counters

Precise frequency measurements, up to 40 GHz and beyond.

• Time interval analyzers

Optimized for precision time interval measurements.

• Modulation domain analyzers

Designed to show modulation quantities, such as frequency versus time, phase versus time, and time interval versus time.

Are you interested in learning more about Universal Frequency Counter? Contact us today to secure an expert consultation!

Hint 1: Recognize the difference between resolution and accuracy 

Assuming a large number of digits equates to a very accurate measurement may not be correct. It is a common mistake to equate resolution and accuracy. They are related, but different concepts. 

The resolution of a counter is the smallest change it can detect in closely spaced frequencies. All other things being equal (such as measurement time and product cost), more digits are better—but the digits you see on the display need to be supported by accuracy. Digits can be deceptive when other errors push the counter’s resolving ability away from the actual frequency. In other words, it’s possible for a counter to give you a very accurate reading of an incorrect frequency. 

Random and systematic errors both determine a counter’s accuracy. Random errors are the source of resolution uncertainties and include: 

• Quantization error 

When a counter makes a measurement, a ±1 count ambiguity can exist in the least significant digit. This can occur because of the non-coherence between the internal clock frequency and the input signal. 

• Trigger error 

Noise spikes can be triggered by noise on the input signal or noise from the input channels of the counter. 

• Timebase error 

Any error resulting from the difference between the actual time base oscillator frequency and its nominal frequency is directly translated into measurement error. 

Systematic errors are biases in the measurement system that push its readings away from the actual frequency of the signal. This group includes effects on the time base crystal such as aging, temperature, and line voltage variations. 

Compare the two counters in Figure 1. Counter A has good resolution but a serious systematic error, so its displayed result in most cases will be less accurate than those of Counter B, which has poorer resolution but a smaller systematic bias error.

0 Members and 1 Guest are viewing this topic.

Contact us to discuss your requirements of Power Quality Analyzer. Our experienced sales team can help you identify the options that best suit your needs.

devanno

• Regular Contributor
• Posts: 83
• Country:
• Old newbie

Universal Counter Suggestions / thoughts

« on: January 09, , 08:15:05 pm » I posted this at the end of an old thread... thought I'd start a new one in case people didn't see the ancient one. :-)

Getting back into the study of electronics after a long hiatus, I am building a test bench for both education and design / repair of "stuff."  It's been noted that the built-into other devices counters aren't always ideal, so I'm looking to add a "universal counter" to my bench.  I realize that these two are not exactly in the same range, but I'm looking at the BK Precision A (which some have indicated that they're quite happy with) and the TTi TF960 (ok, so the 930 would be a better comparison, but if I'm in for that much, might as well go for a bit of gusto).  I am just curious if anyone here has some good insight on these?   TIA...D

P.S.  The other reason I need a universal counter is that I only have 8 fingers and two thumbs, but sometimes, I'm all thumbs. :-)

Free Electrons - Just one, please.

PaulAm

• Frequent Contributor
• Posts: 939
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #1 on: January 09, , 08:42:15 pm » Possibly the ultimate was an HP with a replacement CPU card running Linux.  It ran a emulation, firewall, webserver, etc etc and was tons faster than the original.  It was a pretty neat project.

The original A and B had pretty good specs (20 pS resolution!)  but it really sang with a modern processor.  That counter cost $25K when it came out.

If you search the time-nuts mail archive for " processor board", you'll get the thread.  I'd post the link, but his site does not seem to be up anymore.  Pity that.

BloodyCactus

• Frequent Contributor
• Posts: 482
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #2 on: January 09, , 08:48:55 pm » i have a racal dana I got off ebay for $100 thats fantastic. ovenised oscillator, its a+b inputs can do like 120 or 200mhz and its c input can do 1.5ghz. very sweet piece of kit for 100$ I think its 9 digit plus overflow -- Aussie living in the USA --

kwass

• Frequent Contributor
• Posts: 356
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #3 on: January 09, , 09:36:52 pm »

i have a racal dana I got off ebay for $100 thats fantastic. ovenised oscillator, its a+b inputs can do like 120 or 200mhz and its c input can do 1.5ghz. very sweet piece of kit for 100$ I think its 9 digit plus overflow

I second this.  I got mine off ebay 15 years ago with the 04E oscillator option (high-stability overized oscillator) for about $150.  It's worked perfectly, although some people have had problems with the buttons (search this forum for solutions) I have not.

