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Why are spectrum analyzers so expensive?
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codingwithethanol:
@bd139 I have a budget tek right now but i was thinking about getting a little rigol down the line so thats good to know
@blueskull appreciate the input but those are still wallet biters
@T3sl4co1l yeah ive seen those but theyre mostly useful for hams, im trying to measure frequency response of filters and other circuits
codingwithethanol:
@exe that looks interesting but im wary of all PC based equip due to trash software support
@Psi does that have any affiliation with the GS youtube channel? Interesting coincidence if not
Bicurico:
Spectrum Analyzers are expensive for several reasons:

1) There is not a big market for them, so all engineering, research and development costs are split up between a fairly small amount of customers. This has changed recently with companies like Rigol and Siglent, mass-producing them, which lead to incredible affordable prices.

2) Spectrum Analyzers use expensive components. The core component of older swept spectrum analyzers (SSA) is the YIG, which is contains small Yttrium spheres for frequency down-mixing. If you search this forum, you will find posts from people trying to repair them and it is amazing technology - almost black magic! I still wonder how this can possible work at all. Then, modern spectrum analyzers offer FFT modes (Fast Fourrier Transformation). Instead of sweeping the frequency range, they digitize millions of samples and convert these time-domain samples into frequency domain. This requires a lot of processing power! It also allows a super smooth spectrum and waterfall display. Look at the 6-figure price tag Rohde&Schwarz spectrum analyzers and you get an idea...

3) High Frequency stops being "reasonable" at around 1GHz. Once you get above that value and especially above 2GHz, things start to behave oddly and you really need to take care of every detail: connectors, cables, everything needs to be "special" to not interfer with the signal you are analyzing. This becomes extremely expensive!

Regarding your choices:

50-200 Euro: You can purchase chinese clones of the NWT series. These work surprisingly well and I developed an alternative software for these devices. Take a look at my blog about this: https://vma-satellite.blogspot.com/

500-2000 Euro: You can consider second hand spectrum analyzers. These were normally very expensive machines, which are now sold at ridiculously low prices. But beware that you get no support, calibration and often no spare parts. What I have done is buy several broken units and then repair them, using some for spare parts. This way I ended up with 2x R&S CRTU, 2x R&S CMU200 and 1x HP 8594E. All in working order. But I have another 2x HP8594E (broken PSU) and 1x R&S CRTU (missing some boards) and spare parts. This takes space, time and money to get them in working order. And you still have no valid calibration, if that is important for you.

1500 Euro: Get yourself the best performance/price ration currently on the market and buy a Siglent SSA3021X. New, calibrated with warranty. And it can be hacked for increased bandwith (3.2GHz) and all options.

Regards,
Vitor
Bicurico:
Forgot to add some thoughts on SDR:

Yes, you can buy a HackRF One and run this amazing software: https://github.com/pavsa/hackrf-spectrum-analyzer. But you will soon find out that functionality/measurements are limited and that the software/device crashes a lot.

Then you have the ADALM Pluto: I cannot recommend this as a spectrum analyzer replacement, at all.

SDR: Yes, with SDR# (sdrsharp) you can do spectrum analysis and even demodulate most analog and some digital signals! BUT: In my opinion this is in no way a replacement for a real spectrum analyzer. These devices do not support a swept spectrum analysis, so that your frequency range is limited (4MHz to 40MHz, depending on the signal). If you want to look i.e. at the CATV band from 50-850MHz, you won't be able to do that, unless you buy the SDR# specific AirSpy, which costs a lot more than a regular RTL2832 dongle.

Plus, most tools are Linux only and you can literally spend hours to get a particular driver/software up and running. GNU Radio is great and you can learn so much using it - especially if you are interested in HF engineering and have a Python/C++ programming background. Sounds complicated? It is!

In my honest and modest opinion, if all you want is a spectrum analyzer, then either go cheap with SMA/NWT devices or buy a SSA3021X or spend some time reading about which are the best second hand devices to buy. I think there was a whole thread here about second hand spectrum analyzers.

Good models are HP/Agilent 859x series (beware of the PSUs - they are a nightmare to repair: I have 3 broken ones and repair seems impossible) and Rohde&Schwarz CMU200/CRTU - these are actually Protocol/Communication Tester, but offer a fully working spectrum analyzer, too.

Regards,
Vitor
codingwithethanol:
Why is Yttrium required???? I had a hunch these things ran on fairy dust but HUH?
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