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Comment by teleforce | Hacker News Reader

Fun facts, you can build your own VNA from scratch using open source GNU Radio toolkit with any off-the-shelf SDR platform for example using the low-cost ADALM-Pluto or you can go fully gung ho with the more capable RFSoC platform [1],[2],[3],[4]:

[1] Lab notebook of experiments in GNURadio:

http://www.swigerco.com/gnuradio/

[2] Off-the-Shelf Reconfigurable Software Define Radio Approach for Vector Network Analyzer:

https://jati.apu.edu.my/files/2018/12/2018_Issue2_Paper1.pdf

[3] ADALM-PLUTO: Software-Defined Radio Active Learning Module (USD230):

https://www.analog.com/en/resources/evaluation-hardware-and-...

[4] RFSoC 4x2 Development Kit Overview (USD2K):

https://news.ycombinator.com/item?id=39427825

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VNAs are fundamentally narrow-band instruments. This:

> The RFsoC 4x2 board has 4x RF ADCs (5 GSPS) and 2x RF DACs (9.85 GSPS)

is like chasing after a fly with a sledgehammer. It wildly over-specs something that is almost completely useless for the task at hand (real time bandwidth, mass of hammer) while it wildly under-specs the important parts (frequency range, directivity, agility of hammer).

If you have the RFSoC the VNA is the low hanging fruit.

If you're doing modern wireless systems measurement and testing (4G/5G) most likely you will need spectrum analyzer (SA), vector signal analyzer (VSA) and vector signal generator (VSG).

The cost of all the disparate systems namely VNA + SA + VSA + VSG will easily cost north of USD100K for the used ones and multiple times more for the new ones. With the low cost RFSoC platform together with the standard RF test kit (attenuater, pre-amp, multiplexer, switch, etc) you are pretty good to go.

It's really perplexing that no one including the Chinese are trying to disrupt this industry, Keysight and R&S are currently charging arms and legs for their equipments even the basic one like VNA.

> It's really perplexing that no one including the Chinese are trying to disrupt this industry

No point.

1) Low volumes

These things never really go obsolete and the replacement rates are abysmal.

2) Race to the bottom

Once you disrupt it, everybody sees that you disrupted it, and everybody clones you and piles in.

Customer support is the only differentiator. To fund that, you have to charge north of $10K per unit--generally north of $25K.

Tektronix found this out the hard way with their real time spectrum analyzers. It was a nice disruption at the $5K point. Lots of people bought them. Then demand dropped like a rock because everybody who needed one bought one. And because the revenue crashed Tektronix laid off the development group--who are also the same people you need for advanced customer support.

siglent is moving in on VNAs a bit but i absolutely agree. as a ham i could do with all of above :-)

>low-cost ADALM-Pluto

~$250, meanwhile Chinese nanoVNA clones are ~$25-40, add prescaler and you can reach 6GHz.

Anecdotally I have seen nanoVNAs being used with directional antennas in Ukraine as crude drone finders. https://www.reddit.com/r/CombatFootage/comments/1afspa8/comb...

Very late reply but that is most likely a tinySA, a compact and inexpensive spectrum analyzer that uses the same case as many nanoVNAs: https://www.tinysa.org/

Wow, that RFSoC board is incredibly cheap - ours cost $12K or so, and we needed special approval too under defence regulations.

> or you can go fully gung ho with the more capable RFSoC platform

You can't:

> The RFSOC 4x2 is currently only available to staff at accredited Universities and Research Institutes.

If you go to the Real Digital site (vendor that makes the board), they appear to also sell it commercially, albeit at the higher price of ~$4k (compared to their academic pricing of ~$2k).

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