It's has a 9 digit large LED display but it can overflow and still run, giving you effectively 10 digits.  It's also very flexible once you learn the somewhat quirky way to set options from the front panel.
-katie

babysitter

• Frequent Contributor
• Posts: 899
• Country:
• pushing silicon at work

Re: Universal Counter Suggestions / thoughts

« Reply #4 on: January 09, , 10:26:52 pm » Having a HPA I could give you some insight about that... but what are you looking for ? That info really counts (literally!))
I'm not a feature, I'm a bug! ARC DG3HDA

G0HZU

• Super Contributor
• Posts:
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #5 on: January 10, , 01:21:42 am » Generally speaking, a new and fairly expensive frequency counter isn't something that would be high on the list of priorities for most people. I have never spent more than £80 on a counter and I don't use my counters very often these days. However, I can comment on the two counters you listed....

The TTi uses an LCD display (backlit) and I would suggest you check it out to see if you can live with an LCD display. I prefer counters with a big/bright LED display that can be casually read at an angle at a distance. But that's just me...

Both of the counters offer remote logging. One is RS-232 and one is USB. I do think this could prove a useful feature if you wanted to log the drift of something over time.

But here is a slight problem with both of these reciprocal counters... Compared to older/used/cheaper high end instruments they are both slow in terms of measurement/display time for a 9 digit display. eg 10 seconds measurement time?  So you could only get (fresh) data at this resolution every 10 seconds.

This is fine for most applications but I'd be seriously pissed off if I'd spent £400 on a new/modern counter that was this slow.

For home use most people would be better off buying something like an old Racal reciprocal counter/timer for a fraction of the price (but it will be just as slow) although I would try and get one with GPIB for logging. But a lot depends on what you plan to do with the counter. « Last Edit: January 10, , 01:49:00 am by G0HZU »

devanno

• Regular Contributor
• Posts: 83
• Country:
• Old newbie

Re: Universal Counter Suggestions / thoughts

« Reply #6 on: January 10, , 04:56:24 am » Thanks all for the quick replies.  I was looking on eBay, actually, and perhaps wasn't looking closely enough.  :-)  I really appreciate the thoughts and input!!!

As for the -exact- use, I'm not 100% sure yet.  Mostly doing some self education and assembling a bit of decent kit while I can afford it.  I'm kind of front ending the funding of some "hobby" items in my retirement. 

Again, many thanks! Free Electrons - Just one, please.

Vgkid

• Super Contributor
• Posts:
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #7 on: January 10, , 05:17:03 am » I'll echo babysitters response, and say that the A is another contender. If you own any North Hills Electronics gear, message me. L&N Fan

oldway

• Super Contributor
• !
• Posts:

Re: Universal Counter Suggestions / thoughts

« Reply #8 on: January 10, , 08:19:41 am » I have an HPA with options 001 (TCXO) and 003 (C channel 50 to Mhz) and I am very satisfied with it.

Re: Universal Counter Suggestions / thoughts

« Reply #9 on: January 10, , 08:32:52 am » I recon this Philips one is a good buy, it's a really nice bit of kit:
http://www.ebay.com.au/itm/PM-PHILIPS-HIGH-RESOLUTION-PROGRAMMABLE-TIMER-COUNTER-225MHz-/
Only the standard internal oscillator though.
They usually go for much more than this.

Re: Universal Counter Suggestions / thoughts

« Reply #10 on: January 10, , 08:35:36 am » Also the Philips is great small size unit.
Once again, if you can get one at a decent price with an oven oscillator then it's a good score.

engiadina

• Contributor
• Posts: 45
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #11 on: January 10, , 09:20:55 am » Let me add the HP a with at least option 001 (mid stability oszillator).

You might eventually find this for a decent price.


From my own experience go for HP, Phlips/Fluke, Racal
I checked a Hameg counter ... guessing would gave been more exact. Timebase stability was atrocious.

