Special Project: Receive a Spectrum Analyzer and Demonstrate EMI debugging, low power design, or IoT Application

It's reasonable, but slightly poorer performance than the datasheet typical values.

Ignoring the 'gain flatness' since that seems like a typo in the datasheet (it's an obsolete part, MSA-1105, there doesn't seem to be a more recent datasheet).

At 500 MHz the typical gain should be 12.0 dB, but as can be seen by the marker M3,  I get 11.0 dB, so a 1 dB difference there.

At 1 GHz, the measured gain should be 10.5 dB, but I get 9.4 dB (1.1 dB difference).

In summary, it seems fine for the range of this part (1 GHz). The display below is up to 3 GHz just out of curiosity how the part and layout behaves there.

Hello Jan,

Thanks for the suggestion - but I sent it back.

They didn't offer me an exchange for a good one.

MK

Is the colour code brown brown black silver? 11 µH 10%?

I have a few at home that I can miss

6.8µ, 10µ, 27µ, 56, 100µ

Here are a couple of pics of the TEM cell.

It starts off at 50MHz or so with SWR = 1.4 and it rises to 3 at about 650MHz - which I expect will be the upper limit of it's usefullness.

That's a 45cm ruler !

I doubt if I'll get a chance to play with it much more for a couple of weeks. I'll do a blog once I get some reults.

My amplifier is  a bit hard to get into so apart from tightening the nuts holding the connectors on I haven't poked at it too much yet. I haven't got a good look at the PCB but I think it's very like this one.

I bought one of those but it turned up with one of the resistor shaped inductors broken in half

The new one is in a little extruded box.

I have a power attenuator on the way - I don't feel happy about exposing the R&S to a £20 RF power amp.

MK

Exactly, I'm thinking on building some stuff that I could use with my SDR.
Interesting how you reutilized a board to build that amp, did it work?

Ooooh. The FPC1500 has been on my "dream test equipment list" ever since it was road tested here on E14. This seems like a nice variation on the usual road test theme too.

I've been crazy busy lately but that should soon be coming to an end. I may have to put in an application, but will probably limit myself to antenna matching so I don't promise more than I know I can deliver.

Wow - this is another exciting opportunity, especially if it comes with some support for the other tidbits necessary. The cost of accessories can be staggering in the RF space as noted by others - but the cost is perhaps not entirely unjustified as there may be cheap adapters from unknown sources which could be problematic at higher frequencies, have strange signal losses or reflections or be so mechanically out of spec that they damage your good connectors. I've had some firsthand experience of this, luckily not losing anything too expensive in the process.

Because of the expense and the length of the possible wishlists for such applications which may or may not be within the realm of possibility, perhaps there could be a middle ground where some of the requested items are licensed on a trial basis or lent for the period of the RoadTest (and any potential damages covered as well). I've seen the prices for some near field probes and LISNs and I've often felt that DIY would be best, but it probably won't allow for demonstrating the best ability of the equipment.

I'm not sure if I will have the time to devote to this, so I have selected "somewhat interested" - perhaps the BLE aspect may be the easier one to tackle, but it would seem that in most application cases, it would be best to have someone that is actively in the middle of designing or re-designing something (e.g. an SMPS conversion from Si to GaN, an IoT device readying for market, testing various printed antenna or stripline designs). That is usually a pretty involved and long-term project with potentially big investment (especially if things aren't all good at first). The number of engineers who are experienced enough to be at that stage of the product lifecycle would be relatively limited in number - I'm even doubting my own qualifications for this one.

- Gough

You're welcome.

Yes, this is a very fine company. I know the bosses in Vienna, so far as I can remember; it was a long time ago. In the 1990s I worked with them at a trade fair exhibition.

At that time I also was in training in measuring devices, such as radio measuring stations.

I worked with these smaller devices in the 1980s.

I spoke about this DC-LISN in the seminar here in Austria and asked whether they offered such a possibility.

And indeed, this do-it-yourself version is offered. The Würth company supplies the most important parts - the inductions and more.

It is a LISN similar to the TEKbox type. Tekbox Digital Solutions | Tekbox TBOH01 5uH LISN Line Impedance Stabilisation Network - CISPR 25

More precisely - the point is in the details: The output to the measuring device.

I couldn't really find that on the web. With this circuit everything is described in detail and is a reference to the larger LISN.

You can build a 5µH type using this option, or a 50µH type from the www ....

There are some circuit diagrams there.

This LISN HM6050 (now version -2) comes from the Hameg times, before R&S bought the Hameg company and thus also took over their measuring devices.

And in there, the coils are many times larger and heavier.

The wire is also specially spooled accordingly, i.e. not as a simple wire spool.

Yes, the technology ..... something new is constantly being discovered and worked out.

Hi Gerald,

Thanks for sharing this, it is really great! Nice of R&S to publish all the details, even a DC version is hard to buy (affordably) and gives the option for anyone to build at reasonable cost. I'd like to assemble this too at some point.

Hi shabaz

They are not so large. You can it put on a table.

Tekbox Digital Solutions | Tekbox Open TEM Cells for EMC Pre-Compliance Testing

AN Immunity Testing with Tekbox TEM cells (batronix.com)

Measurement - TEM-Cells (Stripline) (batronix.com)

Yes, there are bigger one.

EMCoS

I'm also interesting about the TEM-cells. At the time I made roadtest with the FPC1500 I looked for such cells.