Hi

Erik - an excellent low cost design - very well done!

I am interested in measuring to CISPR11 for EMC pre-compliance testing on Industrial RF equiment.

Would it be at all possible to implement the CISPR 16 Resolution Bandwidths please?

These are:

9 kHz to 150 kHz (Band A), RBW = 200 Hz
150 kHz to 30 MHz (Band B), RBW = 9 kHz
30 MHz to 300 MHz (Band C), RBW = 120kHz
300 MHz to 1,000 MHz (Band D), RBW =120kHz

Also, does anyone know of a low cost calibrated Antenna which can measure from 20MHz to 1000MHz?

I have a very large and expensive Sunol Log Periodic Antenna which covers up to 5gHz and is calibrated, but I was rather hoping that eventually a more portable calibrated antenna might become available.

Thanks

Tony

On Sat, Nov 19, 2022 at 10:12 AM, <koralrf@...> wrote:

Would it be at all possible to implement the CISPR 16 Resolution Bandwidths

The options for random RBW are not available

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Hello Eric,

The CISPR 16 RBW requirements are quite specific.
Since RBW is implemented in software, it would be relatively easy to implement on the the TinySA and/or the ULTRA.
You and Hugen a probably flat out satisfying demand already, but the inclusion of the 9KHz and 120KHz RBWs would certainly make the instruments highly desirable for EMC pre-compliance testing.

Unfortunately, RBW modifications can't be implemented in post processing later.

Don't know if you would be interested in running a poll.

Regards...Bob VK2ZRE

On Sat, Nov 26, 2022 at 10:13 PM, Bob Ecclestone wrote:

Since RBW is implemented in software, it would be relatively easy to implement on the the TinySA and/or the ULTRA.

Bob,
The RBW is implemented by the chip manufacturer in embedded DSP code that can not be modified and there? is only a limited set of parameters you can modify to steer this code.
I will have a look but I'm afraid it will not be possible to have exactly the specified RBW.
Even with approximated RBW I know many people are successfully using the tinySA in EMC pre-compliance as the differences are small. Try to calculated the difference in dB when measuring a wide band source
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On Sat, Nov 26, 2022 at 10:13 PM, Bob Ecclestone wrote:

Hello Eric,

The CISPR 16 RBW requirements are quite specific.
Since RBW is implemented in software, it would be relatively easy to implement on the the TinySA and/or the ULTRA.
You and Hugen a probably flat out satisfying demand already, but the inclusion of the 9KHz and 120KHz RBWs would certainly make the instruments highly desirable for EMC pre-compliance testing.

Unfortunately, RBW modifications can't be implemented in post processing later.

Don't know if you would be interested in running a poll.

Bob,
? For final compliance testing using the specified CISPR-16 RBW is mandatory but for pre-compliance testing, when using a spectrum analyzer versus an EMC receiver, you can get away with a 10k or 100k RBW versus a 9k or 120k RBW.? You definitely want to try to give yourself a 6-10dB margin to the limit during pre-compliance testing and you can also add a bandwidth correction factor to your measured value to get a more accurate measurement.

? I wouldn't trust the Quasi-peak measurement function until it has been verified by an EMC expert. Also, ensure you have enough measurement points that your tinySA step size is at least half your RBW.

? There is an opportunity for an enterprising software developer to create a pre-compliance EMC software app for the tinySA Ultra that adds in transducer (i.e. antennas, LISN's) factors, correction (i.e cable loss, pre-amp) factors, and implements plotting functions.

Herb

On Sun, Nov 27, 2022 at 03:11 AM, hwalker wrote:

Also, ensure you have enough measurement points that your tinySA step size is at least half your RBW.

This is always guaranteed in the tinySA
If you choose a any amount of measurement points and span the tinySA will insert hidden measurement points to ensure step size <= RBW/2 if needed.?
?
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On Sun, Nov 27, 2022 at 05:57 AM, Erik Kaashoek wrote:

On Sun, Nov 27, 2022 at 03:11 AM, hwalker wrote:

Also, ensure you have enough measurement points that your tinySA step size is at least half your RBW.

This is always guaranteed in the tinySA
If you choose a any amount of measurement points and span the tinySA will insert hidden measurement points to ensure step size <= RBW/2 if needed.?

Erik,
? Is that also true when using tinySA-App? I notice step-size is calculated in the app status panel based on frequency span and number of points selected.

Herb

tinySA-App uses scanraw thus ensuring no gaps and 50% overlap.
This displayed step size is for information only
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Hello Erik and Group,

Erik, thanks for the info regarding the DSP code.

And thanks to the other posters on this subject. It is good to know there is an active EMC testing cohort out there.
I guess I need to remember that it is PRE-COMPLIANCE testing and that the RBW errors are indeed small.
When I was in the industry developing product, we always aimed for a minimum 6-10dB headroom at the development stage.
That way, we generally managed first pass testing during manufacturing.
I have been out of the game for many years now but still like to follow what is happening.

The TinySA and the new Ultra are amazing pieces of kit. Thank you so much for these great little gems Erik.

73...Bob VK2ZRE

How to set RBW to 200Hz?

See:?https://tinysa.org/wiki/pmwiki.php?n=TinySA4.MenuTree
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On Sun, Mar 24, 2024 at 09:30 AM, Erik Kaashoek wrote:

https://tinysa.org/wiki/pmwiki.php?n=TinySA4.MenuTree

Ok, but my version is 1.4.142 and minimum is 3kHz.

you can use lower RBW, just the measurement may be slower.?

"you can use lower RBW, just the measurement may be slower. "

Yes, but the idea is to make the measurement compliant with the CISPR standard.

For precompliance measurements the build in 200 Hz, 10 KHz and 100kHz RBW are close enough.
Of course not for true compliance measurements?

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On Sun, Mar 24, 2024 at 07:04 PM, Erik Kaashoek wrote:

For precompliance measurements the build in 200 Hz, 10 KHz and 100kHz RBW are close enough.

I'd agree.

It's exactly that, pre-compliance testing, and it's good enough to highlight any problem areas.

Even in the past, when I've performed pre-compliance tests with suitable equipment, there was still some variation from when measured in a certified lab environment.

You need to leave some margin, and if it's that close to failing, you maybe have to implement a design revision to ensure getting it through.

Regards,

Martin

For precompliance measurements the build in 200 Hz, 10 KHz and 100kHz RBW are close enough.Of course not for true compliance measurements

Yes, I know that, but the RBW 200Hz is probably only available in the ULTRA version?

I have built a TEM-CELL based on the TBCT1 dimensions from TEKBOX and am slowly trying to measure something on it.