pretty good frequency counter

Guest
Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.





--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Monday, March 30, 2020 at 10:48:28 PM UTC-4, jla...@highlandsniptechnology.com wrote:
Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.
Click to expand...

I have one I'm not using at the moment. Want me to ship it to you? I expect I can go to a shipper when I go out for groceries tomorrow or the next day. HP 5314-A

--

Rick C.

- Get 1,000 miles of free Supercharging
- Tesla referral code - https://ts.la/richard11209
 
On Mon, 30 Mar 2020 19:48:18 -0700, jlarkin@highlandsniptechnology.com
wrote:

Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.
Click to expand...

This looks OK.

https://www.amazon.com/Precision-1823A-Universal-Frequency-Function/dp/B005J6LP72/ref=sr_1_6?crid=1NZZF2EY5O2PI&dchild=1&keywords=frequency+counter&qid=1585623243&sprefix=frequency+counter%2Caps%2C206&sr=8-6

The B+K stuff is usually pretty good.




--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On 3/31/2020 8:18 AM, jlarkin@highlandsniptechnology.com wrote:
Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.
Click to expand...
*Not* offered as a viable alternative to what you're looking at,
but has anybody fooled around with one of these Chinese 2.4GHz
8-digit modules? - https://tinyurl.com/qv4tfun

I got one last year with the intention of building a usable
counter by adding input stages, power supply, etc., but so far
have never got around to playing with it.
 
On 31/03/2020 03:48, jlarkin@highlandsniptechnology.com wrote:
Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.
Click to expand...

Get a frequency counter with an external 10MHz reference clock input and
use a GPSDO with 10MHz output which you can get for less than $100.

The GPSDO takes a while to stabilise, I just leave it on.

--
Cheers
Clive
 
On 2020-03-31 10:04, George Herold wrote:
On Monday, March 30, 2020 at 10:56:18 PM UTC-4, jla...@highlandsniptechnology.com wrote:
On Mon, 30 Mar 2020 19:48:18 -0700, jlarkin@highlandsniptechnology.com
wrote:


Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.

This looks OK.

https://www.amazon.com/Precision-1823A-Universal-Frequency-Function/dp/B005J6LP72/ref=sr_1_6?crid=1NZZF2EY5O2PI&dchild=1&keywords=frequency+counter&qid=1585623243&sprefix=frequency+counter%2Caps%2C206&sr=8-6

The B+K stuff is usually pretty good.
At PPoE we ditched a (cheaper) B&K counter. The problem for us was
that it didn't actually give the number of pulses, (or rising edges)
in the time window. But it did some sort of unknown averaging, so that
though the average number was correct, there was not enough scatter in the
count number. (This was for a random source... counting pmt pulses.)

For what you want it may be fine.
Click to expand...

I use an HP 5316 for lower frequency and an EIP 578 for up to 18 GHz.
Both cheap on eBay, but don't come with Prime shipping. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
On Monday, March 30, 2020 at 10:48:28 PM UTC-4, jla...@highlandsniptechnology.com wrote:
Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.
Click to expand...

John, I have bought a couple HP HP 5334B counters with the optional 1.3 GHz inputs for under $100.

The most common options:

010 10 MHz OCXO
030 1.3 GHz Channel C
060 Rear panel inputs.

Most selers don't know what they have and miss that the units have these options installed. They have a 10 MHz input, if you have an in house frequency standard. I am working on a GPS derived standard, and some Distribution Amplifiers. They were originally 350 MHz Video DAs that are being converted to 50 Ohms.
 
On Monday, March 30, 2020 at 10:56:18 PM UTC-4, jla...@highlandsniptechnology.com wrote:
On Mon, 30 Mar 2020 19:48:18 -0700, jlarkin@highlandsniptechnology.com
wrote:


Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.

This looks OK.

https://www.amazon.com/Precision-1823A-Universal-Frequency-Function/dp/B005J6LP72/ref=sr_1_6?crid=1NZZF2EY5O2PI&dchild=1&keywords=frequency+counter&qid=1585623243&sprefix=frequency+counter%2Caps%2C206&sr=8-6

The B+K stuff is usually pretty good.
Click to expand...
At PPoE we ditched a (cheaper) B&K counter. The problem for us was
that it didn't actually give the number of pulses, (or rising edges)
in the time window. But it did some sort of unknown averaging, so that
though the average number was correct, there was not enough scatter in the
count number. (This was for a random source... counting pmt pulses.)

For what you want it may be fine.

George H.
--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
Click to expand...
 
