TinySA a cheap spectrum analyzer

 

When you are working with RF, you might want to see the spectrum of you signals, and for that I worked with various spectrum analyzers from hamradio friends, the club spectrum analyzer (a Rigol DSA815-TG) and even on the job. Because of that I had my eye on a Rigol DSA815-TG  for a few years now. 

Due to a change of interested and using my NanoVNA's quite a lot, my eye wandered off to the Siglent SVA1015X (which includes also has a VNA option). With a street prices of € 1180 for the Rigol DSA815-TG and € 1640 for the Siglent SVA1015X, both models are considered "avoidable" with the range of amateur usage. And yes I would like to have one of those in my Shack (preferable the Siglent), but until there is enough hobby budget in the PH2LB hobby fund (or there will be declarable work to do), I will keep on dreaming of having a "real" Spectrum analyzer in my shack. 

But then things changed

In 2020 things changed: the TinySA was launched. 

The tinySA is a small spectrum analyzer or signal generator, primarily intended for 0.1MHz to 350MHz input/output but it has some nice other capabilities:

  • Spectrum Analyzer with two inputs, high quality MF/HF/VHF input for 0.1MHZ-350MHz, lesser quality UHF input for 240MHz-960MHz  
  • Signal Generator with two output, sinus output for 0.1MHz - 350MHz and square wave output for 240MHz-960MHz when not used as Spectrum Analyzer.
  • Switchable resolution bandpass filters for both ranges between 2.6kHz and 640kHz
  • Color display showing 290 scan points covering up to the full low or high frequency range.
  • Input Step attenuator from 0dB to 31dB for the MF/HF/VHF input.
  • A built-in calibration signal generator that is used for automatic self test and low input calibration.
  • Connected to a PC via USB it becomes a PC controlled Spectrum Analyzer or Signal Generator
  • Rechargeable battery allowing a minimum of at least 2 hours portable use
  • Max input level +10dBm (10mW)

Due to the low cost and very small form factor there are certain relevant limitations and I still want one of the spectrum analyzers mentioned above, but I bought a  TinySA for a few months ago anyway.

And it comes in a nice box . . . 

tinysa_002

. . . which you can use to keep everything together. 

tinysa_001

Package content : 

  • 1 x TinySA with 2.8" display
  • 2 x SMA cables
  • 1 x SMA F/F adapter
  • 1 x Telescope antenne with SMA connector
  • 1 x strap
  • 1 x guitar plectrum to use as a stylus

 

Update 11 juli 2022 : I build a 40dB RF sampler to be used with my TinySA and my OZ2CPU digitale RF mW-dBm-mV meter.

 

TinySA Ultra the new TInySA

In the winter of 2022 I bought the original TinySA at Eleshop and there already where  rumors that there would be one with a bigger screen.  But I bought it any way and loved it.

Early November 2022 there was announcement in the TinySA groups.io forum the the Ultra was about to be released (check out the video). The first stock on AliExpress was sold out very quickly but the also released a list of re-sellers and on that list was EleShop in the Netherlands. So when it was listed in the web shop,  I ordered it right away.

Why do you need a new TinySA?

You might ask why order a new TinySA when you already have one ? Well there are a few reasons.

  1. I used the original TinySA quite a bit, but just like the small NanoVNA I had problems with the size of the screen (a quick look without reading glasses is no longer an option for me). With the almost 4" screen size of the TinySA Ultra I can have a look without my reading glasses.
  2. It has a SD-card slot build in, just like my NanoVNA H4. This allows me to save screenshots of the measurement and publish them on this website.
  3. I probably won't use the Ultra bandwidth up to 6GHz much, but it's always nice to have it in there just in case (you never know)

It has arrived.

On 1 December 2022 the TInySA Ultra which I ordered at EleShop arrived at my door step.

tinysa_ultra_03

Nicely packed 

tinysa_ultra_02

And ofcourse you have to power it up.

tinysa_ultra_01

I played around with it and have to say I'm impressed. The designer Erik Kaashoek (PD0EK)  has put a few video's out on YouTube showing the variouse possibility of the TinySA and the TinySA Ultra. 

Specifications 

User interface: 

  • Display resolution 480*320 pixels
  • Screen diagonal 4"
  • 16 bits per RGB pixels
  • Resistive touch control
  • Jog switch control
  • USB serial port control
  • Optional TTL USART port on the internal PCB
  • Linear power supply to avoid switching noise.