Guido

babysitter

• Frequent Contributor
• Posts: 899
• Country:
• pushing silicon at work

Re: Universal Counter Suggestions / thoughts

« Reply #12 on: January 10, , 01:41:24 pm » Help us a little bit:

Do you want to count frequencies above what you can use a scope for, or do you want way higher resolution that possible with peak-counting on the scope?
Do you want to measure one or several events that are too slow for convenient o-scope-peak-counting?
Do you want to log frequencies or time-intervals?

If you answer at least one of those with yes, then go for Universal counter.
Consider using a wide-band radio receiver as an alternative for high frequency stuff, you might be able to listen into your signal. Google for SDR dongle.

If you want to do digital stuff, consider a Logic analyzer (OpenBench LA for example), you can read the frequency and time intervals with that device, too.

If you want the convenience of connect to DUT and read frequency, go for Unicounter.

You should be able to get decent offers on ebay or other places where cleanout of labs appear, at a nearby ham radio swap I saw the younger brother of mine recently, the HPB.

If you only want frequency reading, a simple frequency counter is enough, a universal counter will help if you want to compare frequencies or have exotic trigger/arming requirements for example.

About everything you can do with a UC you can do with other stuff, e.g. adjusting the LO of a radio to a known good source of LO Frequency ? Wideband radio, Lissajous method on cheaposcope are available too. But without the convenient number readout.

I like my Box A, but there are other from HP and there are also other manufacturers of course who make decent rigs.

What upper frequency limit do you look for ?

Check your space constraints, means check what fits best on your desk.

Get the manuals matching the offers on ebay for example from KO4BBs website, compare specifications.
A bad mother oscillator is not a no-go - you can replace it with something better.
A defect box is always a gamble, mine had defect not listed but was way cheaper than the others.
"only" had series resistors in input stages burnt, easy to replace. Mother oscillator seems to have been a Hameg , so I stuck a OCXO from ebay in it. Works like a charm.

« Last Edit: January 10, , 01:44:59 pm by babysitter » I'm not a feature, I'm a bug! ARC DG3HDA

jpb

• Super Contributor
• Posts:
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #13 on: January 10, , 03:04:37 pm » I have the TTi TF930 which I bought as an ex-demo unit for £200.

The reasons I went for it was I wanted 10 digits and I wanted a counter that would go down below 1 Hz and have a reference input so I could stick my 10MHz reference on the reference input and measure the 1pps from a GPS module and then tune my 10MHz source.

For this purpose the TTi TF930 works well. Other pluses are it is a continuous reciprocal counter (i.e. it doesn't reset itself between readings but continues to count), it is very light and low power so it can operate from USB or from its internal batteries and it is very easy to carry around.

The negatives are the LCD display isn't even backlit so is not easy to see in some conditions and it is a bit slow if you want the full 10 digits (i.e. you need to set the 100 second gate).

As others have said, you can get good 8 digit or 9 digit counters with bright displays more cheaply on e-bay which are probably a better choice for direct frequency measurement. I personally didn't go for these because they tend to have a minimum frequency of several 10s of Hz and I already have 6 digits on my scope counter so I wanted a significant step up from this.

What I'd really like is one of top-of-the-line Agilent series at 12 digits a second and 20 psec resolution but these are ten times the price even second hand.

EDIT: another negative, which rather annoys me, is that the 10MHz reference input requires quite a high amplitude (at least 1Vrms I think) to be recognized so I had to build a little video amp just to get my 10MHz OCXO to become a reference source and you can't take the reference output of  say the Agilent A and feed it straight into the reference input of the TTi. There is also no reference output so it is difficult to daisychain.

Another plus though is that it can be connected to a computer for logging readings and so on, but I've only managed to do this successfully using a dumb terminal on a Windows XP laptop - I've not yet managed to get it talking to my Windows 7 64bit workstation. I've not tried for a while though, TTi may have produced an updated driver. « Last Edit: January 10, , 03:16:39 pm by jpb »

devanno

• Regular Contributor
• Posts: 83
• Country:
• Old newbie

Re: Universal Counter Suggestions / thoughts

« Reply #14 on: January 10, , 04:36:18 pm »

Help us a little bit:

Do you want to count frequencies above what you can use a scope for, or do you want way higher resolution that possible with peak-counting on the scope?

