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Frequently Asked Questions

Common questions

Question
Is the tinySA really doing what is promises?
Answer
At https://groups.io/g/tinysa you will find a user community with more than 2000 happy users as members.
Question
Is the tinySA using the same HW as the nanoVNA?
Answer
No, the tinySA HW is very different from the nanoVNA and specifically optimized for its spectrum analyzer and signal generator functions. The tinySA does however use the same display, battery and housing as the nanoVNA-H
Question
Does the tinySA contain a Tracking Generator?
Answer
The generator function can not be used as a tracking generator as you can not use the spectrum analyzer and generator functions at the same time.
Question
Why is a wide scan with a low RWB so slow?
Answer
There are two factors that make the scan speed decrease. With a large span and a low RBW additional measurement points are inserted to avoid missing signals. Scanning 100MHz with a RBW of 10kHz requires 20000 measurements where using a 600kHz RBW would only use 290 measurements. The RBW filter is implemented in low sample rate DSP and the filter needs time to charge where the charging time is inverse proportional with the RBW. a 3kHz RBW requires more then 7 milliseconds measurement time per measurement point where a 600kHz RBW only requires 0.3 milliseconds.
Question
HELP, my tinySA crashes at startup with a stack dump or hangs
Answer
Open the case, unplug the battery, count to 10, reconnect the battery, close case.
Question
How are the additional inserted measurements consolidated into one displayed measurement?
Answer
The displayed measurement is the maximum of all the additional measurements to ensure the level of a signal falling within only one measurement is correctly displayed.
Question
Am I limited to maximum 290 or 450 scan points?
Answer
In standalone operation the scan can use many measurement points with a large span and low RBW but the display is always using maximum 290 or 450 points. When using the tinySA in combination with a PC the amount of points is unlimited. The Windows control program supports scanning with up to 30000 measurement points.
Question
In zero span mode there is a weird modulation visible, even when I apply a constant level input signal
Answer
When the input signal is very close to the zero span center frequency some yet unexplained interference occurs causing +/- 1dB variations in detected level. This can be eliminated by offsetting the zero span center frequency with 1/4 RBW.
Question
Is the design of the tinySA public domain?
Answer
The tinySA schematic and PCB design are not public domain. The embedded software of the tinySA is FOSS (free and open source software) according to the GPL v3 and can be found at https://github.com/erikkaashoek/tinySA
Question
My signal was frequency X but the tinySA says it is Y?
Answer
The total scan range is divided in points with equally spaced frequencies. The tinySA uses these frequencies for the markers, even when using an RBW much smaller then the frequency step between the points. Furthermore the tinySA takes steps of at least a quarter of the active RBW so any frequency reported has an uncertainty of at least that amount.
Question
Self test 3,4, 7 and 10 fail. What can be wrong?
Answer
This is happening when the observed level of the calibration output is wong. Did you connect high and low connectors? Is the used SMA cable OK? Did a power level calibration fail? If so, redo the power level calibration and run the self test again.
Question
The Attenuator self test fails (test 10 and 12 in the latest FW). What can be wrong?
Answer
This could be caused by a faulty attenuator. Here you can find how to check the attenuator

tinySA Ultra questions

Question
The tinySA Ultra hangs or crashes with a stack dump
Answer
Switch off, push jog button to the side and switch on again. Do a CONFIG/MORE/CLEAR CONFIG 1234 and restart without pushing the jog button to the side.
Question
The tinySA Ultra is does not react to touch commands or the jog button
Answer
The LCD cable may not be seated correctly. Open the case and carefully lift the black clip holding the LCD cable at both edges till it swings up. Reseat the cable and press the black clip down till it clicks in position.
Question
I'm not able to use touch for menu selection and I can not activate the touch calibration
Answer
Use the jog button to activate the menu and left/right/down of the jog button to select the menu option. If the touch calibration keeps failing loosen the screws of the shell a bit to reduce the pressure of the front of the shell on the touch the screen.
Question
Why is the zero span mode of the tinySA Ultra slower then the tinySA?
Answer
The tinySA Ultra uses a different component to enable small RBW but has the disadvantage of being slower.
Question
The LNA is not working. Where can I find a new LNA?
Answer
The LNA is U14, type number BGA2817, available from many suppliers
Question
The input switch is blown. Where can I find a new switch?
Answer
The input switch is U22, type number XA17-G4K.
Question
The screen is frozen and neither touch nor the jog button works, what to do?
Answer
Slowly loosen the 4 case screws at the back till the screen becomes responsive.

tinySA Basic questions

Question
I'm not able to use touch for menu selection and I can not activate the touch calibration
Answer
Use the jog button to activate the menu and left/right/down of the jog button to select the menu option. If the touch calibration keeps failing loosen the screws of the shell a bit to reduce the pressure of the front of the shell on the touch the screen.
Question
Why do the low and high input modes perform so different?
Answer
The low input mode has an input attenuator to avoid overloading and a good band pass filter to eliminate mirrors. The high input mode is a "for free" feature and we decided to make it available as, even with its limited performance, it could be useful.
Question
Can I inspect the SSB modulation of my transmitter?
Answer
As the minimum RBW is 2.7kHz it is impossible to look at details inside a 2.7kHz wide SSB signal. With careful setup it is just possible to check the alternate side band rejection or see the carrier rejection.
Question
Why does my signal have some unexpected weird side lobes when I zoom in?
Answer
The implementation of the resolution filters suffers from some spectral leakage due to the chosen DSP implementation.
Question
Why can't I do a screen capture of the version screen?
Answer
As long as the tinySA is in a busy wait in the UI there is insufficient memory for the execution of screen captures.
Question
How can I get a new rocker switch/internal switch/attenuator?
Anwer
These are available in single piece quantities with Mouser and other component vendors. The rocker is compatible with PL3-AC-V-T/R, the internal switch (U8 for low and U6 for high) is compatible with AS179-92LF and the attenuator (U9) is compatible with a PE4312C-Z
Question
In zero span mode there are weird spikes visible in my AM modulated signal
Answer
The AGC used to extend the dynamic range of the power detector has difficulty to react to very fast level changes, as a consequence the power detector may show deviations from the actual input signal. To test if this is happening one can disable the AGC in CONFIG/EXPERT CONFIG/MORE/AGC.
Question
Even without anything connected I still see some signals
Answer
The shielding of both the high and low input can not prevent strong transmitters from entering. A nearby FM, DAB, TV or mobile phone transmitter can be visible. In high input mode the harmonics of the 30MHz TCXO generating the clock frequencies are visible over the full frequency range at or below -95dBm. The low input is susceptible to the harmonics of the 48MHz MCU clock. When doing a 0-350MHz scan with an RBW of 10kHz these are clearly visible. The latest FW version effectively eliminates these MCU clock harmonics.
Question
I'm trying to measure AM modulation but the measurement seems completely wrong. What can be done?
Answer
When measuring AM modulation you have to carefully adjust some settings otherwise the measurement will fail. More info available in the page on measuring AM modulation
Question
Is there an Android App for the tinySA?
Answer
Not yet, but once there is sufficient free time I will have a look.
Question
Does my tinySA have ESD protection diodes
Answer
Make sure you have FW v1.3-3 or later. Go to CONFIG/VERSION. If the last line of the displayed version info is "ESD protected" the diodes are installed.
Question
After calibration the CAL output level at 30MHz reads a bit low, is this a problem
Answer
On some tinySA the CAL output level at 30MHz after calibration is measured a bit on the low side, levels down to -27.2dBm are not a problem given the nominal level of -26dBm.
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Page last modified on August 22, 2023, at 11:03 AM