Spectrum Analyzer spec:

  • Input frequency range from 100kHz to 800MHz in normal mode and up to 6GHz with ULTRA mode enabled
  • Input impedance 50 ohm when input attenuation set to 10dB or more.
  • Selectable manual and automatic input attenuation between 0dB and 31dB in 1 dB steps when LNA not active
  • Absolute maximum input level of +10dBm with 0dB internal attenuation
  • Absolute maximum short term peak input power of +20dBm with 30dB internal attenuation
  • Suggested maximum input power of +5dBm with internal attenuation in automatic mode
  • For best measurements keep input power below -25dBm
  • Input Intercept Point of third order modulation products (IIP3) of +15dBm with 0dB internal attenuation
  • 1dB compression point at -1dBm with 0dB internal attenuation
  • Power detector resolution of 0.5dB and linearity versus frequency of +/-2dB
  • Absolute power level accuracy after power level calibration of +/- 2dB
  • Built-in optional 20dB LNA with Noise Figure of 5dB
  • Lowest discernible signal without LNA at 30MHz using a resolution bandwidth of 30kHz of -102dBm
  • Lowest discernible signal with LNA at 30MHz using a resolution bandwidth of 200kHz of -145dBm
  • Frequency accuracy equal to the selected resolution bandwidth
  • Phase noise of -90dB/Hz at 100kHz offset and -120dB/Hz at 1MHz offset
  • Spur free dynamic range when using a 30kHz resolution bandwidth of 70dB
  • Resolution filters of 0.2, 1, 3, 10, 30, 100, 300, 600 and 850 kHz.
  • On screen resolution of 51, 101, 145, 290 or 450 measurement points.
  • Scanning speed of over 1000 points/second using largest resolution filters.
  • Automatic optimization of actual scanning points to ensure coverage of the whole scan range regardless of the chosen resolution bandwidth
  • Spur suppression option for assessing if certain signals are internally generated or actually present in the input signal
  • Headphone output for listening to the demodulated audio (AM only)

Signal Generator spec:

  • Sine wave output with harmonics below -40dB of fundamental from 100kHz to 800MHz
  • Output level selectable in 1dB steps between -110dBm and -20dBm
  • Above 800MHz choice of two output modes:
    • Cleanest signal mode: square wave, up to 4.4GHz with coarse frequency steps and less accurate output level
    • Highest accuracy mode: reduced harmonics with possibly strong spurs up to 5.4GHz with frequency resolution equal to below 800MHz and fine output level steps.
  • Level accuracy +/- 2dB up to 800Mhz between -72dBm and -18dBm, less accuracy below -72dBm
  • Output frequency resolution 44Hz below 800MHz
  • Optional AM or FM modulation frequencies between 50Hz and 5kHz (AM) or 1kHz(FM) or sweep over selectable frequency span
  • AM modulation depth between 10% and 100%
  • FM deviation between 1kHz and 300kHz
  • Optional output level sweep over maximum the entire output level range

Reference generator spec:

  • Optional square wave output with fundamental at -35.6dBm connected to cal output
  • Frequency can be set to 1MHz, 2MHz, 4MHz, 10MHz, 15MHz or 30MHz.

Battery spec:

  • Charging time max 1 hour on 500mA minimum USB port or USB charger
  • Operation on fully charged battery for at least 2 hours

Source : TinySA wiki

 

 

Conclusion

Do I like it? Yes absolutely. After I got it in I immediately tested it with a few standard things such as reference signal generator, playing with the RBW and of course seeing how fast it is. And as icing on the cake, I connected my -40dB RF sampler to view the signal from one of my QRP CW transmitters. The result was as expected.

Is it  missing features? I'm sure there are, but I haven't run into that with my experiments yet.

Is it accurate enough? I'm a radio amateur which is my hobby and not my profession, and i'm not building business critical system. So for me, it's accurate enough. For you ? I don't know take a look a the specs. 

Is it worth the money? As a radio amateur who often experiments up to 70 cm (sometimes at 13 cm) and also does something with LORA, the TInySA Ultra has a very good price-quality ratio and is a great addition to the shack or for hunting down QRM sources outdoor. So for me it's a yes.

Will it be supported ? Also for the TinySA Ultra, the designer Erik Kaashoek (PD0EK) will have regularly  new firmware releases with bug fixes and new features and he can also often be found on the TinySA groups.io forum to listen to findings and discuss new features.

Overall, I find it to be a very nice tool and well worth the investment. 

Tip : if you have a TinySA (Ultra) and you work with transmitters, build an RF sampler because the input is max +6dBm.  Also build or buy a set of various attenuators with a few different values for example 10, 20 and 30dB. 

   

All though I still have my eye on a Siglent SVA1015X (1.5GHz SA incl VNA), with the LiteVNA64 and the TinySA Ultra I have a nice set of measurement tools available in the shack (and in the field) to do some measurements on my experiments. Is it pro stuff? No, but for my amateur radio hobby it's good enough :-)