The tinySA is a compact, low-cost handheld spectrum analyzer and RF signal generator designed for hobbyists, radio amateurs, educators, and engineers. It comes in three different variants and can be used for RF debugging, signal inspection, interference hunting, filter testing, antenna-related measurements, and basic RF education, both in the field and on the bench.
The product line includes the tinySA Basic, tinySA Ultra, and tinySA Ultra+, which mainly differ in their supported frequency ranges and performance. The tinySA Basic supports 100 kHz to 350 MHz on its low input and up to about 960 MHz on the high input, while the Ultra and Ultra+ models can observe signals up to 12GHz. The devices run from an internal rechargeable battery with USB-C charging, support firmware updates, internal self-test and calibration routines, marker and peak detection, configurable frequency span and amplitude settings, and PC control over USB. Input protection limits are specified at +10 dBm RF power and up to 10 V DC, with external attenuators or DC blocks recommended for higher-level signals.
tinySA Specifications:
| Feature | tinySA Basic | tinySA Ultra (ZS405) | tinySA Ultra+ (ZS406) | tinySA Ultra+ (ZS407) |
|---|---|---|---|---|
| Main MCU | STM32F072 | STM32F303 |
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| Storage | PC via USB only | MicroSD Card Slot |
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| Display | 2.8" TFT Touch (320×240) | 4.0" TFT Touch (480×320) |
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| Frequency Range (Analyzer) | Low Input: 100kHz – 350MHz High Input: 240MHz – 960MHz | Normal: 100kHz – 800MHz Ultra: Up to 5.3GHz Harmonic mode ~10–12 GHz | Normal: 100kHz – 900MHz Ultra: Up to 5.4GHz Harmonic mode ~10–12 GHz | Normal: 100kHz – 900MHz Ultra: Up to 7.3GHz Harmonic mode ~10–12 GHz |
| RBW Filters | 2.6kHz – 640kHz | 200Hz – 850kHz |
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| Scan Points | Max 290 points | Max 450 points |
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| Signal Generator (Sine) | 100kHz – 350MHz | 100kHz – 800MHz | 100kHz – 900MHz |
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| Signal Generator (Square) | 240MHz – 960MHz | Up to 4.4GHz | Up to 6.3GHz | |
| Int Signal Generator | N/A | Up to 5.3GHz | Up to 5.4GHz | Up to 7.3GHz |
| Phase Noise (@30MHz, 100kHz offset) | -98 dBc/Hz | -108 dBc/Hz |
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| LNA (Low Noise Amp) | None | Built-in 20dB(Switchable) |
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| Attenuator | 0dB – 31dB (Manual/Auto) | 0dB – 31dB (Step Attenuator) |
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| Audio Output | None | 3.5mm Headphone Jack |
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| USB | USB-C (CDC Serial) |
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| Power | USB-C for power and charging ~2 Hours (Internal LiPo) | USB-C for power and charging ~2 Hours (3000mAh) | >3 Hours (5000mAh) USB-C for power and charging |
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| Dimensions | 54 x 85.5 x 11 mm | 117 x 72 x 23 mm |
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Note: Check out the official comparison table on the wiki for a more detailed comparison.
In terms of software support, tinySA runs fully open-source firmware, which is available on GitHub and maintained by the community, with active development for both tinySA Basic and tinySA Ultra/Ultra+ variants. The firmware can be compiled using standard GNU Arm Embedded toolchains or via Docker, with build instructions and targets for both tinySA Basic and Ultra variants included in the repository. You can update the firmware using the STM32CubeProgrammer, dfu-util, and compatible GUI apps. You need to put the device into USB DFU mode and flash .bin or .dfu images; official update procedures and drivers are documented on the tinySA wiki and community resources. For PC connectivity, the device exposes a USB CDC serial interface, enabling remote control, data streaming, and interaction with third-party companion tools such as tinySASaver and other host applications. Community support, technical guides, and firmware distribution are maintained through the wiki and a support forum where users discuss firmware versions, update processes, and troubleshooting.
The wiki has some additional useful information:
- RF inputs – The tinySA Basic uses separate low- and high-frequency RF inputs with distinct signal paths, where the low input is optimized for sensitivity at lower frequencies, and the high input is intended for higher frequencies and stronger signals. The Ultra models have an internal software-controlled switch.
- Sweep speed – The tinySA performs swept measurements rather than real-time analysis, so wide spans combined with narrow RBW settings mean slower scan times and may miss short transient signals.
- Amplitude accuracy – The Ultra models are level-calibrated up to their rated Ultra mode frequency (e.g., 5.3GHz or 7.3GHz). Beyond this, they can “observe” signals up to 12GHz, but amplitude accuracy is not guaranteed.
- Signal generator limitations – The built-in signal generator provides basic sine and square-wave outputs with limited level control and higher harmonic content, and is not designed to replace a calibrated RF signal generator.
- USB noise – Measurements taken while powering the device over USB may show additional noise or spurious signals, with battery operation generally providing cleaner RF results.
- On Ultra models, the LNA and Attenuator are mutually exclusive; you cannot enable the LNA while using the attenuator.
- Frequencies above the Normal range (typically above 800–900 MHz) are measured using internal harmonic mixing, which can produce image or “ghost” signals, so readings in Ultra mode should be interpreted with some care.
We previously wrote about the Red Pitaya board, and more recently, the Red Pitaya STEMlab 125-14 PRO Gen 2, which combines an oscilloscope, spectrum analyzer, and waveform generator in a single compact device, but it typically costs around three to five times more than a tinySA, making tinySA a far more affordable option for basic RF measurement and experimentation.
The tinySA series is available on Amazon with a price range of $57.76 (for the basic) and $260.99 (for the ultra), as well as on Zeenko’s AliExpress store, with the tinySA Basic costing around $49, the tinySA Ultra ZS-405 about $139, the ZS-406 approximately $138, and the fully featured ZS-407 going for $178. Prices on AliExpress are before taxes and shipping. We used official links from the “Where to buy” section on the wiki, where you’ll also find additional resellers and information on how to avoid low-quality clones.
Debashis Das is a technical content writer and embedded engineer with over five years of experience in the industry. With expertise in Embedded C, PCB Design, and SEO optimization, he effectively blends difficult technical topics with clear communication
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