Higher resolution, easier to set up or to use when I need the 'scope(s) for other measurements

Quote

Do you want to measure one or several events that are too slow for convenient o-scope-peak-counting?

A definite possibility.

Quote

Do you want to log frequencies or time-intervals?

Unsure at this juncture.

Quote

If you answer at least one of those with yes, then go for Universal counter.

Thanks!  You just confirmed my thinking! 

Quote

Consider using a wide-band radio receiver as an alternative for high frequency stuff, you might be able to listen into your signal. Google for SDR dongle.

Oh... now that's a cool thought!  Will keep this in mind.

Quote

If you want to do digital stuff, consider a Logic analyzer (OpenBench LA for example), you can read the frequency and time intervals with that device, too.

I have a USB logic analyzer that will work for now.


Quote

You should be able to get decent offers on ebay or other places where cleanout of labs appear, at a nearby ham radio swap I saw the younger brother of mine recently, the HPB.

Am currently eyeing an HPA with the OCXO at the moment.  A bit pricey, but I like the OCXO option, and I think the extra few bucks is worth the time stability.  I may also want to use the output from that XO as input to other instruments for some tests, just to insure that all are on the -same- time base.

Quote

If you only want frequency reading, a simple frequency counter is enough, a universal counter will help if you want to compare frequencies or have exotic trigger/arming requirements for example.

About everything you can do with a UC you can do with other stuff, e.g. adjusting the LO of a radio to a known good source of LO Frequency ? Wideband radio, Lissajous method on cheaposcope are available too. But without the convenient number readout.

I like my Box A, but there are other from HP and there are also other manufacturers of course who make decent rigs.

What upper frequency limit do you look for ?

Check your space constraints, means check what fits best on your desk.

Get the manuals matching the offers on ebay for example from KO4BBs website, compare specifications.
A bad mother oscillator is not a no-go - you can replace it with something better.
A defect box is always a gamble, mine had defect not listed but was way cheaper than the others.
"only" had series resistors in input stages burnt, easy to replace. Mother oscillator seems to have been a Hameg , so I stuck a OCXO from ebay in it. Works like a charm.

So.. not sure what upper Freq I'll eventually need, but for now, 200MHz will do.  I was only looking at the higher priced spread because if I was going to buy new, I was just going to go for "one."   All the great replies here forced me to do more research on eBay.  Oh, and I have the manuals downloaded for the HPA/B and the HP already, too.

Thank you once again! Free Electrons - Just one, please.

devanno

• Regular Contributor
• Posts: 83
• Country:
• Old newbie

Re: Universal Counter Suggestions / thoughts

« Reply #15 on: January 10, , 04:38:23 pm » JPB ... thanks for that review.  I guess I missed the "no backlight" part, and that's likely a killer for me on that unit.  Looking now at an HP A with OCXO on eBay.

To all:  thank you, thank you, thank you!  You've really got me pointed in what I think is the right direction here! Free Electrons - Just one, please.

G0HZU

• Super Contributor
• Posts:
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #16 on: January 10, , 06:06:07 pm » Quote

You've really got me pointed in what I think is the right direction here!

Are you sure about that?

The HPA is a huge thing and I wouldn't have one of these counters even for free simply because it takes up too much space for what it can offer me in return. I'm guessing it has a fan (so it would also be noisy and annoying to use) and presumably it takes a fair bit of power as well. It's the kind of thing that appeals to timenuts who don't care how much space or power it needs or how noisy and annoying it is to use because it has a high spec and lots of digits. That's all that matters to them.

Something like the little Racal /2 that was mentioned earlier is fairly small and can be easily stashed out of the way when not in use. I have an old Philips PM 1.3GHz reciprocal counter/timer here with the dreaded LCD display but it is a far better choice compared to the big old HP as long as you can live with 8 digits per second measurement time (or 9 digits per 10 seconds). It is a nice little compact unit that can be moved around easily from room to room or shelf to bench or you can plonk it on top of something easily.

