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Erik has included features in the tinySA that even more expensive spectrum analyzers sometimes fail to include. One of those features is an ample choice of display units. The following logarithmic display units are provided: Default dBm units. Optional dBmV units Optional dBuV units The following linear display units are provided: Optional Volts units Optional Watts units Most users will be happy with just the default dBm units but there are disciplines where the other display units are the standard. The conversions from dBm are easy but having the tinySA do them eliminates errors and allows screen captures to show the correct units. It took Erik some time to get the automatic scaling to work seamlessly between all the different units, and is a example of his goal of providing features in the tinySA not seen in other devices in its price class. - Herb

Version v1.0-37 For updating see: https://tinysa.org/wiki/pmwiki.php?n=Main.UpdatingTheFirmware Changes: - completed the 3D conversion with radio buttons and checkmarks (DiSlord) - Now 51,101, 145 and 201 scan points possible

As the tinySA FW and HW are nearing completion I made a short introduction video that is available here

The testers have been asking for some extra functionality and it was still possible to fit it into the available space. Here you see two functions in one picture. One tinySA is used as signal generator and does a power sweep from -10 to -60dBm in a sweep time set to 6 seconds. Level sweep can ramp up or ramp down. The second tinySA is set to zero span and a trigger level of -12dBm and also with a saweep time set to 6 seconds. There is still a bit of switching noise in the ramp.

Measuring the 1dB compression point is a lot of work as you manually have to step through many signal levels to find the level where the detected signal is 1dB below the expected level. Using the internal step attenuator and the LINEARITY measurement in the MEASURE menu most of the manual step are automated. The green line in the picture below shows 9 measurements shown for each 1 dB step starting at 29dB attenuation. https://tinysa.org/wiki/pmwiki.php?n=Main.CompressionPoint Using an external signal generator at any of the supported low input frequencies at a level above the expected compression point level (such as +10dBm) will allow a quick measurement of the linearity. As the green line shows little disturbances below where the compression starts it is safe to conclude the internal step attenuator is very linear.

One of the beta testers did a very good job at measuring the power linearity of an uncalibrated tinySA. Uncalibrated implies the absolute level may be a couple of dB off but the relative steps should be accurate First the low input And the high input From these measurements that are a couple of conclusions. The 1dBc of the low input is possibly at or a bit above 0dBm The 1dBc of the high input is expected to be close to -10dBm The low input LPF is at -3dB around 300MHz and at -6dB at 350MHz. This will have to be compensated for. Below 1MHz the low input is having some problems. These possibly can be corrected by adjusting AGC and LNA Below 0.4MHz the phase noise limits the low end of the power measurement range The high input is flat +/- 1.5dB over the whole range The power level measurement is close to the official +/- 1dB overall linearity. Overall this measurement confirms the spec on the wiki. https://tinysa.org/wiki/pmwiki.php?n=Main.Specification

Greetings Erik, A common problem for radio amateurs is the proliferation of modern day RFI sources that cause significant interference particularly to the HF bands. IMHO a portable low cost spectrum analyzer that includes some specific features intended to support tracking down noise sources would be of significant interest for many hams. Often noise sources are related to the power line frequency. It has been well documented elsewhere that because there are often multiple A/C power related RFI sources around the home and within the local hydro grid that an ability to record the time domain signature of the most offending noise is helpful for identifying the most significant cause. Once a problem is located within one's home it can usually be corrected. If a power grid problem is pinpointed it has been experienced that usually the utility will repair it expediently. Spectrum analyzers with time domain signature waveform comparison capability are now used by many utility companies for locating RFI sources. I found it interesting that that the tinyVNA firmware already offers a zero span mode with time domain display capability. I wonder if the time domain display could be designed to lock on to a hydro buzz type of noise and store a few cycles? If this were implemented the offending RFI waveform signature could be compared to noise sources found in the field to help identify the source. Possibly a split screen display with the stored waveform shown within the top half and real time waveform in the bottom half would offer a convenient means for the user to compare signatures. I am interested in evaluating a tinyVNA for the purpose of tracking down RFI sources. Best Regards, Tom, VA7TA

How close to a carrier I can get? Many Hams, educators and me would like to see and check their modulators. That is, can I see what does spectrum of SSB with 1kHz modulation look like. Or 300Hz and closer.