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Frequently Asked Questions

Question
Will there be a 4" or larger version of the tinySA?
Answer
To reach the largest set of customers it was deliberately decided to first launch the 2.8" version of the tinySA. Next steps will depend on continued sales . A 4" version is expected to fit within the cost and affordable sales price but design has not started. Larger display's are not expected as these will have a substantial cost impact. For the coming months all effort will go to supporting the initial customers and, if required, further maturing the 2.8" version.
Question
Will there be a 2GHz (or 4GHz) version?
Answer
This is being studied but there is no plan yet
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 600kByte 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
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
Am I limited to maximum 290 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 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
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
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
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
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
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
Where is the VBW setting?
Answer
The tinySA does not have a VBW setting for noise reduction, it is advised to use the LEVEL/CALC/AVER function instead
Question
My signal was frequency X but the tinySA says it is Y?
Answer
The total scan range is divided in 290 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 290 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
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
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
Is there an Android App for the tinySA?
Answer
Not yet, but once there is sufficient free time I will have a look.
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Page last modified on October 23, 2020, at 06:31 PM