Try to do that with an HP... 
« Last Edit: January 10, , 06:25:49 pm by G0HZU »

orin

• Frequent Contributor
• Posts: 445
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #17 on: January 10, , 07:22:17 pm » A will give 9 1/2 digits in less than 2 seconds.  It plonks down fine on top of an A spectrum analyzer   And also supports the laptop that sits on top of it...

However, a A will likely need a little work.  See the service note I posted in a different thread.  If it has the AC fan, you'll want to replace it with a 24V DC fan as per the service note (plenty of 24V 80mm x 80mm fans out there to chose from).  If it already has the DC fan and the wiring described in the service note has not been done, you'll want to replace the relay socket and do the extra wiring or one day, you'll turn it on, the fan will run, but there will be no display.

orin

• Frequent Contributor
• Posts: 445
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #18 on: January 10, , 07:30:41 pm »

Possibly the ultimate was an HP with a replacement CPU card running Linux.  It ran a emulation, firewall, webserver, etc etc and was tons faster than the original.  It was a pretty neat project.

The original A and B had pretty good specs (20 pS resolution!)  but it really sang with a modern processor.  That counter cost $25K when it came out.

If you search the time-nuts mail archive for " processor board", you'll get the thread.  I'd post the link, but his site does not seem to be up anymore.  Pity that.

It's working for me:

http://www.jks.com//.html

Also:

https://github.com/jks-prv/_proc

I don't know if there are still boards available.

G0HZU

• Super Contributor
• Posts:
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #19 on: January 10, , 07:54:17 pm » Quote

A will give 9 1/2 digits in less than 2 seconds.

Some of the little Racal reciprocal counters will do 9 digits per second and they are a tiny fraction of the size of that big old monster from HP.

I have an old japanese counter here (mid s vintage) that is even faster and it only cost me £65 and has a smaller front area than the Racal. The HPA is a big old thing that is best suited to diehard timenuts who will probably only ever feed it a 10MHz signal from their various references (whilst keeping a box of tissues handy).

There are far more practical and realistic choices for the typical person who just wants to do a few repairs and learn some electronics. But I suspect my advice will go unheeded. It usually does on this forum 

« Last Edit: January 10, , 07:56:53 pm by G0HZU »

bingo600

• Super Contributor
• Posts:
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #20 on: January 10, , 11:03:19 pm »

Possibly the ultimate was an HP with a replacement CPU card running Linux.  It ran a emulation, firewall, webserver, etc etc and was tons faster than the original.  It was a pretty neat project.

The original A and B had pretty good specs (20 pS resolution!)  but it really sang with a modern processor.  That counter cost $25K when it came out.

If you search the time-nuts mail archive for " processor board", you'll get the thread.  I'd post the link, but his site does not seem to be up anymore.  Pity that.

Try
http://www.jks.com//.html


I have one 

Ohh ...
And a Racal , and a PMB and .... 

/Bingo « Last Edit: January 10, , 11:07:33 pm by bingo600 »

G0HZU

• Super Contributor
• Posts:
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #21 on: January 11, , 12:16:31 am » How about this HPA on youtube.



Check out the loud buzzing noise from the worn out fan (especially at 3:57 onwards  )

It's a big old ATE counter designed to be put in a rack where humans don't tread or listen to the rack noise or have to put up with that hideous user interface. It's mainly meant to be remotely controlled by a computer in an ATE rack system and not sat in someone's bedroom measuring the clock frequency of an Arduino board or a typical ham/CB radio.

Maybe I should try a bit of reverse psychology and recommend that somebody who doesn't yet know why they need a counter or what they will use it for should always buy the biggest, noisiest counter they can find with 12 display digits and the most complicated and badly planned user interface. It should also weigh about 5 times more than a regular counter, consume at least ten times as much power as a regular counter (so they can enjoy having it on all day in a small room in the summer?) and it should be about 35 years old and fairly unreliable and should take up a huge and deep area of the workbench. Then they can sit back and enjoy... « Last Edit: January 11, , 12:21:29 am by G0HZU »

devanno

• Regular Contributor
• Posts: 83
• Country:
• Old newbie

Re: Universal Counter Suggestions / thoughts

« Reply #22 on: January 11, , 06:15:57 am »

How about this HPA on youtube.



