TinySA – small spectrum analyzer and signal generator
tinysa.org
tinysa.org
https://www.linkedin.com/posts/eyesonukraine_drone-detector-...
The firmware source is on GitHub at https://github.com/erikkaashoek/tinySA.
Fun fact, the famous actress Hedy Lamarr actually was instrumental in inventing it!
In those cases it's not used to make detection harder though but to be more resilient against interference.
With frequency hopping only one frequency is used at once, and they're selected according to a sequence that matches a shared PRNG. As I understand it, that's what Bluetooth and some Wifi links do. They switch between discrete bands very fast.
Spread spectrum is a little different. During modulation, as with FM a series of side bands spread out. Normally we would limit these as they're considered "interference". But with the right modulator you can spread (and indeed encrypt at the RF link level) information into some bands but not others. Although all sidebands are present, to an observer who can't tell which ones carry the data at any moment, it makes no sense to even try demodulating the signal.
Neither solutions are much use if you need to communicate back because triangulation alone is enough to find you.
Curious if this tallys with your understanding, its over a decade since I had anything to so with this sort of thing. The best summary I recall was in Ross Anderson's "Security Engineering" book (first ed.)
If I understand the capabilities of modern Software Defined Radio systems, then they can monitor many different frequencies at the same time which might defeat those old systems. It’s been a long time since I read up on the current ideas and capabilities.
Haven't been keeping up with it as much as I should, but that's very interesting.
Spread spectrum refers to any technique where a narrowband signal is deliberately spread to occupy a larger bandwidth.
Frequency-hopping is an example of a spread spectrum technique; they're not different things. Direct-sequence spread spectrum (which is what I think you're describing) is also a spread spectrum technique.
There are also other techniques; the most popular one is probably the chirp spread spectrum as used in LoRA.
These are very cool and fun, but I found myself using my NanoVNA a lot more than my TinySA
I guess what I'm asking: What features of the NanoVNA make it the "way to go"?
FOR ME: It's the PC SW that allows a big-screen, which converts the fundamental "R+jX" measurement into many different views. https://nanovna.com/?page_id=90 Awesome.
I found, for what I do, having a vector network analyzer was more useful that having a spectrum analyzer. Specifically, measuring the SWR of antennas and measuring the resonance frequency of filters.
Another cool tip is to use NanoVNASaver (https://nanovna.com/?page_id=90)
Picoscopes are great and very affordable on a work budget, but a bit much for my home budget particularly if you want a mixed signal one.
I have one of those (AD2; there is a newer AD3 available), and it's quite a lot of 'stuff' in one package. I wish I had one when I was learning EE. But these days, I use them as 'data acquisition and control' modules to generate and capture signals under program (Python) control. I think of them sort of as a fancy Arduino -- although it can do many more analog tricks. Recommended.
Many people like the newer Chinese scopes; see https://youtu.be/S8jrpCoZyx8?si=oaI_gxOylYhOSp-m but I have only limited experience with those. Their UI seems less obvious than Tek scopes.
The other very important specs besides what you've mentioned are # of channels, and highest operating frequency. Others today would be how fast is the ADC, how many bits, storage depth, post-capture analysis capabilities, and so much more.
But if you want to remote control the scope, stay away from the Chinese ones: that part of the FW is often very buggy.
I don't think you are going to find much for less than a Picoscope.
Maybe something like the Analog Discovery 3? Under 400 USD, 2 channel oscilloscope (30 MHz), 16 channel digital, 2 channel arbitrary waveform generator (12 Mhz) https://digilent.com/shop/analog-discovery-3/
Rigol and Siglent both make mixed signal scopes that will do two channels analog at 100MHz and 16 channel digital for ~1k USD.
30 Mhz is a bit low, but would cover the lower speed digital stuff which is what I need a scope for most of the time.
Two scope channels, some logic analyser channels, ideally 50 MHz, ideally 12 bit. That works at as about £500 from Picoscope which is pretty cheap. I was astonished at these Spectrum Analyzers and I was wondering if there was something from china at a fraction of that.
This is a great explanation of the signal path: https://www.youtube.com/watch?v=z63cXhYzS1A
https://www.keysight.com/us/en/support/EDUX1052A/oscilloscop...
They also have DSOX1202A & DSOX1202G for ~$1k -> ~$1.2k
Are they any good? In the market for a very cheap 'scope - think, looking at i2c signals, 0v-5v analog signals from (for example) a temp sensor, etc.
Is the buspirate still around?
Gone are the days when you had to beg a club member with a $10,000 MSRPed bench VNA in the back of his truck to swing by. You can pull a VNA out of a bag while still up the tower.
High-Q antennas designs that are sensitive to construction and mounting are much more realistic to use when you can VNA them in situ.
My question is if someone is actually using advanced satellite surveillance capabilities to augment their running joke by looking in my window, (which can’t be ruled out in my world unfortunately), would one of these devices pick up the RF?
I was supposed to have gone crazy blah blah blah while they tell me what is on my counter in a mobile game.
Sadly, we decided they also are just leveraging the housekeeper and making some good guesses in a few cases. Yet there is one window they kept coming up with what was in front of it. No visible cams in line of sight.
I didn't know of this one, I'll check it out. It looks way better and the basic one is a lot cheaper too!
Still would have looked nuts with the TinySA, but... less so.
But the signal was intermittent, and I talked to all the neighbors in all three units, and none had anything that sounded like it could be the culprit. It eventually just stopped happening, so I never tracked it down.
I was able to stop the rogue attacks with Cisco Meraki. This was extremely beneficial.
Since I moved, I have had to change channels a few times due to interference. The dashboards in the Meraki, are great at visualizing and identifying sources.
I also made it a point to look ridiculous and walk around to meet the neighbors to understand what is not “rogue” and tell them I was having problems. This was to build an inventory and ensure I didn't accidentally jam something thinking it was a rogue attack. I let them know to inform me if they experienced problems.
Clearly someone was sending waves of wireless hackers my way as a poorly defined joke. Despite efforts to get inventory of my surroundings, there are still a ton of unknown devices in the area I cannot identify with precision, and the area is not highly populated. No one knows how many access points and devices they are running any more for smart lights, cams etc.
Finding the source as far as I can tell may be more feasible here w GPS receiver - yet I have not had a need.
I probably don't have a use for this type of thing, any more, but, at one time, I would have snatched one up, immediately.
I used to use the HP 3310A but they are analog and really old now
[1]: https://www.siglenteu.com/waveform-generators/sdg1000x-serie...
That one for 350 euros looks good
edit: https://tinysa.org/wiki/pmwiki.php?n=Main.Specification here says it works from 100kHz for the low output. When I just tried it did let me select 60kHz and turn it into output mode. Haven't hooked it up to a scope to see what it does. Sorry no time to set it all up now. 60kHz is very low though, if you browse AliExpress then I'm sure plenty of signal generators will offer that for a really low price (cheaper than the tinySA)
edit 2: Sorry my European brain kicked in and missed you are looking for a 60Hz one that is very precise and not a 60kHz one. I'd better get some sleep.