On Tuesday, March 31, 2020 at 5:29:48 AM UTC-4, Pimpom wrote:
On 3/31/2020 8:18 AM, jlarkin wrote:

Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.


*Not* offered as a viable alternative to what you're looking at,
but has anybody fooled around with one of these Chinese 2.4GHz
8-digit modules? - https://tinyurl.com/qv4tfun

I got one last year with the intention of building a usable
counter by adding input stages, power supply, etc., but so far
have never got around to playing with it.
Click to expand...

I bought two on Ebay a while back, but I haven't used them yet. I need to pick up some scrap square tubing the frame screen rooms with for cases.
 
On Tue, 31 Mar 2020 11:14:39 +0100, Clive Arthur
<cliveta@nowaytoday.co.uk> wrote:

On 31/03/2020 03:48, jlarkin@highlandsniptechnology.com wrote:

Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.

Get a frequency counter with an external 10MHz reference clock input and
use a GPSDO with 10MHz output which you can get for less than $100.

The GPSDO takes a while to stabilise, I just leave it on.
Click to expand...

We have a high-end GPS source in-house, but it's not run into my
office.

In measuring LC oscillator tempco, something stable to 1 PPM for an
hour would be plenty good. Any counter with a crystal timebase can do
that.

I want to tweak the LC to be +-100 PPM maybe from 0 to 60C, something
like that. It will have a varicap pull range of maybe +-1000. It will
power up at some frequency, doesn't matter much what, and I don't want
it to ever drift out of lock range.

I found a B+K 1823A on Amazon

https://www.amazon.com/gp/product/B005J6LP72/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1

so I ordered one of them. It has ac/dc input coupling and an
adjustable trigger level, so it should be good counting pulses too.

They say they'll deliver to my house on Saturday.





--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On Tuesday, March 31, 2020 at 11:51:33 AM UTC-4, jla...@highlandsniptechnology.com wrote:
On Tue, 31 Mar 2020 07:04:50 -0700 (PDT), George Herold
ggherold@gmail.com> wrote:

On Monday, March 30, 2020 at 10:56:18 PM UTC-4, jla...@highlandsniptechnology.com wrote:
On Mon, 30 Mar 2020 19:48:18 -0700, jlarkin@highlandsniptechnology.com
wrote:


Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.

This looks OK.

https://www.amazon.com/Precision-1823A-Universal-Frequency-Function/dp/B005J6LP72/ref=sr_1_6?crid=1NZZF2EY5O2PI&dchild=1&keywords=frequency+counter&qid=1585623243&sprefix=frequency+counter%2Caps%2C206&sr=8-6

The B+K stuff is usually pretty good.
At PPoE we ditched a (cheaper) B&K counter. The problem for us was
that it didn't actually give the number of pulses, (or rising edges)
in the time window. But it did some sort of unknown averaging, so that
though the average number was correct, there was not enough scatter in the
count number. (This was for a random source... counting pmt pulses.)

For what you want it may be fine.

"Frequency" counters are often AC-coupled with a zero-volts trigger
threshold. They count sine waves fine but are terrible with pulses.
For pulses, you need DC coupling and a settable trigger level.
Click to expand...
Yeah. For pulses it's really nice to have a discriminator where you
can see the input and output to set the threshold.

George H.
--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
Click to expand...
 
On Tue, 31 Mar 2020 07:04:50 -0700 (PDT), George Herold
<ggherold@gmail.com> wrote:

On Monday, March 30, 2020 at 10:56:18 PM UTC-4, jla...@highlandsniptechnology.com wrote:
On Mon, 30 Mar 2020 19:48:18 -0700, jlarkin@highlandsniptechnology.com
wrote:


Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.

This looks OK.

https://www.amazon.com/Precision-1823A-Universal-Frequency-Function/dp/B005J6LP72/ref=sr_1_6?crid=1NZZF2EY5O2PI&dchild=1&keywords=frequency+counter&qid=1585623243&sprefix=frequency+counter%2Caps%2C206&sr=8-6

The B+K stuff is usually pretty good.
At PPoE we ditched a (cheaper) B&K counter. The problem for us was
that it didn't actually give the number of pulses, (or rising edges)
in the time window. But it did some sort of unknown averaging, so that
though the average number was correct, there was not enough scatter in the
count number. (This was for a random source... counting pmt pulses.)

For what you want it may be fine.
Click to expand...

"Frequency" counters are often AC-coupled with a zero-volts trigger
threshold. They count sine waves fine but are terrible with pulses.
For pulses, you need DC coupling and a settable trigger level.