Check out the loud buzzing noise from the worn out fan (especially at 3:57 onwards  )

It's a big old ATE counter designed to be put in a rack where humans don't tread or listen to the rack noise or have to put up with that hideous user interface. It's mainly meant to be remotely controlled by a computer in an ATE rack system and not sat in someone's bedroom measuring the clock frequency of an Arduino board or a typical ham/CB radio.

Maybe I should try a bit of reverse psychology and recommend that somebody who doesn't yet know why they need a counter or what they will use it for should always buy the biggest, noisiest counter they can find with 12 display digits and the most complicated and badly planned user interface. It should also weigh about 5 times more than a regular counter, consume at least ten times as much power as a regular counter (so they can enjoy having it on all day in a small room in the summer?) and it should be about 35 years old and fairly unreliable and should take up a huge and deep area of the workbench. Then they can sit back and enjoy...

      All I can say is that I will not be in a quiet environment most of the time... my shop is in the "mechanical room" in my basement with the water heaters, furnace, sump pumps, etc.  It's dry, but it's not quiet.  Since I'm old and getting hard of hearing, no problem there!  :-)   Seriously, though, one side of my bench is 18" deep shelves... the horizontal space is not so much of an issue, and I can replace fans.  I wonder if that guy in the You Tube video had baseball cards stuck to the fan with clothes pins.  (You have to be old, and possibly from the US of A to get that one, sorry.)  That unit is in definite need of some TLC for sure.  As for kludge interfaces, heck, I spent over 42 years in information technology... I've seen, learned and worked with my share.   This isn't a done deal, and I appreciate your thoughts and input. Free Electrons - Just one, please.

devanno

• Regular Contributor
• Posts: 83
• Country:
• Old newbie

Re: Universal Counter Suggestions / thoughts

« Reply #23 on: January 11, , 06:18:16 am »

A will give 9 1/2 digits in less than 2 seconds.  It plonks down fine on top of an A spectrum analyzer   And also supports the laptop that sits on top of it...

However, a A will likely need a little work.  See the service note I posted in a different thread.  If it has the AC fan, you'll want to replace it with a 24V DC fan as per the service note (plenty of 24V 80mm x 80mm fans out there to chose from).  If it already has the DC fan and the wiring described in the service note has not been done, you'll want to replace the relay socket and do the extra wiring or one day, you'll turn it on, the fan will run, but there will be no display.

Thanks for the heads-up on the service note.  I'll search for it.    Free Electrons - Just one, please.

G0HZU

• Super Contributor
• Posts:
• Country:

Re: Universal Counter Suggestions / thoughts

« Reply #24 on: January 11, , 03:04:54 pm » At the end of the day only you can decide what is right for you

I can only offer general advice. That A counter would typically have been used by a manufacturer of time/frequency related
products in a test/dev area where it could have been used for things like critically analysing the performance of new OCXO or clock generator designs over temperature, time and shock/vibration. eg it would have been used to gather critical performance data over the course of hours/days/weeks using an automated system. presumably the results of this would make their way onto the manufacturer's datasheet for the OCXO when it gets released for production/sale.

Maybe you feel you have a need for this level of performance but the advice I can offer is to 'not' be seduced by the performance it offers because it comes at the price of size, weight, power, reliability, ease of use and ease and cost of maintenance.

Measuring frequency (accurately?) beyond about 8 or 9 digits doesn't really add much value for the vast majority of professional or hobby users.

If you do buy it then it's worth finding out how long it takes for the OCXO to warm up and also if it stays hot in standby. I would assume it does stay hot in standby. My old Anritsu counter has a huge and very expensive Toyo OCXO inside it and it takes about 50 minutes to stabilise. This is a major PITA and for this reason I usually use it with an external OCXO I put in a small diecast box. This is a newer generation OCXO that has a 4 minute warmup time and you can buy used OCXOs like this on ebay for maybe $15-$25. A typical OCXO like this would deliver about 0.01ppm performance in a typical lab/workroom environment for many months before it aged and required a recal. My little external OCXO usually stays within about 0.03Hz of 10MHz for many months. So that makes it ideal for getting the best from an 8 or 9 digit counter and it warms up to very close to this level of performance in about 4 minutes.