At the risk of adding more noise to the discussion I suspect there is a question of perspective.? EMC/RFI compliance is expensive.? Commercial grade test equipment to do EMC/RFI compliance is expensive.? The TinySA is cheap, but huge value for the cost.

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If you are self funded or working for small company on a limited budget then the cost of a precompliance scan is expensive in most countries.? So the desire to do some self testing before using a lab is understandable, even if it is probably misguided.? I'm tempted to do exactly that on a project I am working on now, but I realise the short comings in my environment you probably make it not worth the effort, so will probably recommend a precompliance scan with a local lab (600km away).? Then use the TinySA to narrow down the source of any potential failure frequencies and evaluate fixes.? The full compliance test will probably be done in China by a suitably certified lab recommend buy our trusted manufacturing partner there.

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So while people here hold strong views and are not shy in expressing them it does help to remember that many buyers of a TinySA will have different views on what is expensive and what is cheap and therefore different motivations about how to do testing.

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Cheers

? David ZL2DAA

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It always distresses me when people who are obviously very clever and experienced refuse to afford the politeness and assistance that they were no doubt offered when they were beginning in a field. You don't have to be rude in order to prove your superior intelligence. But there, clearly I expect too much of humanity. AI will not doubt do better.

I often wonder if people expect more from this device than it is capable of. I am not sure exactly what the OP wants to do, but maybe there are other devices or equipment that can do it better. The TinySA Ultra is an amazing piece of equipment and I have used it several times to peak the pipe cap filters for output in the 10 to 12 GHz range for the W1GHZ microwave frequency multiplier designs. This is something I can't do with an HP 435B power meter by itself. The TinySA shows me what frequency the output is at. Tuning these pipe cap filters with a power meter alone sometimes results in tuning to the wrong harmonic. But I wouldn't trust the accuracy of the power output measurement. Once I have the pipe cap filters peaked, I can measure the power for accuracy with the 435B. And I wouldn't trust the frequency measurement to be extremely accurate. I have an EIP frequency counter that will measure frequency accurately down to the Hz in the range of LF to 18 GHz. Also, you can't accurately measure the NF of a microwave preamp with the TinySA.

Zack W9SZ

On Mon, Feb 3, 2025 at 12:10?PM W0LEV via <davearea51a=[email protected]> wrote:

Since you know nothing about this system, you are biting off something WAY OVER YOUR HEAD.? You might be able to do a pre-compliance assessment, but that's all.? And.....you need to learn the ropes of making radiated and conducted emission measurements in a responsible and best -practices manner.? If you are also looking at the EU, there are a whole bunch of additional required tests addressing the susceptibility side of things.? A crash course from one of the few consultants giving classes on the subjects would be HIGHLY RECOMMENDED!!!? You are dealing with legally stipulated limits by the FCC and the EU (and other countries and markets).? Also you need to become up-close-and-personal with the regulations, testing methods, and the various world-wide regulatory agencies. ?

Please walk before you attempt to run.? I've done EMC/RFI professionally for at least 40-years.? The discipline is not trivial.? Again, crawl, then walk, and finally run.

Dave - W?LEV?

On Mon, Feb 3, 2025 at 1:01?PM Rainer Hantsch via <office=[email protected]> wrote:

Hello, Bob.

Thanks for your explaining. I know that this is a complicated thing, but I bought? "tinySA Ultra"? to be able to find out if my developments are in safe distance to allowed limits of electromagnetic noise, or if (and where) my DUT excesses this limits.?
This saves a lot visits for pre-compliance testing and therefore lots of money (-> the reason why I bought the ULTRA for).

As far as I know, it is legal to do a self-declaration that a device is complying, but then it - of course - indeed has to be compliant. But knowing that my DUT is far below allowed limits before even doing a first pre-compliance test is always a good start.

So I would do the testing by either moving to a location some kilometers away from buildings and mobile phone antennas, etc., move to a deep parking house, or similar, ? and do two scans:
One without my DUT turned on (recording the environmental noise), and another one with my DUT turned on (recording environmental noise + DUT's noise). Or I build a Faraday cage using a fine and grounded metal mesh and do the above inside the laboratory. (will also reduce external influence) before.

The difference should be my DUT then, right?? As my developments usually are small devices for automating or recording something, they are often battery operated. If not, a certified power adapter with cable length shorter than 1m makes life also lots easier.

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This will at least give me information on noise generated by the DUT.?? Doing this math without an automated script is a horrible job, because tinySA (Ultra) by itself is not really easy to use (at least for me).

If additional tests are required (i.e. the Conduction Emitted Tests), this is another part I will have to do separately. But most important is the direct emission to air, because I often use plastic enclosures and digital electronics. Well, I already try to always use Microchip PIC controllers with internal oscillators, this drastically reduces radiation, but it is still digital, with lots of square waves therefore.

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Dave - W?LEV

Virus-free.