--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
 
On 1/4/20 2:51 am, jlarkin@highlandsniptechnology.com wrote:
On Tue, 31 Mar 2020 07:04:50 -0700 (PDT), George Herold
ggherold@gmail.com> wrote:
The B+K stuff is usually pretty good.
At PPoE we ditched a (cheaper) B&K counter. The problem for us was
that it didn't actually give the number of pulses, (or rising edges)
in the time window. But it did some sort of unknown averaging, so that
though the average number was correct, there was not enough scatter in the
count number. (This was for a random source... counting pmt pulses.)

For what you want it may be fine.

"Frequency" counters are often AC-coupled with a zero-volts trigger
threshold. They count sine waves fine but are terrible with pulses.
For pulses, you need DC coupling and a settable trigger level.
Click to expand...

I investigated the input stages of a good HP frequency counter, because
the cheap one I have is not very reliable, and was quite surprised what
I saw.

There is a huge amount of attenuation first (presumably mostly for
protection) followed by lots of amplification - three stages of
differential ECL or something, I think.

I guess the attenuation ensures that the first amplification stage stays
linear, and the amp provides progressive compression ala a log-amp,
which (it seems to me) should be much better than just zero-crossing
detection. I couldn't see any sign of AGC leading up to the (clamped)
output.

Does that make sense?

Clifford Heath.
 
On 31/3/20 8:29 pm, Pimpom wrote:
On 3/31/2020 8:18 AM, jlarkin@highlandsniptechnology.com wrote:

Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25


I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.


*Not* offered as a viable alternative to what you're looking at, but has
anybody fooled around with one of these Chinese 2.4GHz 8-digit modules?
- https://tinyurl.com/qv4tfun

I got one last year with the intention of building a usable counter by
adding input stages, power supply, etc., but so far have never got
around to playing with it.
Click to expand...

Yes, I have two, one mounted in a little case with a USB power pack. The
module is a clone (from multiple suppliers) of a *hobbyist* project, and
it shows.

The inputs are not very sensitive, and the zero-crossing detector is not
very reliable. If you have a clean signal with adequate and fairly
constant strength you can get a stable reading, but otherwise the
readout will wander around or just lie to you.

The 2.4GHz and 60MHz inputs are both wired to the same input. They work
better if you separate the two inputs. That's a little awkward, because
you have to cut and paste a PCB trace that's sandwiched (near the edge)
under the LED.

They would be just fine with a better input circuit. Buy one with a TCXO.

Clifford Heath.
 
On 2020-03-31 20:43, Clifford Heath wrote:
On 1/4/20 2:51 am, jlarkin@highlandsniptechnology.com wrote:
On Tue, 31 Mar 2020 07:04:50 -0700 (PDT), George Herold
ggherold@gmail.com> wrote:
The B+K stuff is usually pretty good.
At PPoE we ditched a (cheaper) B&K counter.  The problem for us was
that it didn't actually give the number of pulses, (or rising edges)
in the time window.  But it did some sort of unknown averaging, so that
though the average number was correct, there was not enough scatter
in the
count number.  (This was for a random source... counting pmt pulses.)

For what you want it may be fine.

"Frequency" counters are often AC-coupled with a zero-volts trigger
threshold. They count sine waves fine but are terrible with pulses.
For pulses, you need DC coupling and a settable trigger level.

I investigated the input stages of a good HP frequency counter, because
the cheap one I have is not very reliable, and was quite surprised what
I saw.

There is a huge amount of attenuation first (presumably mostly for
protection) followed by lots of amplification - three stages of
differential ECL or something, I think.

I guess the attenuation ensures that the first amplification stage stays
linear, and the amp provides progressive compression ala a log-amp,
which (it seems to me) should be much better than just zero-crossing
detection. I couldn't see any sign of AGC leading up to the (clamped)
output.

Does that make sense?

Clifford Heath.
Click to expand...

Makes perfect sense. The log amp approach prevents the threshold from
changing on the scale of the AGC bandwidth--it responds cycle-by-cycle.

The attenuation of course introduces jitter, but you usually don't care
much in a counter.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
On Monday, March 30, 2020 at 10:48:28 PM UTC-4, jla...@highlandsniptechnology.com wrote:
Anybody have one of these?

https://www.digikey.com/products/en/test-and-measurement/equipment-specialty/618?k=&pkeyword=&sv=0&pv335=349388&sf=0&FV=-8%7C618&quantity=&ColumnSort=0&page=1&pageSize=25

I'll have my new 150 MHz Colpitts LC oscillator test board in a week
or so, and I need a modestly good frequency counter for testing.

