[HN Gopher] TinySA - small spectrum analyzer and signal generator
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TinySA - small spectrum analyzer and signal generator
Author : transpute
Score : 134 points
Date : 2024-01-26 13:51 UTC (9 hours ago)
(HTM) web link (www.tinysa.org)
(TXT) w3m dump (www.tinysa.org)
| cadr wrote:
| Make sure to heed the maximum input and use an attenuator!
|
| These are very cool and fun, but I found myself using my NanoVNA
| a lot more than my TinySA
|
| https://nanovna.com/
| willis936 wrote:
| Both are super handy and super cheap (relative to conventional
| SAs and NAs). Handy for the personal shop of any EE.
| cadr wrote:
| For sure - if you can afford them, get both. I was just
| surprised because I expected to use the SA a lot more when I
| got it. But I am mostly either testing filters are designing
| antennas, and the NA is the way to go.
| GeorgeTirebiter wrote:
| I have only NanoVNAs, up to the 6 GHz one (
| https://nanorfe.com/vna6000.html ). But the TinySA at the
| frequencies of interest seems about the same?
|
| 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.
| codefoster wrote:
| I use a nanoVNA for analyzing antennas. Cool tip is you can
| tether it to an Android device and get a bigger, nicer touch
| screen.
| cadr wrote:
| That's cool - didn't know that about Android.
|
| Another cool tip is to use NanoVNASaver
| (https://nanovna.com/?page_id=90)
| 127361 wrote:
| These are being used by the Ukrainian army for detecting incoming
| russian drones.
|
| https://www.linkedin.com/posts/eyesonukraine_drone-detector-...
|
| The firmware source is on GitHub at
| https://github.com/erikkaashoek/tinySA.
| TheLoafOfBread wrote:
| If they know frequency of drones (i.e. Lancet in this case) can
| they create something like a HARM drone, which will guide
| itself on source of the signal to intercept the drone itself?
| ramses0 wrote:
| A drone dangling balls of yarn...
| cadr wrote:
| It surprises me that military drones aren't using spread
| spectrum to make this harder.
| nurettin wrote:
| Is that a real thing, or a star trek reference?
| cadr wrote:
| A real thing: https://en.wikipedia.org/wiki/Spread_spectrum
|
| Fun fact, the famous actress Hedy Lamarr actually was
| instrumental in inventing it!
| avisser wrote:
| You can tell GP is under 40 or they'd probably remember
| cordless phones "Now with 900mhz spread-spectrum
| technology"
| cshimmin wrote:
| Definitely a real thing. Also, during WWII actress Hedy
| Lamarr developed a system for spread spectrum torpedo
| guidance to prevent jamming, but the general idea predates
| that.
| p_j_w wrote:
| Spread Spectrum is very real, it was used in 802.11b.
| stoneman24 wrote:
| Yes, it's a thing. A long time ago, my work involved a
| frequency hopping, spread spectrum radio link. Can't say
| much about it but I'm sure that the technology has improved
| since then.
| NotSammyHagar wrote:
| Isn't good old cdma a spreadspectrum technique, used for
| cell phones back in the day from quallcomm?
| MegaDeKay wrote:
| Yes, one of the four basic types. CDMA is the Direct
| Sequence Spread Spectrum variant.
|
| https://en.wikipedia.org/wiki/Spread_spectrum
| nonrandomstring wrote:
| Hopefully its not pedantic or unwelcome of me to make the
| distinction between spread-spectrum and frequency
| hopping.
|
| 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.)
| stoneman24 wrote:
| No, it's fine by me. I believe that it was thought that
| the combination of frequency hopping and spread spectrum
| would make it difficult to monitor and jam ( other than
| very wide band jamming). My application was rapidly
| moving so triangulation would be difficult.
|
| 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.
| nonrandomstring wrote:
| > If I understand the capabilities of modern Software
| Defined Radio systems, then they can monitor many
| different frequencies at the same time
|
| Haven't been keeping up with it as much as I should, but
| that's very interesting.
| NovemberWhiskey wrote:
| > _Hopefully its not pedantic or unwelcome of me to make
| the distinction between spread-spectrum and frequency
| hopping_
|
| 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.
| nonrandomstring wrote:
| Thanks for the clarification NW
| squarefoot wrote:
| Are they using any peculiar feature of the TinySA? From the
| photo it seems they're doing normal spectrum monitoring, but
| for that purpose a SDR dongle would work as well, For rexample
| the one by rtl-sdr.com. Beside being much cheaper, it can be
| interfaced easily with also cheap *Pi-like single board
| computers and operated remotely to cover wide areas. But again
| I have no idea if the TinySA offers any advantage over a SDR
| receiver in that context.
| helpfulContrib wrote:
| Portability and effectiveness. Sure, for you a dongle is
| great. But not if you're in the trenches covered in mud and
| you have to dig it out of a pocket somewhere ..
| ThrowawayTestr wrote:
| The other reply to you is buried for some reason but as they
| said, a hand-held battery powered unit is more convenient
| than something that requires a computer.
| okl wrote:
| Unfortunately, the bandwidth on the RTL-based dongles is
| quite limited. This means that you'll only see some kHz of
| spectrum around your LO frequency.
| ChrisMarshallNY wrote:
| This looks exceedingly cool.
|
| 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.
| PM_me_your_math wrote:
| The TinySA is excellent for finding sources of RFI, although you
| want to use a small yagi or loop antenna.
| cadr wrote:
| I wish I had it when I was having an RFI issue in my
| neighborhood. I ended up with my RTL-SDR hooked up to my mac
| with a homemade copper-on-tape-on-cardboard yagi, and I looked
| like I was a tinfoil hat away from being needing to be put
| away.
|
| Still would have looked nuts with the TinySA, but... less so.
| applied_heat wrote:
| Anyone know a signal generator that can do 60.000 Hz?
|
| I used to use the HP 3310A but they are analog and really old now
| magicalhippo wrote:
| Any decent digital one should be able to do that I imagine.
| I've got an entry-level Siglent[1], it can do 1 microHz and up.
| Or am I missing something?
|
| [1]: https://www.siglenteu.com/waveform-
| generators/sdg1000x-serie...
| applied_heat wrote:
| Thanks. A lot of the hobbyist level ones did not do low
| frequencies at all or precisely enough to compare to
| electrical grid frequency
|
| That one for 350 euros looks good
| ijhuygft776 wrote:
| wow, cheap.
| rkangel wrote:
| Similarly can anyone recommend an affordable oscilloscope?
| Ideally mixed signal and PC attached.
|
| 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.
| gte525u wrote:
| Analog discovery series is cheap and good enough for a lot of
| tasks.
| GeorgeTirebiter wrote:
| I've found Analog Discovery true to its name -- great for
| exploring analog. The scope portion is limited in channel
| sensitivity and frequency. It's also a bit of a kludge, in
| that the probes attach via a 2x20 (?) front-panel 0.1" center
| connector to an adaptor board that has BNC females for the
| scope probes.
|
| 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.
| GeorgeTirebiter wrote:
| Get a used TDS-2xxx series used on ebay. I prefer Tek scopes,
| great trigger, and the TDS 210, TDS220 and their ilk continue
| to work very well. As to PC attach, yes, you can do that, but
| that will need some s/w.
|
| 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.
| cadr wrote:
| What frequencies, how many channels of analog/digital, what bit
| depth, how much memory, etc? What is your actual application?
| And what do you mean "PC attached" here? What is your budget?
|
| 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.
| rkangel wrote:
| I wasn't familiar with the the Analog Discovery. Seems good
| value as it covers a lot of bases in one go.
|
| 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 PS500 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.
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