Thank you to a few readers for suggesting a post about the "tinySA". The tinySA is a low cost standalone spectrum analyzer which was made recently available from Chinese manufacturer "Hugen" who was the manufacturer that popularized the original NanoVNA. It can be found on Aliexpress for about $49 shipped worldwide. R&L also have US based stock available. The official specs from tinysa.org/wiki read:
- Spectrum Analyzer with two inputs, high quality MF/HF/VHF input for 0.1MHZ-350MHz, lesser quality UHF input for 240MHz-960MHz.
- 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.
- When not used as Spectrum Analyzer it can be used as Signal Generator, MF/HF/VHF sinus output between 0.1MHZ-350MHz, UHF square wave output between 240MHz-960MHz.
- 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
- Rechargeable battery allowing a minimum of at least 2 hours portable use
A spectrum analyzer allows you to view a defined slice of the frequency spectrum on a graph. It does not allow for demodulation of signals. We note that SDRs like the RTL-SDR could be used as a spectrum analyzer too with software like QSpectrumAnalzyer and Spektrum, however the advantage of the tinySA is that it is a standalone package with it's own screen that can easily be used in the field. Unlike an SDR extra computing devices like a computer or smartphone are not required.
Over on YouTube IMSAI Guy has been uploading a few videos reviewing the tinySA. From his videos he found a few issues including a slow update rate, harmonics and high phase noise. However, later he finds that most of the harmonic issues disappear as long as the input signal level is kept below -30dBm. In some more recent videos he also finds a fault with the attenuator chip on one of his tinySA units and repairs it by replacing the chip.