We usually buy some high-end Keysight counter/timer for $5K, but I'd
like a cheap, not so exotic counter for my bench.

The LC oscillator has a driven guard, a small ground plane patch,
under the critical nodes. One experiment will be to measure tempco
with that bit grounded, or driven from the emitter of the follower
transistor.

We're still in lockdown, so I'll have to sneak in to build and test
it. Don't tell anybody.





--

John Larkin Highland Technology, Inc

Science teaches us to doubt.

Claude Bernard
Click to expand...

Does your oscilloscope have a counter? I do not hink I have actually ever used a frequency counter. Between having a spectrum analyzer and O-scopes that can measure frequency I have never needed one.
 
Am 01.04.20 um 18:35 schrieb Phil Hobbs:

The attenuation of course introduces jitter, but you usually don't care
much in a counter.
Click to expand...

I have just sold this one, never used in > 4 years:

https://www.ebay.de/itm/202906918438

It can do a lot of stunts that normal counters cannot.


But I will never ever let the Timepod go or the
Stanford SR620.
12 digits in 1 second gate time and ~ 20 ps for time
interval single shot, with the excellent Wenzel time base.

I still have a HP5473, but it is just an array of
intermittent contacts. Takes up valuable rack space.
I have already removed its 10811A time base oscillator.

cheers, Gerhard
 
On 2020-04-01 16:06, Gerhard Hoffmann wrote:
Am 01.04.20 um 18:35 schrieb Phil Hobbs:

The attenuation of course introduces jitter, but you usually don't care
much in a counter.

I have just sold this one, never used in > 4 years:

https://www.ebay.de/itm/202906918438

It can do a lot of stunts that normal counters cannot.
Click to expand...

Yeah, I have a 5372A with the jitter FFT option. A great instrument for
looking at PLL settling and so on, but a big pain to set up, so I don't
use it much either.

Tally-ho

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com
 
On 2/4/20 3:35 am, Phil Hobbs wrote:
On 2020-03-31 20:43, Clifford Heath wrote:
On 1/4/20 2:51 am, jlarkin@highlandsniptechnology.com wrote:
On Tue, 31 Mar 2020 07:04:50 -0700 (PDT), George Herold
ggherold@gmail.com> wrote:
The B+K stuff is usually pretty good.
At PPoE we ditched a (cheaper) B&K counter.  The problem for us was
that it didn't actually give the number of pulses, (or rising edges)
in the time window.  But it did some sort of unknown averaging, so that
though the average number was correct, there was not enough scatter
in the
count number.  (This was for a random source... counting pmt pulses.)

For what you want it may be fine.

"Frequency" counters are often AC-coupled with a zero-volts trigger
threshold. They count sine waves fine but are terrible with pulses.
For pulses, you need DC coupling and a settable trigger level.

I investigated the input stages of a good HP frequency counter,
because the cheap one I have is not very reliable, and was quite
surprised what I saw.

There is a huge amount of attenuation first (presumably mostly for
protection) followed by lots of amplification - three stages of
differential ECL or something, I think.

I guess the attenuation ensures that the first amplification stage
stays linear, and the amp provides progressive compression ala a
log-amp, which (it seems to me) should be much better than just
zero-crossing detection. I couldn't see any sign of AGC leading up to
the (clamped) output.

Does that make sense?

Clifford Heath.

Makes perfect sense.  The log amp approach prevents the threshold from
changing on the scale of the AGC bandwidth--it responds cycle-by-cycle.
Click to expand...

Oooh, way to go, I understood something tricky, the first time, without
bumping my head on it :)

The guy who designed these counter modules went through lots of
iterations to come up with his dual-gate MOSFET setup that still doesn't
work very well. I found the Chinese forum where he posted (and got
feedback on) his earlier versions, and read much of it using Google
Translate.

Someone should clone the design but replace the input with a log-amp...
What's the best chip for that these days?

Clifford Heath.
 
Am 02.04.20 um 04:08 schrieb Clifford Heath:

The guy who designed these counter modules went through lots of
iterations to come up with his dual-gate MOSFET setup that still doesn't
work very well. I found the Chinese forum where he posted (and got
feedback on) his earlier versions, and read much of it using Google
Translate.

Someone should clone the design but replace the input with a log-amp...
What's the best chip for that these days?
Click to expand...

Get the service manual of the Stanford SR620 or HP 5473. (not log)

cheers, Gerhard
 
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