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Hello Enrique,

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I just tested my TinySA Ultra using the same signal generator output settings that you are using and it appears to provide the correct approximate signal level when tested into an open circuit condition (high impedance condition).

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In my test setup I ran the output of the TinySA Ultra to my oscilloscope using a x1 probe so the TinySA 50 ohm output was looking into a relatively high impedance load (let's say open circuit).? Assuming the load was really 50 ohms versus the open circuit condition then my oscilloscope readings would be half of what it really measured.? You will see that I measured 2.31 mV RMS into an open circuit load so if the load was really 50 ohms I would have measured 2.31mV/2 = 1.155 mV.? Then if I calculate the power into a 50 ohm load it would be ((1.155 mV)*(1.155 mV))/50 ohms = 0.0267uW which equals -45.7 dBm which is pretty close to the -48.1 dBm output setting.? The signal level is so low that the 2.31 mV RMS measurement using my oscilloscope is just an approximate value as is the "open circuit" condition I assumed.? I don't see anything unusual, and the TinySA Ultra was indeed generating a signal at 50 KHz as shown in my attached picture.

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P.S. make sure you are using capacitive coupling (DC block, etc.) between the output of the TinySA Ultra and your test circuit (or make sure the test circuit DC voltage is near zero) so you don't feed excessive DC voltage back into the output of the TinySA Ultra.

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Just FYI,

Don?

I want to report back. I've got a low pass filter (f_c=6 GHz) and the 8 GHz signal was still there - so it is indeed a mirror as Erik suggested.

If i take a closer look, it seems to be a mirror of the 2 GHz wideband LTE signal. Case closed! Thanks for the help.

Thanks!!

The cables that come with the tinySA Ultra have about 0.5 dB loss at 5 Ghz and 0.25 dB loss at 2.5 GHz

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Designer of the tinySA
For more info go to

Specifically interested in 2.4GHz wifi range and 5GHz UNII 1, 2A, 2C, and 3 range. I know my measurements won't be anything to take to the bank on the TinySA in Ultra mode, but was hoping to get a ballpark idea of channel power in some configurations. This looked like a good option outside of spending 13k+ on a Keysight MXA haha.

Are there any available spec sheets for the kit SMA cables? Hoping to find a table or chart of insertion losses in dB.

The processor of the tinySA is not fast enough to produce a usable pseudo noise.

And there is insufficient space to add a HW noise generator without impacting the SA performance.

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Designer of the tinySA
For more info go to

Hello,

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Last year I purchased a TinySA Ultra in order to make some alignments in my old HF receivers, a pair of Drake SPR-4.

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To say the truth I purchased the Tiny because it goes down to 50 Khz and finding a signal generator that covers from 10/ 50Khz is quite difficult and expensive.

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I have problemms in making the alignment and I do not know if is the generator or some other part. Starting the alignment with the IF 50Khz BFO? is quite easy, first coil can zero beat the note but the following coils there is no movement? either in voltmeter or S-meter.

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I have tried with passive and active probes because I suppose that is a high impedance circuit. Maybe am I doing something wrong with the generator? Is the input typed wright, as the attached photo shows?

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This is the manual: page 23

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QtTinySA should work with all genuine hardware versions and the arm64 binary works (and was compiled on) on my Pi4.? I only have the Ultra so I can't test other versions.

There has been the occasional firmware version that didn't work.? I have not tested firmware v1_4_175 but I have tested 177, 189, 193 and 199 which all work, as do a lot of the earlier versions.

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From 177 onwards, Erik updated the firmware for me to allow the 'scanraw' command to loop and scan continuously.? This made a noticeable improvement to the QtTinySA scanning speed, so unless you have some particular reason for not updating to a later version there is an advantage in being on 177 or later.

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I am happy to help more but this is Erik's forum so please raise the issue on

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Please post the output of the terminal screen.? In terms of 'remote access', I use my Pi4 running QtTinySA over 'tigerVNC' and it works very well on my gigabit LAN.

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Ian

It is clear that the noise will not be completely white. But the generator will be the same in all TinySAs and it will be possible to exchange the results , for example, of NPR measurements.

I am using Tinysa over USB to Ethernet solutions, and QTTinySA

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I was wondering if TinySA could allow the Sweep Accuracy Features to be changed via PC control, currently I am loading a profile before the device is used in a remote mode, but would love to be able to change these remotely.

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- Normal/Precise/Fast/Noise (Selection Box)
- NSpeedup
- WSpeedup

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Yes, but the noise quality as you increase frequency

will be poor. In software (on MPU) the way to get

noise is implement pseudo random? sequence for

rate and amplitude but?you do not get white noise

as its bandwidth limited.

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An external diode noise source is generally better

and easily characterized.

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Allison

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Please post here, direct emails go to a dead letter box.

I have a similar noise source and the easy way to lower its output

is an attenuator 20-30db should be adequate.? Saves digging into

the circuit.

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Allison

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Please post here, direct emails go to a dead letter box.

I'm trying to use a Pi 4B to view/control TinySA.

I've sucessfully installed QtTinySA on a clean image and it works just fine with a TinySA Ultra+

I've had a TinySA in my bag as a "don't leave home without it" device for a few years and tried connecting it instead of the Ultra.

I can see it if I run lsusb so there is a connection, but it is not recognised by QtTinySA

It does connect to a Win PC and i have updated it to 1.4.175

I've reread the QtTinySA Wiki and I can't see any reference that it only supports Ultra.

Am I missing something obvious?

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I'm keen to see if I can develop into a remote access Spectrum Monitoring device. We have a fleet of them based on other hardware.?

Any help appreciated.

Cheers

Peter

Good afternoon. I am aware of this generator. I have three of them, all slightly upgraded as the noise is very dirty. the latter has everything done to produce pure white noise at least on HF . I also have https://github.com/k3it/osa103-mini ?ysclid=maxxsxro82487715627 it has the NG function, but it is not standalone. I would like to have NG in TinySA.

73! R1BLT Alexander?

Be careful with those noise sources from e.g. BG7TBL.? Mine puts out +8dBm of wideband noise, which is enough to compress or even possibly damage a sensitive input like on the TinySA.

If you compress the receiver when calibrating you will get inflated numbers when measuring items like filters

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My BG7TBL generator has 3 MMICs in series after the noise diode; I plan to take the output from earlier in the chain to see if I can get a more-reasonable output level.? Mine has an excess noise ratio (ENR) of over 100dB, commercial units typically are 5 or 15dB ENR.? Of course I could just add attenuation but removing MMICs will also lower the fairly high power consumption, which makes the board hot and changes the output level..

73, Don N2VGU