Kinda Neat

See it demonstrated here:

Vector Network Analyser? Hewlett Packard seem to have been selling them since about 1985.

As a mere hobbyist, Cursitor Doom wouldn't have known about them back then - they weren't cheap.

Neat, except for the dreadful UFL connectors.

I was simulating a very complex system, which we need to be stable over a wild range of loads. Instead of (slowly) simulating with a wild range of loads, I connected a 1 amp AC current source across the output and swept that, which makes an S22 VNA. I figure it's a good sign if the output impedance stays real and behaves itself.

LT Spice is great.

To be fair, they do apologise for these in the video. What is it you use and what are they good for frequency-wise?

Eh? Is there a new version out? I don't recognise that UI.

I like SMBs, which are easy to mate and un-mate. Good at maybe 5 GHz.

SMAs of course for faster stuff. There are some nice gold-plated edge launchers for under $2, OK to at least 10 GHz on FR4.

I've recently sampled some super high frequency edge launch SMAs, $6 sort of range.

That old PCB layout isn't right for that connector of course.

The big advantages of the UFLs is that they are small, cheap, and can be pick-and-place assembled like other parts. They suck to actually use. Good for one-time mating on production stuff, horrible to mate/unmate more often.

That's the current/normal version, just updated. I just expanded the plot plane for a screen cap. Does something look new?

But they're selling these for $385 a piece. And what do they consist of? Next to nothing! There's a small board with some silk-screen printing on it (or whatever they use nowadays) plus a dozen or so RF connectors and a handful of SMD resistors, caps and coils. Total component cost? Ten bucks? For $385 retail? Can't go wrong.

Electronics is often selling intellectual property. Things can and do sell for 10x or 20x cost. Microsoft has a pretty good margin on CDs and downloads. Tek sells $4 cables for $60.

If that VNA demo is any good, it took a bunch of EM simulation or PCB iterating. I bet it needs a lot of telephone support too. You could make your own.

No-name volume consumer stuff can have a 5% margin. Contract manufactuers make numbers like that.

They still are not. Even the cheapest one from his website costs ~2900EUR and this is a noname-you-never-know-what-it-is-actually-measuring device. The Tex and HP *measuring* units are expensive even if used. Way beyond the hobby-level pain threshold.

Best regards, Piotr

There are some cheap USB VNAs around. Just a little box with a few connectors, and some PC software. Amazon has them starting around $40

Most are 50 KHz to 900 MHz. Is that the ADI chip?

niptechnology.com:

then - they weren't cheap.

I think the one with the 30MHz lower limit is an AD chip, the 50kHz one use a Siliconlabs clock generator

Not to mention extremely difficult to make for yourself at home. The level of precision required at the higher frequencies will defeat all but the very best amateur constructors. A few thousandths of an inch out and it has to go in the bin. Highly precise parts; high precision placement. That's why they don't come cheap.

You'd have to pay me 40 bucks to take one of those pieces of junk away - and then it would go straight in the trash. It's strictly boat anchors from top manufacturers for me. Just a personal prejudice and certainly not the right approach for everyone, I freely admit. :)

Recent IC synthesizer technology is astounding. A few dollars worth of chip is better than a $20K signal generator used to be.

Software can fix things that used to require electronic precision.

• Use GR connectors.

APC7s.

Oh really? What about phase noise?

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We use LMX2571. Jitter is below what we can measure, indicated 1 ps RMS. Further-out phase noise is as good as the crystal oscillator reference. This is way better than any DDS.

The real money will be spent on the XO. A very good OCXO can be had nowadays for around $70.

Of course this synth needs software. The math is non-trivial, and TI won't help.

NanoVNA:

Note that it's really only 50K-300MHz; up to 900MHz uses harmonic trickery.

the screen is too small to read for me, even hard with glasses, but you can attach a phone using USN OTG or attach a computer - it's not so tiny then.

Clifford Heath.